Abstracts of the European Vitreoretinal update 14th Euretina Congress, 2014, London, England.

Abstracts

Ophthalmologica

Ophthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

Main Session 1: Dry AMD

Aging, Degeneration, Inflammation, Apoptosis: Mechanisms of AMD Chi-Chao Chan Immunopathology Section, Laboratory to Immunology, National Eye Institute, National Institutes of Health, USA

Age-related macular degeneration (AMD) is an aging disease of the outer retina, characterized most significantly by atrophy of photoreceptors and retinal pigment epithelium, which is sometimes accompanied by choroidal neovascularization. Development of AMD is contingent on both environmental and genetic risk factors, the strongest being advanced age. With normal aging, photoreceptors are steadily lost, Bruch’s membrane thickens, the choroid thins, and hard drusen may form in the periphery. The changes are characterized as kinetics between homeostasis and allostasis. In AMD, many of these changes are exacerbated (chronic allostatic overload leading to pathology and disease); additionally, there is development of disease-specific factors such as soft macular soft drusen, geographic atrophy, and choroidal neovascularization. Para-inflammation, which can be thought of as an intermediate between basal and robust levels of inflammation, develops within the retina in an attempt to maintain ocular homeostasis and physiological allostasis, reflected by increased expression of the anti-inflammatory cytokine IL-10 coupled with shifts in macrophage plasticity from the pro-inflammatory M1 to the anti-inflammatory M2 polarization. In AMD, imbalances in the M1 and M2 macrophage populations and activation of retinal microglia are observed and potentially contribute to tissue degeneration. In the chronic © 2014 S. Karger AG, Basel 0030–3755/14/2325–0001$39.50/0 E-Mail [email protected] www.karger.com/oph

Published online: September 11, 2014

stage of allostatic overload, including oxidative stress, inflammasomes and inflammatory cytokines (e.g., IL-1β, IL-17 and IL-18) wax and wane; retinal pigment epithelium and photoreceptors degenerate, leading to apoptosis, autophagy, pyrotosis, and atrophy. Neovascularization may also develop. Therefore, the underlying mechanism of AMD involves homeostasis, allostasis, and allostatic overload, which all depend primarily on aging, degeneration, inflammation, pyrotosis, apoptosis, autophagy, and neovascularization.

Dry Age-Related Macular Degeneration: Mechanisms, Therapeutic Targets, and Imaging Cynthia A. Toth Duke Eye Center, Box 3802, Durham, NC, 27710 E-Mail [email protected]

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in people over 60 in Europe and in the US. Patients with early and intermediate AMD have drusen, although non-central geographic atrophy may be included in some categories of intermediate disease. Visual function, including dark adaptation and low level visual acuity may be affected despite moderate retinal disease appearance. Advanced disease is generally characterized as neovascular or atrophic AMD (geographic atrophy), although both may occur in the same eye. While choroidal neovascularization, generally responds to anti-vascular endothelial growth factor therapy, we lack therapies to prevent progression of atrophy whether in isolation or associated with neovascularization. We also are unable to restore useful vision in eyes with profound vision loss from geographic atrophy.

While Age-Related Eye Disease Study (AREDS) and AREDS2 oral supplements (antioxidant vitamins C and E, lutein, zeaxanthin, and zinc (plus copper)) have been shown to reduce the risk of progression to advanced AMD, the effect was in neovascular rather than atrophic AMD. There are several features of early AMD that are likely to be targets for therapeutic intervention. Much of the genetic risk for AMD has been shown to be associated with complement factor related genes. Multiple complement-factor-based therapeutic treatment approaches are being pursued. Some of these treatment strategies target drusenoid deposit formation and specific protein and/or lipid deposition in the fundus. Also, limiting oxidative stress through modulation of the anti-oxidant system may play a role. In addition, modulating the transport of organelles and protein aggregates to the lysosome in RPE cells in AMD (macro autophagy) may be a therapeutic option. Alternately, intervention to modulate microglial or macrophage subtype accumulation are under consideration. To properly characterize disease progression which is essential for the evaluation of effects of new therapies in clinical trials relies on methods that were not available in the phenotyping AMD studies of the 1980s and 90s. Novel imaging modalities such as high resolution optical coherence tomography (OCT) imaging allow for early detection and more precise measurement of disease stage and change in stage. Substructures of disease (types of drusen based on OCT reflectivity), patterns of disease (reticular drusen) and associated changes in critical tissues (retinal or choroidal layers) all may contribute to characterization of a patient’s risk of progression. Longitudinal studies demonstrate how such imaging will improve prediction of disease progression. Linking the imaging of retinal structures to function, will add to this transformation of AMD assessment.

4 Ding JD, Johnson LV, Herrmann R, et al: Anti-amyloid therapy protects against retinal pigmented epithelium damage and vision loss in a model of age-related macular degeneration. Proceedings of the National Academy of Sciences of the United States of America 2011;108:E279– E287. 5 Johnson LV, Leitner WP, Staples MK, Anderson DH: Complement activation and inflammatory processes in Drusen formation and age related macular degeneration. Experimental eye research 2001;73:887–896. 6 Gupta N, Brown KE, Milam AH: Activated microglia in human retinitis pigmentosa, late-onset retinal degeneration, and age-related macular degeneration. Experimental eye research 2003;76:463–471. 7 Cousins SW, Espinosa-Heidmann DG, Csaky KG: Monocyte activation in patients with age-related macular degeneration: a biomarker of risk for choroidal neovascularization? Arch Ophthalmol 2004;122:1013– 1018. 8 Mettu PS, Wielgus AR, Ong SS, Cousins SW: Retinal pigment epithelium response to oxidant injury in the pathogenesis of early age-related macular degeneration. Mol Aspects Med 2012;33:376–398. 9 Khanifar AA, Koreishi AF, Izatt JA, Toth CA: Drusen ultrastructure imaging with spectral domain optical coherence tomography in age-related macular degeneration. Ophthalmology 2008;115(11):1883–1890. 10 Leuschen JN, Schuman SG, Winter KP, et al: Spectral-domain optical coherence tomography characteristics of intermediate age-related macular degeneration. Ophthalmology 2013;120(1):140–150. 11 Jain N, Farsiu S, Khanifar AA, et al: Quantitative Comparison of Drusen Segmented on SD-OCT versus Drusen Delineated on Color Fundus Photographs. Investigative ophthalmology & visual science 2010;51: 4875–4883. 12 Schuman SG, Koreishi AF, Farsiu S, et al: Photoreceptor Layer Thinning over Drusen in Eyes with Age-Related Macular Degeneration Imaged In Vivo with Spectral-Domain Optical Coherence Tomography. Ophthalmology 2009;116:488–496. 13 Chiu SJ, Izatt JA, O’Connell RV, et al: Validated Automatic Segmentation of AMD Pathology Including Drusen and Geographic Atrophy in SD-OCT Images. Invest Ophthalmol Vis Sci 2012;53:53–61. 14 Farsiu S, Chiu SJ, O’Connell RV, et al: Quantitative Classification of Eyes with and without Intermediate Age-related Macular Degeneration Using Optical Coherence Tomography. Ophthalmology 2014;121:162–172. 15 Christenbury JG, Folgar FA, O’Connell RV, et al: Progression of Intermediate Age-related Macular Degeneration with Proliferation and Inner Retinal Migration of Hyperreflective Foci. Ophthalmology 2013;120: 1038–1045. 16 Owsley C, Jackson GR, Cideciyan AV, et al: Psychophysical evidence for rod vulnerability in age-related macular degeneration. Invest Ophthalmol Vis Sci 2000;41:267–273.

Complement Inhibition in the Treatment of AMD Zohar Yehoshua, Philip J. Rosenfeld 900 NW 17th street, Miami, FL 33136

References 1 Kaarniranta K, Sinha D, Blasiak J, et al: Autophagy and heterophagy dysregulation leads to retinal pigment epithelium dysfunction and development of age-related macular degeneration. Autophagy 2013;9:973–984. 2 Curcio CA, Johnson M, Rudolf M, Huang JD: The oil spill in ageing Bruch membrane. The British journal of ophthalmology 2011;95:1638– 1645. 3 Hageman GS, Luthert PJ, Victor Chong NH, Johnson LV, Anderson DH, Mullins RF: An integrated hypothesis that considers drusen as biomarkers of immune-mediated processes at the RPE-Bruch’s membrane interface in aging and age-related macular degeneration. Progress in retinal and eye research 2001;20:705–732.

2


The use of complement inhibitors was proposed when genetic studies elucidated the role of the complement system as an important factor in AMD. The complement system can be modulated by various classes of drugs. All levels of the cascade can be influenced. Protein-binding and protein inhibiting substances such as antibodies (LFG316, FCFD4514S, eculizumab), peptides (POT-4), and aptamers (ARC1905) have a targeted effect on one Abstracts

component of the complement system (e.g. C3, C5, Complement factor D). A number of clinical studies using complement inhibitors have been ended early as a result of disappointing interim results, and others with no reason reported. Recently, promising results from the MAHALO study have been revealed. Lampalizumab is a new monoclonal antibody that inhibits complement factor D, which is a rate-limiting enzyme of the alternative complement pathway. Increased activation of this pathway, which is a component of the immune system’s defense against infections, is associated with the development of macular degeneration. For the first time, efficacy in terms of slowing atrophy progression has been demonstrated when lampalizumab was administered intravitreally in monthly intervals has proved to be safe and to slow lesion growth in eyes with GA in a phase 2 study (MAHALO study; NCT01802866) [1]. The positive phase 2 results from the showed a 20.4% reduction rate in the area of geographic atrophy at 18 months in patients with advanced dry AMD. Efficacy of lampalizumab was observed in a specific sub-population of GA patients treated monthly with lampalizumab that were identified using exploratory biomarkers (Factor I), the GA progression rate was decreased by 44% at 18 months. Factor I was not only a prognostic biomarker but a predictive one. Eculizumab is a humanized monoclonal antibody that inhibits the complement cascade at C5, preventing the formation and release of the downstream anaphylatoxin C5a and the formation of the cytolytic membrane attack complex. A phase 2 trial (COMPLETE Study; NCT00935883) failed to demonstrate efficacy of intravenously administered eculizumab in patients with advanced dry AMD [2]. Possible explanations for the lack of a treatment effect could be that the dose of eculizumab was too low or that the drug should have been delivered as a direct intravitreal injection to achieve an adequate level of drug in the retina or the RPE [2]. POT-4 is a cyclic, 13-aa peptide that prevents the conversion of C3 to C3a and C3b. A phase 1 study in neovascular AMD has been completed (NCT00473928). The therapeutic effect of POT-4 may not be sufficient to prevent complement activation, as it can still be activated via the classical and the lectin pathways. A treatment trial is planned in patients with dry AMD. LFG316, C5 inhibitor is an intravitrally administered antibody. It is currently being evaluated in a phase 2 study in patients with GA (NCT01527500). The option of genetic therapies that lead to the expression of complement-regulating proteins (e.g. CD46,

CD59), and injection of recombinant proteins (e.g. C1INH, sCR1, CFH), are being investigated in preclinical trials. These substances possess a wide range of targets and drugs.

Abstracts


References 1 Regillo CD: Lampalizumab (anti-factor D) in patients with geographic atrophy: the MAHALO phase II results. Program and abstracts of the American Academy of Ophthalmology 2013 Annual Meeting; November 15–19, 2013; New Orleans, Louisiana. 2 Yehoshua Z, et al: Systemic complement inhibition with eculizumab for geographic atrophy inage-related macular degeneration: The COMPLETE study of ophthalmology. Ophthalmology 2013;S0161– S6420.

Main Session 2: Diabetic Retinopathy

Retinal Oximetry and the Evaluation of Retinal Metabolism Einar Stefánsson, Sveinn Hákon Harðarson, María Soffía Gottfreðsdóttir, Ólöf Birna Ólafsóttir, Þóra E. Jónsdóttir, J. Valgerður Kristjánsdóttir, Sindri Traustason, Þór Eysteinsson, David Thor Bragason, Thorunn S. Elíasdottir, Olafur Palsson, James Beach Univ. Iceland, Oxymap ehf*, Iceland E-Mail [email protected]

Spectrophotometric retinal oximetry measures oxygen saturation of hemoglobin in retinal arterioles and venules. Noninvasive retinal oximetry in humans is based on conventional fundus camera or scanning laser ophthalmoscopy. Retinal oximetry is very stable in healthy individuals with oxygen saturation 92.2 ± 3.7% (mean ± SD) in retinal arterioles and 55.6 ± 6.3% in venules and decreases slightly with age. It responds significantly to changes in oxygen breathin and documents changes in retinal energy metabolism in light and dark. Retinal oximetry has demonstrated abnormal oxygen metabolism in several major eye diseases. In diabetic retinopathy, the oxygen saturation of retinal venules increases with advancing retinopathy. This indicates maldistribution of blood flow and oxygen due to capillary nonperfusion patches. 3

Retinal vein occlusions show dramatic hypoxia in retinal venules and this is variable, possibly according to the severity of the occlusion. In retinal artery occlusions, hypoxia is demonstrable in the arterioles. Age related macular degeneration shows oxygen saturation profiles, which are significantly different from healthy controls. It is tempting to relate the abnormalities in oxygen metabolisms with the role of (hypoxia induced) vascular endothelial growth factor in diabetic retinopathy, retinal vein occlusions and AMD. In glaucoma retinal oxygen saturation increases with more severe visual field defects and retinal atrophy and the arteriovenous difference and oxygen delivery decreases. Here the oxygen delivery may reflect cell death – dead cells do not use oxygen. Similar findings are seen in retinitis pigmentosa, where oxygen use is also diminished with advancing disease. Retinal oximetry is a noninvasive method to image retinal oxygen metabolism in health and disease. It opens a new metabolic dimension in retinal imaging, which is very relevant in metabolic and ischemic diseases of the eye.

The EURETINA Project for Diabetic Retinopathy Screening Einar Stefánsson Univ. Iceland

Diabetic retinopathy remains a major cause of preventable blindness in the world. The public health risk from diabetic eye disease is rapidly rising with the global diabetes epidemic, which is projected to exceed 500 million people in the foreseeable future. The efficacy of diabetic eye screening and preventive laser treatment was established more than 25 years ago and is recognized by WHO and most professional organizations in ophthalmology and diabetology. However, the majority of diabetic patients in the world do not benefit from such screening. As a consequence, diabetic blindness is much more frequent than need be and probably millions of people suffer preventable loss of vision. Annual diabetic eye screening was initially shown to reduce diabetic vision loss and blindness by as much as 70–80%. More recently it has been demonstrated that less frequent screening may give the same benefit. Biennual screening for diabetic patients without retinopathy is safe 4


and effective. Individualized screening, which is based on individual risk assessment, tailors the screening frequency to the severity of disease and risk for progression. This approach gives more frequent screening to high risk individuals, whereas low risk diabetic patients may be screened less frequently. With this approach the overall screening frequency may be reduced by about 60% without compromising clinical outcome and safety. Consequently, the cost of diabetic screening programs can be cut in half. EURETINA recognizes the need for a global effort to reduce diabetic blindness. The Society has decided to use its powers to promote diabetic eye screening in Europe and elsewhere.

Phenotype-Genotype Associations in Nonproliferative Diabetic Retinopathy José Cunha-Vaz1,2 1Association

for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 2Faculty of Medicine, University of Coimbra, Coimbra, Portugal E-Mail [email protected]

Diabetic retinopathy (DR) is one of the most common complications of Diabetes Mellitus and one of the major causes of vision loss in the Western world [1]. The natural history of initial diabetic retinal lesions has particular relevance for understanding the disease. Progression of DR does not occur at the same rate in all diabetic patients. It is clear that in some patients DR progresses very slowly, without development in the shortterm of vision loss, whereas in others, even under similar duration of diabetes and metabolic control, there is a rapid advance to macular edema or neovascularization leading to vision loss. This strongly suggests the possibility of a genetic predisposition to retinopathy. Preliminary analysis of a clinically well-characterized sample size and a large number of genetic variants would collectively aid in defining the genes and the potential variants involved in the DR disease pathology. The monitoring of the initial DR alterations by multimodal macula mapping identified three different progression phenotypes in non-proliferative DR [2]. These phenotypes have been confirmed in a recent two-year prospective study using only non-invasive methods, fundus photography and spectral-domain optical coherence tomography (SD-OCT). The first phenotype, designated A, is characterized by a low microaneurysm (MA) turnAbstracts

over and normal central retinal thickness (RT). Patients with phenotype B are characterized by an abnormally higher central RT, and patients of phenotype C are characterized by higher MA turnover [3]. These phenotypes show different patterns of progression and, additionally, patients belonging to the phenotypes B and C have a higher risk for Clinically Significant Macular Edema (CSME) development, requiring treatment. Three hundred and seven patients (307) were evaluated, men and women with diagnosed adult-onset type-2 diabetes, age 40 to 78 years, mild non-proliferative DR (20 and 35 of the ETDRS classification) and best corrected visual acuity ≥ 95 ETDRS letters in the study eye. The following 11 candidate genes were selected for genotyping: ACE – angiotensin I converting enzyme (peptidyl-dipeptidase A) 1; AGER – advanced glycosylation end product-specific receptor; AKR1B1 – aldo-keto reductase family 1, member B1 (aldose reductase); ICAM1 – intercellular adhesion molecule 1; MTHFR – methylenetetrahydrofolate reductase (NAD(P)H); NOS1 – nitric oxide synthase 1 (neuronal); NOS3 – nitric oxide synthase 3 (endothelial cell); PPARGC1A – peroxisome proliferator-activated receptor gamma, coactivator 1 alpha; TGFB1 – transforming growth factor, beta 1; TNF – tumor necrosis factor; VEGFA – vascular endothelial growth factor A. Genotyping was performed using the TaqMan® OpenArray® Genotyping System from Life Technologies at the Genoinseq, the Next Generation Sequencing Unit of Biocant, Cantanhede, Portugal. The Hardy-Weinberg equilibrium (HWE) was tested for all SNP genotype frequencies in the whole patient sample and also for subgroups of patients with Phenotype A and Phenotypes B or C, using the Pearson χ2 test or the Fisher exact test. Seventy nine (79) patients (25.7%) having both eyes as phenotype A were categorized in phenotype A; 79 patients (25.7%) having both eyes as phenotype B, or one eye as phenotype B and the other as phenotype A, were categorized as phenotype B; and 149 patients (48.6%) having one or two eyes as phenotype C were categorized as phenotype C. The results of the Multivariate Logistic Regression analysis show associations between ICAM1, PPARGC1A and MTHFR and the phenotypes of DR progression after adjusting for gender, age, diabetes duration and HbA1C. Regarding gene PPARGC1A, rs10213440 was associated with phenotype C (P = 0.030), compared with phenotype A, with an adjusted OR of 2.00. MTHFR rs1801133 was associated with Phenotype C when compared with Phenotype A showing an adapted OR of 1.84. Abstracts

The multivariate analysis results indicated an association between the gene ICAM1 and the development of CSME after adjusting for gender, age, diabetes duration and HbA1C. This preliminary phenotype-genotype association study suggests that, in some patients, there are specific genetic variants which make some patients more susceptible to alteration of the BRB and inflammation whereas others develop a more aggressive microvascular disease associated with the development of angiogenic imbalance.

References 1 Yau JWY, Rogers SL, Kawasaki R, et al: Global prevalence and major risk factors of diabetic retinopathy. Diabetes care 2012;35(3):556–564. 2 Lobo C, Bernardes R, Figueira J, de Abreu J, Cunha-Vaz J: Three-year follow-up study of blood-retinal barrier and retinal thickness alterations in patients with type 2 diabetes mellitus and mild nonproliferative diabetic retinopathy. Arch Ophthalmol 2004;122(2):211–217. 3 Nunes S, Ribeiro L, Lobo C, Cunha-Vaz J: Three different phenotypes of mild nonproliferative diabetic retinopathy with different risks for development of clinically significant macular edema. Invest Ophthalmol Vis Sci 2013;54(7):4595–4604.

The EUROCONDOR Project Rafael Simó, on behalf of EUROCONDOR Professor of Medicine and Endocrinology, Autonomous University of Barcelona, Director of Diabetes and Metabolism Research Unit, Vall d’Hebron Reseach Institute (VHIR), Barcelona, Spain

Diabetic retinopathy (DR), one of the leading causes of preventable blindness, has been considered a microcirculatory disease of the retina. However, there is emerging evidence to suggest that retinal neurodegeneration is an early event in the pathogenesis of DR, which participates in the development of microvascular abnormalities. Therefore, the study of the underlying mechanisms leading to neurodegeneration and the identification of the mediators in the crosstalk between neurodegeneration and microangiopathy will be essential for the development of new therapeutic strategies. In my speech, an overview of the mechanisms involved in neurodegeneration with special emphasis to the role of somatostatin (SST) will be presented. Finally an update of the EUROCONDOR project, the first clinical trial addressed to evaluate the effectiveness of neuroprotective agents (SST and brimonidine) in the early stages of DR will be given. Ophthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

5

Novelties in the Field of Diabetic Macular Edema Maurizio Battaglia Parodi, Ilaria Zucchiatti, Maria Lucia Cascavilla, Francesco Bandello Department of Ophthalmology, University Vita-Salute, Ospedale San Raffaele, Milano, Italy E-Mail [email protected]

Diabetic retinopathy (DR) is a leading cause of visual impairment in many countries. In an attempt to reduce the burden of the disease, the identification of features able to predict the severity of the clinical involvement could be crucial. Over the last few years the physiopathological mechanisms leading to the development of the early stages of the disease have been largely investigated. In particular, several studies focused on the identification of biomarkers, which can correlate with the activity and the progression of the DR. Even though DR has been primarily considered as a retinal microvascular disorder caused by the direct effects of hyperglycemia and the altered metabolic pathways, recent studies have demonstrated that retinal neurodegeneration plays a role in the early stages of the disease. Instrumental tests including electroretinography, dark adaptation, contrast sensitivity, microperimetry, and optical coherence tomography (OCT) can detect response changes before that the DR could be clinically evident. Thus, many morpho-functional and psycophysical tests seem to be more sensitive indicators of retinal integ-

rity with respect to fundus photographs or fluorescein angiography, and may also serve as useful end points for clinical trials [1–3]. In particular, OCT alterations at the inner retinal layers, involving especially ganglion cell layer and nerve fiber layer, have been described in diabetic patients without clinically detectable DR [4]. Moreover, the assessment of the geometric modification of the retinal vasculature in the early stage of DR may be correlated with the course of the disease [5–7]. In more detail, the baseline arteriolar and venular calibre save been associated with the long-term development of microvascular complications, including incident neuropathy, nephropathy and severe diabetic retinopathy [7]. Arteriolar and venular caliber alterations may also predict the visual acuity outcome in patients with diabetic macular edema (DME) treated with ranibizumab [8]. The availability of a practical classification of the different DME subtypes would remarkably improve the treatment algorithm. DME classification is typically based on the ETDRS grading, but its practical application has been limited. Several efforts have been made in an attempt to simplify the classification, correlating each specific form of DME with a specific treatment option. An easy DME classification based on biomicroscopic examination includes vasogenic, non-vasogenic, tractional, and mixed DME [9]. Vasogenic DME can be defined as macular thickening with visible vascular dilations (possibly associated with lipid exudates) detectable on biomicroscopy, whereas non-vasogenic DME is a macular thickening without visible vascular dilations (and possibly lipid

Table 1. Clinical Characteristics of Diabetic Macula Edema Subtypes

Vasogenic

Non-Vasogenic

Mixed

Tractional

Frequency

66% (126/192)

23% (44/192)

5% (11/192)

5% (11/192)

Mean BCVA (LogMAR)

0.42

0.47

0.46

0.64

Mean CRT

444

467

454

483

% 20 Hz), adaptation to static images, and non-linear summation of subunits in the receptive fields. In rats with retinal degeneration, the photovoltaic subretinal arrays restore visual acuity up to 64 μm/stripe – half of its normal level (30 μm/stripe), as measured by the cortical response to alternating gratings. If these results translate to human retina, such implants could restore visual acuity up to 20/250. With eye scan-

Camera

Image processor

Video goggles

Pulsed NIR illumination

Subretinal photodiode array

Fig. 1. Diagram of the prosthetic system including a camera, image processor, near-IR video goggles and subretinal photovoltaic array, converting pulsed light into electric current stimulating the nearby inner retinal neurons.

14


Abstracts

Fig. 2. Hexagonal photovoltaic array with 70 micrometer pixels,

each composed of 3 diodes connected between the disk electrode in the middle and circumferential return electrode. Array is placed on top of the retinal pigmented epithelium.

ning and perceptual learning, human patients might even cross the 20/200 threshold of legal blindness. Ease of implantation and tiling of these wireless arrays to cover a large visual field, combined with their low stimulation thresholds and high resolution opens the door to highly functional restoration of sight in patients blinded by retinal degeneration.

the human vision system. Furthermore the use of visual prostheses seems to increase patency in daily life tasks for retinal degeneration patients. Nevertheless the anatomical, physiological and technical circumstances are setting boundaries for prosthetic visual restoration. Various factors have been identified, that influence the success of retinal stimulation. This technology represents a major improvement in prior art, but is still subject to a host of limitations which are dependant on the manner in which one approaches the topic of visual prosthesis. These limitations pose new research challenges whose solutions are directly applicable to the well-being of blind individuals everywhere. We will outline and critically compare major current approaches to visual prosthesis, and in particular retinal prosthesis. There are fundamental limits to how dense a retinal electrode array can be made, and unless there is careful consideration of the stimulus parameters used, these limitations will prevent retinal prosthesis from achieving high-resolution restoration of vision for the patients. Like cochlear implants, visual implants will have to make do with far fewer channels of information than the biological system they replicate and. Like cochlear implants, visual implants will, with appropriate knowledge of how to stimulate the retina, be able to perform far better than the number of channels physically present. Based on our experience with different retinal-chip-technologies we want to review the limitations of visual functions by electrical retinal stimulation regarding to the different techniques and sites of stimulation.

References 1 Mathieson K, et al: Photovoltaic retinal prosthesis with high pixel density. Nature Photonics 2012;6(6):391–397. 2 Mandel Y, et al: Cortical responses elicited by photovoltaic subretinal prostheses exhibit similarities to visually evoked potentials. Nat Commun 2013;4:1980. 3 Boinagrov D, et al: Selectivity of direct and network-mediated stimulation of the retinal ganglion cells with epi-, sub- and intraretinal electrodes. J Neural Eng 2014;11(2):026008.

Main Session 5: Neovascular AMD

Limitations of Visual Prosthetics

Systemic Immunological Changes in Age-Related Macular Degeneration. Are they Relevant?

Gisbert Richard, Matthias Keserü

Torben Lykke Sørensen

Department of Ophthalmology, University Medical Center Hamburg-Eppendorf

Clinical Eye Research Unit, Department of Ophthalmology, Copenhagen University Hospital Roskilde and The Faculty of Health Sciences, University of Copenhagen, Denmark E-Mail [email protected]

Retinal Implant technology has improved over the last years, gaining advantages and possibilities in visual rehabilitation for patients with retinal degenerative diseases. Several study groups have already reported of successful promotion of visual sensations by electrical stimulation of Abstracts

Introduction: Due to its purely morphological name,

age-related macular degeneration (AMD), and distinct visual symptoms, AMD has always been considered an Ophthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

15

eye disease. However, recently, more researchers have posed the question to whether AMD is actually an eye manifestation of a systemic disease, or at least to some extent, an eye manifestation of systemic aging. AMD is clearly a disease of the elderly. Aging is a process characterized by an increase of degeneration, a degeneration that surpasses the body’s ability to regenerate, which in the context of AMD could be exemplified by the accumulation of drusen. This could be the result of defective aging ubiquitin-proteasome and chaperone systems [1, 2]. In addition, the structure of Bruchs membrane is diminished during aging challenging the integrity of the blood-retinal barrier exposing autophagy, apoptotic, necrosis or pyroptosis products to the systemic circulation [3]. This exposure could lead to the accumulation of inflammatory cells into the subretinal space leading to localized retinal inflammation and microglial activation. Both the accumulation of inflammatory cells into the subretinal space as well as the regulation of the subsequent resulting inflammation could in the individual patient depend on the ‘systemic immunological profile’ of the patient, but most likely there might be a particular profile which carries an increased risk of developing severe AMD. Methodological Challenges: We, and other groups, have tried to study these changes in the blood from patients with different stages of AMD, in order to investigate whether certain inflammatory markers on different subsets of leukocytes could be altered in patients with AMD. These studies require stringent setups, since the reliable analysis of fresh blood cells as well as soluble molecules in serum or plasma is dependent on time from acquisition of the sample to analysis. Since many life style factors (smoking, exercise), medications (corticosteroids, statins), and diseases (cancer, inflammatory disease) influence the immune system, it is important to have reliable data so that interpretation and categorization of the individual patients can be as homogenous as possible. AMD is both in the dry and exudative form, clinically heterogeneous, making it a challenge to stratify patients correctly. Also, subtle subretinal changes indicative of AMD can be missed in the control group, underscoring the importance of the availability of detailed retinal imaging both in the form of digital photography, but also OCT and autofluorescense imaging. An ICG should be performed on all patients since primarly polypoidal vasculopathy, but also maybe RAP lesions and retinal choroidal anastomosis could represent distinct immune-pathological entities. Focus of Studies: The immune system is complex, but fortunately, some clues to potentially players can 16


be found from genetic, histological, and animal studies as well as other disciplines of neurodegeneration and aging. Complement is the part of the immune system which has been most strongly implicated in AMD pathogenesis, hence studying complement factors in the blood seems relevant. Indeed regulatory complement molecules were found to be altered on different leukocyte subsets in patients with AMD, suggesting that more complex deficiencies, than complement factor H, could be present in patients with AMD [4]. In addition to complement, microglia activation has been a focus point, not only in neurodegenerative, but also in retinal disease. Regulators of microglia activity, includes among others, the CD200 molecule, and patients with AMD have lower levels of CD200 Ligand, suggestive of the patients be less able to down regulate microglia activity [5]. Whether microglia are beneficial or detrimental in AMD remains to be clarified? Chemokines and chemokine receptors have been intensively studied in murine models of AMD, therefore these molecules could be potential targets for studies [6]. Overall, both the adaptive and innate immune system could potentially be relevant in addition to aging. Conclusion: Studies of the systemic immune system poses exiting options and challenges, but there seems to be strong data supporting the notion that patients with AMD do have unique immunological features in there blood. Whether systemic changes in the blood from patients with AMD are primary or secondary effects remains to be elucidated on.

References 1 Campello L, Esteve-Rudd J, Cuenca N, Nieto J: The ubiquitin-proteasome system in retinal health and disease. Mol Neurobiol 2013;47:790– 810. 2 Ahn J, Piri N, Caprioli J, Munemasa Y, Kim SH, Kwong JM: Expression of heat shock transcription factors and heat shock protein 72 in rat retina after intravitreal injection of low dose N-methyl-D-aspartate. Neurosci Lett 2008. 3 Pauleikoff D, Harper CA, Marshall J, Bird AC: Aging changes in Bruch’s membrane. A histochemical and morphologic study. Ophthalmology 1990;97:171–178. 4 Singh A, Faber C, Falk M, Nissen MH, Hviid TV, Sørensen TL: Altered Expression of CD46 and CD59 on Leukocytes in Neovascular Age-Related Macular Degeneration. Am J Ophthalmol 2012;154(1):193–199. 5 Singh A, Falk MK, Hviid TVF, Sørensen TL: Increased Expression of CD200 on Circulating CD11b+Monocytes in Patients with Neovascular Age-Related Macular Degeneration. Ophthalmology 2013 Feb 12. pii: S0161-6420(12)01068-8. 6 Falk M, Singh S, Faber C, Nissen MH, Hviid TH, Sørensen TL: Dysregulation of CXCR3 in patients with neovascular age-related macular degeneration. Invest Ophthalmol Vis Sci 2014.

Abstracts

Long-Term Results of Vascular Endothelial Growth Factor Inhibitor Therapy for Neovascular Age-Related Macular Degeneration Frank G. Holz University of Bonn, Dept. of Ophthalmology, Bonn, Germany E-Mail [email protected]

Intravitreal anti-VEGF therapy has been demonstrated to provide favourable vision outcomes relative to previous therapies in patients with neovascular age-related macular degeneration (NVAMD). The initial vision gains can overall be maintained through 2 years either with fixed ir PRN reinjections following the initial loading phase. As AMD has a chronic progressive course it may require lifelong observation and therapy, i.e. the majority of patients requires longterm treatment beyond 2 years [1]. Most clinical studies too date have a limited review period of usually up to 2 years. Longer term prospective studies are obviously difficult to perform and costly. However, longterm outcomes with regard to efficacy and safety are of high relevance both to patients and health systems. Good initial functional outcomes may not be maintained over a longer period for a variety of reasons including undertreatment, suboptimal monitoring, suboptimal retreatment criteria, compliance, development of fibrosis/scarring or atrophy with subsequent loss of functional retina. Long-term safety and efficacy of multiple intravitreal ranibizumab injections was recently investigated in the HORIZON study, whereby ranibizumab was administered at the investigator’s discretion in patients NVAMD following treatment in patients who had completed the the MARINA, ANCHOR, or FOCUS trial [2]. The cumulative average numbers of injections received through years 1, 2, and 3 of HORIZON among the patients remaining in the study were 2.2, 4.2, and 4.3, respectively. For all ranibizumab treated-initial patients remaining in the study, the cumulative average numbers of injections received at years 1, 2, and 3 were 2.1, 4.4, and 4.7, respectively. With less frequent follow-up leading to less treatment, there was an incremental decline of the visual acuity (VA) gains achieved with monthly treatment. At month 48, the mean change in BCVA relative to the initial study baseline was 2.0 in the ranibizumab treated-initial group. Patient characteristics associated with ≥15-letter gains at month 48 included younger age and lower month 0 VA, and after 24 months of monthly treatment, better VA and smaller areas of lesion or (in controlled randomized group only) leakage. It was speculated that the switch Abstracts

from a strict monthly ranibizumab treatment regimen to less frequent investigator-determined PRN dosing was paralleled by signs of disease destabilization. Seven-years outcomes wereaddressed in the SEVENUP study, a multicenter, noninterventional cohort study [3]. The primary end point was percentage with best-corrected visual acuity (BCVA) of 20/70 or better; secondary outcomes included mean change in letter score compared with previous time points and anatomic results on fluorescein angiography, spectral-domain ocular coherence tomography (OCT), and fundus autofluorescence. At a mean of 7.3 years after entry into ANCHOR or MARINA, 37% of study eyes met the primary end point of 20/70 or better BCVA, with 23% achieving a BCVA of 20/40 or better. Thirty-seven percent of study eyes had BCVA of 20/200 or worse. Forty-three percent of study eyes had a stable or improved letter score (≥0-letter gain) compared with ANCHOR or MARINA baseline measurements, whereas 34% declined by 15 letters or more, with overall a mean decline of 8.6 letters. Active exudative disease was detected by spectral-domain OCT in 68% of study eyes, and 46% were receiving ongoing ocular anti-VEGF treatments. Macular atrophy was detected by FAF in 98% of eyes. The area of atrophy correlated significantly with poor visual outcome. Overal approximately 7 years after ranibizumab therapy, one third of patients demonstrated good visual outcomes, whereas another third had poor outcomes. Compared with baseline, almost half of eyes were stable, whereas one third declined by 15 letters or more. Even at this late stage in the therapeutic course, exudative AMD patients obviously remain at risk for substantial visual decline. The overall decline in mean ETDRS letter score during longterm review may reflect the inexorable nature of this disease even in the face of treatment, but other factors also may play a role. Low treatment frequencies may reflect the contemporaneous management during those years and may have contributed to the decline in mean visual acuity. Whether or not anti-VEGF therpy induces the development of atrophy or causes a faster progression of exisiting atrophic patches is yet unkown. Geographic atrophy is the natural disease process any is expected to occur irrespective of anti-VEGF therapy for a neovascular process during the disease course [4]. Recent analyses of the CATT-study indicated development of new atrophy in 18.3% of 1024 eyes trated with enti-VEGF therapy and found monthly treatments compared to PRN therapy to represent a high risk factor [5]. It may, therefore, be prudent to avoid overtreatment. Future studies need to imOphthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

17

plement adequate imaging modalities to detect and quantify areas of atrophy such as FAF and SD-OCT [6].

References 1 Wong TY, Chakravarthy U, Klein R, et al: The natural history and prognosis of neovascular age-related macular degeneration: a systematic review of the literature and meta-analysis. Ophthalmology 2008;115:116– 126. 2 Singer MA, Awh CC, Sadda S, Freeman WR, Antoszyk AN, Wong P, Tuomi L: HORIZON: an open-label extension trial of ranibizumab for choroidal neovascularization secondary to age-related macular degeneration. Ophthalmology 2012;119:1175–1183. 3 Rofagha S, Bhisitkul RB, Boyer DS, Sadda SR, Zhang K; SEVEN-UP Study Group: Seven-year outcomes in ranibizumab-treated patients in ANCHOR, MARINA, and HORIZON: a multicenter cohort study (SEVEN-UP). Ophthalmology 2013;120:2292–2299. 4 Holz FG, Schmitz-Valckenberg S, Fleckenstein M: Recent developments in the treatment of age-related macular degeneration. J Clin Invest 2014;124:1430–1438. 5 Grunwald JE, Daniel E, Huang J, Ying GS, Maguire MG, Toth CA, Jaffe GJ, Fine SL, Blodi B, Klein ML, Martin AA, Hagstrom SA, Martin DF; CATT Research Group: Risk of geographic atrophy in the comparison of age-related macular degeneration treatments trials. Ophthalmology 2014;121:150–161. 6 Holz FG, Strauss EC, Schmitz-Valckenberg S, van Lookeren Campagne M: Geographic Atrophy: Clinical Features and Potential Therapeutic Approaches. Ophthalmology 2014;121:1079–1091.

A Comparison of Ranibizumab and Bevacizumab for Neovascular Age-Related Macular Degeneration According to a Treat and Extend Protocol: 1-Year Results from the LUCAS Study Karina Berg for the LUCAS investigators Dept of Ophthalmology, Oslo University Hospital, Oslo, Norway

Background: Several randomized head-to-head clinical trials (CATT [1], IVAN [2], MANTA [3], GEFAL [4]) have confirmed similar efficacy between ranibizumab and bevacizumab, when treating patients with neovascular AMD monthly or as needed (pro re nata, PRN). The requirement for monthly monitoring with these treatment modalities is, however, difficult for older patients to maintain and also creates a heavy burden on the healthcare systems. Today, many practitioners use an individualized approach to anti-VEGF treatment. The ‘Treat and Extend’ regimen was proposed with the aim of extending visits and treatment intervals once the AMD disease was stabilized with monthly injections. With a ‘Treat and Extend’ protocol, the patients receive treatment at each visit re-

18


gardless of activity. If there is no sign of activity, the control and treatment interval is extended gradually, whereas if there are signs of recurrence, the interval is shortened. The aim of the Lucentis Compared to Avastin Study (LUCAS) was to compare the efficacy and safety of ranibizumab and bevacizumab when treating neovascular AMD, utilizing a ‘Treat and Extend’ protocol. LUCAS is a 2-year prospective randomized multicenter study. This is a presentation of the 1-year results. Patients and Methods: Between March 2009 and July 2012, 441 patients with neovascular AMD were included in a multicenter non-inferiority trial at 10 ophthalmological sites in Norway. The patients were randomized to receive intravitreal injections of either ranibizumab 0.5 mg or bevacizumab 1.25 mg in a 1:1 ratio, following a ‘Treat and Extend’ protocol. Eligibility criteria included age ≥50 years, previously untreated active neovascular AMD in one eye and best corrected visual acuity (BDVA) between 20/25 and 20/320. The diagnosis was confirmed by CVN leakage on fluorescein angiography (FA) and intraretinal and/or subretinal fluid as determined by optical coherence tomography (OCT). Pigment epithelial detachments (PED) with no associated intraretinal or subretinal edema as well as lesions comprising of more than 50% blood and/or fibrosis were excluded. The patients were examined and injected every 4 weeks until no signs of active AMD were found, as determined by OCT and biomicroscopic fundus examinations. If there were no signs of active disease, a new injection was given and the period to the next treatment was extended by 2 weeks at a time, up to a maximum of 12 weeks. Recurrent disease was defined as any fluid on OCT, new or persistent hemorrhage or dye leakage, or increase lesion size on FA. Decreased BCVA was not defined as a recurrence but FA was allowed to aid in retreatment decisions. If upon examination there was any sign of recurrence, the interval was shortened by 2 weeks at a time, until the disease was considered to be inactive. Interval extension was then restarted with the maximum final interval being 2 weeks less than the period when the recurrence was observed, with the aim of avoiding multiple recurrences.

References 1 Martin DF, Maguire MG, Fine SL, et al: Ranibizumab and Bevacizumab for Treatment of Neovascular Age-related Macular Degeneration: TwoYear Results. Ophthalmology 2012;119(7):1388–1398.

Abstracts

2 Chakravarthy U, Harding SP, Rogers CA, et al: Alternative treatments to inhibit VEGF in age-related choroidal neovascularisation: 2-year findings of the IVAN randomised controlled trial. Lancet 2013;382(9900): 1258–1267. 3 Krebs I, Schmetterer L, Boltz A, et al: A randomised double-masked trial comparing the visual outcome after treatment with ranibizumab or bevacizumab in patients with neovascular age-related macular degeneration. Br J Ophthalmol 2013;97(3):266–271. 4 Kodjikian L, Souied EH, Mimoun G, et al: Ranibizumab versus Bevacizumab for Neovascular Age-related Macular Degeneration: Results from the GEFAL Noninferiority Randomized Trial. Ophthalmology 2013; 120(11):2300–2309.

Fluid Management in the Treatment of Wet AMD: Is Zero Tolerance Necessary?

References 1 Martin DF, et al: Ranibizumab and bevacizumab for treatment of neovascular age-related macular degeneration: two-year results. Ophthalmology 2012;119(7):1388–1398. 2 Heier JS, et al: Intravitreal aflibercept (VEGF trap-eye) in wet age-related macular degeneration. Ophthalmology 2012;119(12):2537–2548.

Main Session 6: Uveal Melanoma. Current Conflicts & Controversy

Martin Zinkernagel Department of Ophthalmology, University of Bern, Switzerland E-Mail [email protected]

The popularity of nonfixed treatment regimens for exudative AMD has led to considerable debate over optimal criteria for retreatment. From large randomized clinical trials (RCT) like the CATT [1] and View studies [2] we know that even under study conditions strict retreatment criteria based on optical coherence tomography (OCT) are difficult to adhere to. For instance, the one-year data of the CATT study showed that in around 30% the retreatment criteria were not followed despite fluid on OCT. However, given the excellent results in regards to visual acuity in these studies the role of zero tolerance in relation to intra- or subretinal fluid has to be reconsidered. Furthermore, the experience from RCT in regards to fluid management is limited to two years whereas many patients in real life receive anti-VEGF therapy for many years. Based on our own data we will focus on the key retreatment criteria in routine practice based on spectral domain OCT. In particular, the advantages and disadvantages of a zero tolerance strategy in regards to intra- or subretinal fluid will be discussed for different treatment strategies such as treat and extend and fixed regimens. Furthermore the difficulties of implementing standardized retreatment criteria using a more relaxed regimen will be discussed.

Abstracts

New Developments in Uveal Melanoma M.J. Jager, P.A. van der Velden Department of Ophthalmology, LUMC, Leiden, The Netherlands E-Mail [email protected]

Recent developments in uveal melanoma (UM) especially involve the development of individualized treatment of metastases, as many different and effective treatments are already available for intraocular UM. One first has to determine whether the tumor is a UM, which can be decided on clinical findings, but also on genetic findings, as a mutation in GNAQ or GNA11 is found specifically in UM. We do not yet know at which stage a nevus develops these mutations, but these mutations are present in over 80% of UM [1]. A non-invasive technique to determine the presence of these mutations needs to be developed. Once the diagnosis of UM is made, one has to determine the chance that this patient will develop metastases, which depends on the nature and size of the primary tumor. Many different prognostic parameters have been identified. An ongoing discussion involves choosing the best technique to test tumor tissue. For large UM that undergo enucleation or tumors that are removed through local resection, enough material is available for histopathological analysis for the diagnosis UM, and for either successful chromosome analysis or analysing the RNA expression profile. Small suspicious tumors can be biopsied in situ, and one of the problems is to discern that one is really looking at a melanoma. For this, cytologic analysis or determination of the GNAQ/GNA11 status is essential. If it is indeed a melanoma (and not a metastasis of another malignancy, or a nevus), one may want to know whether it is a tumor with a high or a low chance of deOphthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

19

veloping metastases. This can be determined by looking at the chromosome 3 and 8q status [2], or by analysing the RNA profile [3]. In our laboratory, tumors that have lost one chromosome 3 usually have the class 2 gene expression profile. According to a study of Damato [2], a combination of chromosome status, tumor size and cell type helps to determine the risk of metastases more exactly than when one uses one marker only. However, a second point of discussion is the interaction of different parameters: a tumor may have lost one chromosome 3 or have the prognostically-bad RNA class 2 profile, but what determines the moment of clinical development of metastases? The TNM classification includes size as well as eg. ciliary body involvement, which is a characteristic of prognostically-bad tumors. It is likely that when a UM is discovered when it is already a large tumor, its metastases have had time to grow too, as has been proposed by T. Kivela. One would one day prefer to study the genetic changes in the tumor with an external imaging technique, which will help to know each patient’s chance of developing metastasis when they are included in clinical trials. When the diagnosis ‘UM with high metastatic potential’ has been made, the question comes up whether intensive screening is important. This has only recently become relevant, as till even now, no options have as yet been proven to work as preventive or curative treatment, with the exception of surgery for isolated metastases. Currently, drugs are being developed that have the potential to limit uveal melanoma cell growth in vitro and one can test these drugs in xenograft animal models [4]. The tumor’s sensitivity to a drug may depend on the GNAQ/ GNA11 mutation [5], or on the presence or absence of certain chromosome abnormalities, such as the loss of one chromosome 3. We do not yet know exactly which differences occur in the progression from intraocular tumor to metastasis, and whether characteristics of the primary tumor can predict the sensitivity to specific drugs in the metastases. Chromosome analysis has shown that primary tumors and metastases had similar chromosome abnormalities [6], but biochemical pathways have been shown to differ [7]. New treatments use specimens obtained from metastases to compare clinical effects with biochemical and genetic characteristics and the application of a combination of different drugs seems to be the most promising [8]. Hepatocyte growth factor (HGF) plays an important role in the homing of metastatic UM cells in the liver, through activation of the HGF receptor MET, while the MEK kinase-Erk1/2 pathway plays a role in driving cell division. Combining treatments that inhibit both pathways led to 20


a higher inhibition of cell proliferation than any of these treatments separately. Such drugs are now being tried in clinical trials. In addition to using drugs that interfere with biochemical pathways that regulate cell division and apoptosis, one may also attack the supply of oxygen by inhibiting the outgrowth of blood vessels in tumours [9]. Another option is immunotherapy. One may stimulate the immune system to attack UM cells by immunization with antigen-loaded dendritic or other antigen-presenting cells, or overcome immunosuppressive mechanisms by blocking the suppressive molecules. In the latter case, current therapies include anti-CTLA4 or anti-PD/ PDL1 monoclonal antibodies. In order for these therapies to work, one does need the presence of anti-melanoma T cell responses, so the outcome may be that one first needs to immunize the patient and then give blockers. Finally, as UM with a bad prognosis contain especially pro-angiogenic macrophages [10], different treatments that inhibit the function of macrophages or their effect (production of metalloproteinases) may delay outgrowth of metastases. Overall, this is an exciting time as we are now beginning to understand the molecular mechanisms that lead to uveal melanoma formation, and to the development of its metastases, and this may provide us with effective therapies to not only protect vision, but also help to preserve the life of the patient.

References 1 Van Raamsdonk CD, Griewank KG, Crosby MB, et al: Mutations in GNA11 in uveal melanoma. N Engl J Med 2010;363(23):2191–2199. Doi: 10.1056/NEJMoa1000584. 2 Damato B, Duke C, Coupland SE, et al: Cytogenetics of uveal melanoma: a 7-year clinical experience. Ophthalmol 2007;114(10):1925–1931. 3 Onken MD, Worley LA, Ehlers JP, Harbour JW: Gene expression profiling in uveal melanoma reveals two molecular classes and predicts metastatic death. Cancer Res 2004;64(20):7205–7209. 4 Nemati F, Sastre-Garau X, Laurent C, et al: Establishment and characterization of a panel of human uveal melanoma xenografts derived from primary and/or metastatic tumors. Clin Cancer Res 2010;16(8):2352– 2362. Doi: 1158/1078-0432.CCR-09-3066. 5 Chen X, Wu Q, Tan L, Porter D, Jager MJ, Emery C, Bastian BC: Combined PKC and MEK inhibition in uveal melanoma with GNAQ and GNA11 mutations. Oncogene 2013, Oct 21. Doi: 10.1038/onc.2013.418. 6 Trolet J, Hupe P, Huon I, et al: Genomic profiling and identification of high-risk uveal melanoma by array CGH analysis of primary tumors and liver metastases. Invest Ophthalmol Vis Sci 2009;50(6):2572–2580. Doi: 10.1167/iovs.08–2296. 7 Maat W, El Filali M, Dirks-Mulder A, Luyten GPM, Gruis NA, Desjardins L, Boender P, Jager MJ, Van der Velden PA: Episodic Src activation in uveal melanoma revealed by kinase activity profiling. Br J Cancer 2009;101:312–319.

Abstracts

8 Chattopadhyay C, Grimm EA, Woodman SE: Simultaneous inhibition of the HGF/MET and Erk1/2 pathways affect uveal melanoma cell growth and migration. PLoS One 2014;9(2):e83957. Doi: 10.1371/journal. pone.0083957. 9 El Filali M, van der Velden PA, Luyten GP, Jager MJ: Anti-angiogenic therapy in uveal melanoma. Dev Ophthalmol 2012;49:117–136. 10 Bronkhorst IH, Ly LV, Jordanova ES, Vrolijk J, Versluis M, Luyten GP, Jager MJ: Detection of M2 macrophages in uveal melanoma and relation with survival. Invest Ophthalmol Vis Sci 2011;52(2):643–650. Doi: 10.1167/iovs.10-5979.

Why Primary Endoresection Is Harmless? Jose Garcia-Arumi1,2,3, Zapata Victori Miguel2,3, Borja Corcostegui1 1Instituto de Microcirugia Ocular, 2Universidad Autónoma de Barcelona, 3Hospital Universitario Valle Hebrón, Barcelona, Spain

The validity of endoresection in the management of posterior uveal melanomas is highly debated because of concerns that surgical manipulation of the tumor might result in systemic and local dissemination of malignant cells. Ocular oncologists might consider performing endoresection as a primary intervention or as a salvage procedure whenever favorable response to other conventional primary or salvage procedures is deemed unlikely (1a,b). Indications include rapidly growing posterior melanomas whose thickness is greater than their base diameter to avoid morbidity associated with radiotherapy, local tumor recurrence following brachytherapy, transpupillary thermotherapy, or photocoagulation (fig. 1a, b). In this report, we present the extended follow-up results of primary endoresection for high posterior choroidal melanoma. Results: The study included 41 patients, 27 men and 14 women. Mean follow-up time was 102.5 months (range

a

b

20–180 months, SD 44.8). Twenty patients (48.8%) had endoresection alone, whereas 21 patients (51.2%) had endoresection and adjuvant brachytherapy. Mean preoperative BCVA was 20/100 (range hand movement to 20/20). Mean tumor thickness was 9.8 mm (range 7.7–13.5 mm, SD 1.7), whereas mean base diameter was 9.9 mm (range 5–15 mm, SD 2.8). The surgical technique varied according to the extent of retinal involvement. If the tumor had not yet invaded the retina, we performed 20-g vitrectomy with posterior hyaloid dissection, 120° anterior retinotomy, and endolaser photocoagulation using an 810-nm diode laser at 800 to 1,000 mW. Laser treatment was extended to 2 mm beyond the tumor margins. The melanoma was then removed with the vitrectomy probe using a bimanual technique. Intraocular pressure (IOP) was increased to 100 mm Hg for 5 minutes to prevent bleeding from choroidal vessels. Systemic hypotension was not induced during the procedure. Excision began at the apex of the tumor and carried down to the scleral bed. Diode endolaser (800–1,000 mW) was applied to the scleral bed to destroy residual tumor cells. The retina was reattached with perfluorocarbon liquid and air. Retinopexy was performed by applying endolaser photocoagulation to the retinotomy edges followed by fluid-air exchange and silicone oil-air exchange. If the tumor had already invaded the retina, diode laser was applied through the retina, and the tumor and the retina were removed together. Silicone oil was removed after 3 months. At the latest visit, 36/41 patients (87.8%) still retained the eye, and 5 patients had undergone 1 patient. Final BCVA ranged from no light perception to 20/20, mean 20/1625 as follows: ≤20/400 in 21 patients, 20/200 to 20/100 in 12 patients, and >20/100 in 8 patients. Chromosomal analysis was available in 21 cases. Chromosome 3 loss was detected in 5 cases. Poly-

c

Fig. 1. a Fundus optomap of a 55 years-old woman that presented a decrrease of visual acuity in her left eye secondary to a posterior choroidal melanoma thar had invaded the vitreous cavity. B-scan showed a thickness of 9.6 mm. b Fluorescein angiography of the posterior melanoma showing the double circulation of the tumor. c Fundus photograph after endoresection and plaque brachytherapy.

Abstracts


21

ploid chromosome 8 was presented in 3 cases. No patient had both abnormalities. Local tumor recurrence occurred in 5 patients (12.2%) in the group who had endoresection alone as the initial treatment and no recurrence was observed in the group with combined radiotherapy. Among 33 patients who completed 5 years’ follow-up (31 survivors, 1 death, and 1 lost to follow-up), two had melanoma metastasis to the liver (6%). Konstantinidis et al. [3] reported 7% of metastatic disease after surgery (fig. 1c), with a mean follow-up of 4 years, Karkhaneh et al. [4] reported one death caused by liver metastasis. Kertes et al. [5] reported three deaths due to metastasis. It is worthy of note that our local recurrence and metastasis rates are comparable to other studies on endoresection while bearing in mind that our series included patients with larger tumors in diameter and thickness, and a longer follow-up time. Conclusions: Endoresection remains a controversial technique, but in large uveal melanomas it may preserve the eye and vision, whereas other forms of conservative treatment are likely to cause severe ocular complications, with enucleation the only alternative treatment. Longterm follow-up of these patients did not show a higher risk of metastasis or local recurrence, and survival rates were similar to other techniques, although comparisons are difficult because of the unusual presentation of this type of melanoma. Further studies and longer follow-up are needed to establish the safety of this procedure.

References 1 Damato B, Groenewald C, McGalliard J, et al: Endoresection of choroidal melanoma. Br J Ophthalmol 1998;82:213–218. 2 Damato BE, Foulds WS: Surgical resection of choroidal melanoma. In: Ryan SJ, 3rd, ed. Retina. St Louis: Mosby, 2001, pp 762–772. 3 Konstantinidis L, Groenewald C, Coupland SE, Damato B: Br J Ophthalmol 2014;98(1):82–85. 4 Karkhaneh R, Chams H, Amoli FA, et al: Long-term surgical outcome of posterior choroidal melanoma treated by endoresection. Retina 2007; 27:908–914. 5 Kertes PJ, Johnson JC, Peyman GA: Internal resection of posterior uveal melanomas. Br J Ophthalmol 1998;82:1147–1153.

22


Uveal Melanoma. Tumours Are Best Treated with Brachytherapy Stefan Seregard St Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden E-Mail [email protected]

In the Western world, uveal melanoma is increasingly being treated with radiotherapy rather than enucleation of the eye [1]. By far the most common type of radiotherapy is episcleral brachytherapy using an applicator with one of a range of radionuclides. This is the only eye-preserving option shown not to compromise the prognosis of the patient compared to that following enucleation of the eye [2]. The by far most popular radionuclides are ruthenium 106 in Europe and iodine 125 in the United States. Many centres have access to both radionuclides allowing treatment to be optimized to the tumour thickness. Other radionuclides less frequently in use include palladium 103 and strontium 90. The source of radiation may be integrated into the plaque (e.g. ruthenium 106) or provided in small seeds that can be fixed in slots in standardized inserts (e.g. iodine 125). Most often a standard dose of 80–100 Gy to the tumour apex is prescribed for treatment of uveal melanoma. Typically, this dose requires the radioactive plaque to be fixed to the sclera for some 3–6 days. Alternatively, some centres use a minimum dose to the sclera. Most centres limit radiation to the sclera to 1,000 Gy or sometimes 1,500 Gy. Adequate dosimetry is important and close collaboration with radiation physicists and/or radiation oncologists is advised. The reported dose rate ranges widely, but there are no data to suggest that this significantly affects ocular outcome including the risk for secondary enucleation. Brachytherapy is subject to a number of national and local regulating bodies resulting in different safety requirements in different countries. Radiation exposure to the patient away from the treated eye, nursing staff and surgeon, however, is minimal and may, if needed, be monitored. Proper plaque positioning is critical for outcome. Typically, the radioactive plaque is fixed to the sclera covering the tumour ensuring a 2 mm safety margin around the tumour. Although most centres rely on transillumination to visualize the portion of sclera that needs to be included in the field of radiation, some centres use per-operative ultrasonography to improve accuracy [3]. This and other techniques ensure that the radioactive plaque can often be positioned within 1 mm of the planned location, but the learning curve is steep and it is advised that plaque Abstracts

radiotherapy is best performed in a tertiary referral setting [4]. Radiation retinopathy is the most frequent significant side effect occurring in up to half of patients. The risk for retinopathy is related to the dose to the retina, area of retina irradiated and choice of radionuclide. Radiation retinopathy is also more likely to occur in patients with diabetic retinopathy. Radiation-related complications can be minimized using techniques like eccentric plaque fixation, adjunctive transpupillary thermotherapy, and intravitreal injections of pharmacologic agents [5, 6]. Other types of collateral damage following brachytherapy for uveal melanoma include cataract, choroidal atrophy, neovascular glaucoma, optic neuropathy and, rarely, scleral melting. Successful episcleral brachytherapy for uveal melanoma typically leaves a pigmented, often slightly protruding, tumour scar. This needs to be periodically monitored for tumour recurrence for many years and quite possibly for life. Serial fundus photographs and ultrasonography are helpful in detecting local tumour recurrence following brachytherapy. The risk for local tumour recurrence depends on a number of factors including location and size of tumour, choice of radionuclide and use of adjunctive transpupillary thermotherapy. In selected groups of patients, local failure rate after episcleral brachytherapy for uveal melanoma may be less than 5% [7]. Retreatment is often possible, but secondary enucleation following failure of local control or because of significant side effects may occasionally be required. Although episcleral brachytherapy involves surgery for plaque fixation and removal, this is often required for fixation of markers before other proton beam radiotherapy is performed. Importantly, plaque radiotherapy for uveal melanoma is comparatively easily accessible and does not require very expensive and complicated devices like cyclotrons. Brachytherapy can therefore be performed in a more financially constrained setting, arguably providing a major cause for the frequent use. Cost will be significantly lower than for other radiation techniques like proton beam radiotherapy, stereotactic radiotherapy, gamma knife radiotherapy of cyber knife radiotherapy. This is particularly relevant when ruthenium 106 is used. The long half-life of this radionuclide allows for many treatments during its practical period of use of one year or more. Limitations of brachytherapy for uveal melanoma include very large tumours or, possibly, tumours with significant juxtapapillary or circumpapillary involvement.

However, such tumours are notoriously difficult to treat with any other eye-preserving options without causing extensive visual damage and ocular morbidity. Many of these tumours may therefore best be managed by enucleation of the eye.

Abstracts


References 1 Singh AD, Turell ME, Topham AK: Uveal melanoma: trends in incidence, treatment, and survival. Ophthalmology 2013;118:1881–1885. 2 Collaborative Ocular Melanoma Study Group: The COMS randomized trial of iodine 125 brachytherapy for choroidal melanoma: V. Twelveyear mortality rates and prognostic factors: COMS report No. 28. Arch Ophthalmol 2006;124:1684–1693. 3 Chang MY, Kamrava M, Demanes DJ, Leu M, Agazaryan N, Lamb J, Moral JN, Almanzor R, McCannel TA: Intraoperative ultrasonographyguided positioning of iodine 125 plaque brachytherapy in the treatment of choroidal melanoma. Ophthalmology 2012;1119:1073–1077. 4 Shah NV, Houston SK, Murray TG, Markoe AM: Evaluation of the surgical learning curve for I-125 episcleral plaque placement for the treatment of posterior uveal melanoma: a two decade review. Clin Ophthalmol 2012;6:447–452. 5 Seregard S, Pelayes DE, Singh AD: Radiation therapy: posterior segment complications. Dev Ophthalmol 2013;52:114–123. 6 Russo A, Laguardia M, Damato B: Eccentric ruthenium plaque radiotherapy of posterior choroidal melanoma. Graefes Arch Clin Exp Ophthalmol 2012;250:1533–1540. 7 Damato B, Patel I, Campbell IR, Mayles HM, Errington RD: Local tumor control after 106Ru brachytherapy of choroidal melanoma. Int J Radiat Oncol Biol Phys 2005;63:385–391.

Uveal Melanoma: Screening Is Useless Dan S. Gombos Section of Ophthalmology, Department of Head and Neck Surgery, MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 1445, Houston Texas USA 77303-4009 E-Mail [email protected]

It is generally accepted medical practice to perform systemic assessment of patients newly diagnosed with uveal melanoma. The propensity of these lesions to spread to the pulmonary or hepatic systems justifies baseline imaging. Following definitive therapy of the primary neoplasm there remains considerable debate as to the merits of routine systemic surveillance for distant metastatic disease. The Collaborative Ocular Melanoma Study recommended chest x-rays and biochemical liver markers for routine screening [1]. Nearly all experts agree that these tests have limited sensitivity or benefit. Most clinicians have abandoned this approach. Twice yearly hepatic echography is advocated by numerous European centers 23

as a screening method [2]. While cost effective, the modality is highly operator dependent with a tendency toward false positive errors. These can lead to additional expensive and unnecessary testing. In addition hepatic echography is generally limited to patients with lower body mass indices (BMI), as body fat within the midsection reduces the test’s sensitivity. An increased rate of obesity in the developed world has reduced the efficacy of this modality in most countries. In North American tertiary cancer centers the standard imaging technique to screen melanoma patients is either a CT scan with contrast or an MRI, some advocate PET-CT. Concern and caution has been raised with regard to recurrent CT and PET-CT scans for surveillance due to the accumulated lifetime risk of radiation exposure [3]. MRI scans are cost prohibitive in most centers and many third party insurance companies will not reimburse for this modality. Irrespective, routine surveillance has been rejected by many experts primarily due to the lack of any objective data that early detection alters the overall survival of patients with distant spread. While patients may appear to live longer (having undergone earlier diagnosis) many attribute this to lead time bias [4]. In fact while the most recent published studies using selumetinib in patients with metastatic uveal melanoma improved progression free survival, overall survival did not change [5]. In conclusion given that we currently do not have any therapy proven to improve overall survival at any stage it seems that routine screening may not only be a poor use of limited resources but falsely impart upon our patients the impression that early detection will improve their prognosis. There is simply no definitive data that justifies routine surveillance as it relates to patient survival; for this reason uveal melanoma screening should be considered useless.

References 1 The Collaborative Ocular Melanoma Study Group: Design and methods of a clinical trial for a rare condition: the Collaborative Ocular Melanoma Study. COMS report no. 3. Contr Clin Trials 1993;14:362–391. 2 Gombos DS, Van Quill KV, UusitaloM, O’Brien JM: Geographic disparities in diagnostic screening for metastatic uveal melanoma. Ophthalmology 2004;111(12):2254–2258. 3 Wen JC, Sai V, Straatsma BR, McCannel TA: Radiation-related cancer risk associated with surveillance imaging for metastasis from choroidal melanoma. JAMA Ophthalmol 2013;131(1):56–61. 4 Augsburger JJ, Correa ZM, Shaikh AH: Effectiveness of treatments for metastatic uveal melanoma. Am J Ophthalmol 2009;148:119–127.

24


5 Carvajal RD, Sosman JA, Quevedo J, et al: Effect of Selumetinib vs Chemotherapy on Progression-Free Survival in Uveal Melanoma: A Randomized Clinical Trial. JAMA 2014;311(23):2397–2405.

Main Session 7: Imaging

Quantitative Autofluorescence Imaging François C. Delori1, Tobias Duncker2, Janet R. Sparrow2 1Mass

Eye and Ear Infirmary, Harvard Medical School, Boston, Mass., 2Ophthalmology, Columbia University, New York, NY, USA E-Mail francois_delori@ meei.harvard.edu

Given the widespread use of fundus autofluorescence (AF) imaging, there is need for reliable determination of AF levels at specific retinal locations. We have developed a technique to perform standardized quantitative measurements of fundus AF in images obtained by scanning laser ophthalmoscope [1]. The basic concept of the methodology is to normalize fundus AF to the fluorescence measured within a standard mounted in the imaging device. This normalization allows compensation for the effect of variation in laser power and detector gain. Quantified AF (qAF) facilitates longitudinal studies, comparison amongst patients, and comparison of AF levels obtained with different imaging devices. In healthy subjects, we found that the AF levels increased monotonically with age reflecting continuous accumulation of RPE lipofuscin [2]. The rate of accumulation was highest for whites and significantly lower for blacks, and Asians. qAF levels were higher in females as compared to males and tended to be higher in subjects that had smoked. In Best vitelliform macular dystrophy, an important issue in the field has been whether there is a generalized increase in lipofuscin throughout the retina in addition to the highly elevated AF in the vitelliform lesion. In a study of 16 patients ranging in age from 6 to 62 years [3], we found that qAF outside the central lesion was not elevated and was always within the 95% confidence interval of the healthy population. In recessive Stargardt disease (STGD1), mutations in the ABCA4 gene are known to cause increased levels of lipofuscin. Accordingly, in a study of 42 patients with confirmed ABCA4 mutations and ranging in age from 7 Abstracts

to 52 year [4], we found that the vast majority of patients had qAF8 levels above the 95% confidence interval of healthy subjects. In young patients, qAF levels were higher when associated with mutations (e.g. L541P/A1038v and R1640W) conferring severe disease. Conversely, patients carrying the G1916E mutation (often associated with a milder disease) had lower qAF8 compared to other patients, even in the presence of a second allele associated with severe disease. The qAF method was able to elucidate phenotypic variation between patients, even when qualitative differences in fundus AF images were not evident. qAF promises to be a valuable outcome measure in clinical trials involving STGD1 and other retinal degenerations treated by drugs designed to reduce the accumulation of lipofuscin.

References 1 Delori F, et al: Quantitative measurements of autofluorescence with the scanning laser ophthalmoscope. Invest Ophthalmol Vis Sci 2011;52(13): 9379–9390. 2 Delori FC, et al: In vivo fluorescence of the ocular fundus exhibits retinal pigment epithelium lipofuscin characteristics. Invest Ophthalmol Vis Sci 1995;36:718–729. 3 Duncker T, et al: Quantitative fundus autofluorescence and optical coherence tomography in best vitelliform macular dystrophy. Invest Ophthalmol Vis Sci 2014;55(3):1471–1482. 4 Burke TR, et al: Quantitative Fundus Autofluorescence in Recessive Stargardt Disease. Invest Ophthalmol Vis Sci 2014.

A vitreoretinal disease expert panel was convened to develop an optical coherence tomography (OCT)-based anatomic classification system for diseases of the vitreomacular interface (VMI) to support systematic diagnosis and management by creating a clinically applicable system that is predictive of surgical outcomes and useful for the execution and analysis of clinical studies. Results: Vitreomacular traction (VMT) is characterized by anomalous PVD accompanied by anatomic distortion of the fovea, which may include pseudocysts, schisis, cystoid macular edema, and subretinal fluid. VMT can be subclassified by the diameter of vitreous attachment to the macular surface as measured by OCT, with attachment of ≤1,500 μm defined as focal and >1,500 μm as broad. When associated with other macular disease, VMT is classified as ‘concurrent.’ Full-thickness macular hole (FTMH) is defined as a foveal lesion with interruption of all retinal layers from the internal limiting membrane (ILM) to the retinal pigment epithelium (RPE). FTMH is primary if caused by vitreous traction or secondary if directly due to pathology other than VMT. FTMH is subclassified by size of the hole as determined by OCT and the presence or absence of VMT. Summary: OCT allows detailed imaging of the retinal layering. A new classification has been published to describe tractions diseases of the vitreomacular interface.

References

Imaging and Disease Classification of the Vitreomacular Interface

– –

Peter Stalmans Dept. Ophthalmology UZLeuven, Leuven, Belgium

– –

Introduction: Our understanding of the vitreo-retinal

interface (VRI) has been transformed with the advent of optical coherence tomography (OCT) imaging. OCT allows noninvasive capture of high-resolution images with detailed examination of vitreo-retinal anatomy (fig. 1). Advances in VRI imaging technology using newer spectral-domain OCT have further improved the efficiency and accuracy with which pathologic VRI conditions are identified and treated. Purpose: The developments in OCT imaging and the advent of pharmacological vitreolysis have the driven the need for a new classification of tractional diseases of the vitreomacular interface to replace the current Gass classification. Abstracts

–

Gass JD: Reappraisal of biomicroscopic classification of stages of development of a macular hole. Am J Ophthalmol 1995;119:752–759. Gass JD: Idiopathic senile macular hole: its early stages and pathogenesis. Arch Ophthalmol 1988;106:629–639. Stalmans P, Benz MS, Gandorfer A, et al; MIVI-TRUST Study Group: Enzymatic vitreolysis with ocriplasmin for vitreomacular traction and macular holes. N Engl J Med 2012;367:606–615. Duker JS, Kaiser PK, Binder S, de Smet MD, Gaudric A, Reichel E, Sadda SR, Sebag J, Spaide RF, Stalmans P: The International Vitreomacular Traction Study Group classification of vitreomacular adhesion, traction, and macular hole. Ophthalmology 2013;120(12):2611–2619. Stalmans P, Duker JS, Kaiser PK, Heier JS, Dugel PU, Gandorfer A, Sebag J, Haller JA: Oct-based interpretation of the vitreomacular interface and indications for pharmacologic vitreolysis. Retina 2013;33(10):2003– 2011.


25

Fig. 1. Geographic atrophic due to AMD: atrophic areas appear as sharply demarcated areas with de-

pigmentation on fundus photograph (left). At the corresponding fundus autofluorescence image (right), atrophic patches are clearly delineated by decreased intensity and high-contrast to non-atrophic retina. Surrounding atrophy, in the junctional zone of atrophy, levels of marked FAF intensity are observed which are invisible on fundus photography.

Imaging Intrinsic Signals in Dry Age-Related Macular Degeneration Frank G. Holz University of Bonn, Dept. of Ophthalmology, Bonn, Germany E-Mail [email protected]

Fundus autofluorescence (FAF) imaging allows for topographic mapping of lipofuscin (LF) distribution in the retinal pigment epithelial (RPE) cell monolayer as well as of other fluorophores that may occur with disease in the outer retina and the sub-neurosensory space [1]. It provides additional information not obtainable with other imaging techniques such as fundus photography, fluorescein angiography, or OCT. Excessive accumulation of LF granules in the lysosomal compartment of RPE cells represents a common downstream pathogenetic pathway in various hereditary and complex retinal diseases. Nearinfrared fundus autofluorescence (NIA) images can also be obtained in vivo using the indocyanine-green angiography mode. It has been suggested that the NIA-signal is largely melanin derived [2]. Recording of FAF images is non-invasive and requires relatively little time. The intensity of naturally occurring fluorescence of the ocular fundus is about two orders of magnitude lower than the background of a fluorescein angiogram at the most intense part of the dye transit. 26


Both scanning laser ophthalmoscopy imaging and fundus camera photography have been used in the clinical setting for the acquisition of fundus autofluorescence. Confocal scanning laser ophthalmoscopy (cSLO) optimally addresses the limitations of low intensity of the autofluorescence signal and the interference of the crystalline lens. Early manifestation of AMD include focal hypo- and hyperpigmentations at the level of the RPE as well as drusen with extracellular material accumulating in the inner aspects of Bruch’s membrane [3]. Drusen visible on fundus photography are not necessarily correlated with notable FAF changes and areas of increased FAF may or may not correspond with areas of hyperpigmentation or soft or hard drusen. Overall, larger drusen are associated more frequently with notable FAF abnormalities than smaller ones, with the exception of basal laminar drusen. Crystalline drusen are typically show a corresponding decreased FAF signal. Increased FAF intensities next to drusen funduscopically corresponding to focal hyperpigmentation and pigment figures have been explained by the presence of melano-LF or changes in the metabolic activity of the RPE. Areas of hypopigmentation on fundus photographs tend to be associated with a corresponding decreased FAF signal, suggesting the absence of RPE cells or degenerated RPE cells with reduced content of LF granules. Abstracts

FAF imaging allows better than CFP to identify reticular pseudodrusen, revealing a unique reticular FAF pattern with multiple small rounded or elongated areas of decreased FAF surrounded by areas with brighter intensities [4]. The exact morphological correlate of this distinct pattern is controversial. The spectrum of FAF findings in patients with early AMD was classified by an international expert group [5]. Pooling data from several retinal centres, a system with eight different FAF pattern was developed, including normal, minimal change, focal increased, patchy, linear, lacelike, reticular, and speckled pattern. This classification demonstrates the relatively poor correlation between visible alterations on fundus photography and notable FAF changes. Based on these results, it was speculated that FAF findings in early AMD may indicate more widespread abnormalities and diseased areas. FAF imaging has proven particularly useful in geographic atrophy (GA) secondary to AMD. Due to the absence of RPE and, thus, intrinsic LF fluorophores, atrophic areas in GA patients exhibit a severely reduced signal [1, 3, 6, 7] (fig. 1). The high-contrast difference between atrophy and non-atrophic retina permits accurate delineation of lesion boundaries and quantification of uni- or multifocal atrophic areas on FAF images using customized image analysis software. This allows for non-invasive monitoring of atrophy progression over time [7], and, therefore assessment of therapeutic effects of novel agents aiming at slowing GA enlargement over time. An additional important finding with FAF imaging in GA patients is the visualization of abnormal FAF distribution in the junctional and perilesional zone surrounding atrophic patches. Distinct FAF patterns correlate with enlargement rates of GA patches over time [8]. Such highrisk markers shed light on pathophysiological mechanisms and are relevant for the design of interventional trials to reduce sample size and study period in an overall slow progressing disease. Atrophy in the context of AMD is a dynamic process with gradual enlargement of atrophic areas over time. Initial natural history studies on atrophy progression in GA patients using FAF imaging demonstrated the occurrence of new atrophic patches and the spread of pre-existing atrophy in areas with abnormally high levels of FAF at baseline [9]. The FAM-study identified large variability of atrophy enlargement between patients, which was neither explained by baseline atrophy or by any other risk factor in association with AMD including smoking, lens status, or family history. These results have subsequently been confirmed in another large-scale natural history study

(GAP-study). The findings underscore the importance of abnormal FAF intensities around atrophy in patients with GA due to AMD [10].

Abstracts


References 1 Holz FG, Schmitz-Valckenberg S, Spaide RF, Bird AC: Atlas of fundus autofluorescence imaging. Berlin, Heidelberg, New York: Springer; 2007. 2 Keilhauer CN, Delori FC: Near-infrared autofluorescence imaging of the fundus: visualization of ocular melanin. Invest Ophthalmol Vis Sci 2006;47:3556–3564. 3 Schmitz-Valckenberg S, Fleckenstein M, Scholl HP, Holz FG: Fundus autofluorescence and progression of age-related macular degeneration. Surv Ophthalmol 2009;54:96–117. 4 Schmitz-Valckenberg S, Steinberg JS, Fleckenstein M, Visvalingam S, Brinkmann CK, Holz FG: Combined confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography imaging of reticular drusen associated with age-related macular degeneration. Ophthalmology 2010;117:1169–1176. 5 Fleckenstein M, Charbel Issa P, Helb HM, et al: High-resolution spectral domain-OCT imaging in geographic atrophy associated with age-related macular degeneration. Invest Ophthalmol Vis Sci 2008;49:4137–4144. 6 Bindewald A, Bird AC, Dandekar SS, et al: Classification of fundus autofluorescence patterns in early age-related macular disease. Invest Ophthalmol Vis Sci 2005;46:3309–3314. 7 Schmitz-Valckenberg S, Brinkmann CK, Alten F, et al: Semiautomated image processing method for identification and quantification of geographic atrophy in age-related macular degeneration. Invest Ophthalmol Vis Sci 2011;52:7640–7646. 8 Holz FG, Bindewald-Wittich A, Fleckenstein M, Dreyhaupt J, Scholl HP, Schmitz-Valckenberg S: Progression of geographic atrophy and impact of fundus autofluorescence patterns in age-related macular degeneration. Am J Ophthalmol 2007;143:463–472. 9 Holz FG, Strauss EC, Schmitz-Valckenberg S, van Lookeren Campagne M: Geographic Atrophy: Clinical Features and Potential Therapeutic Approaches. Ophthalmology 2014;121:1079–1091. 10 Holz FG, Schmitz-Valckenberg S, Fleckenstein M: Recent developments in the treatment of age-related macular degeneration. J Clin Invest 2014;124:1430–1438.

Autofluorescence Lifetime Measurements of the Retina Sebastian Wolf, Martin Zinkernagel Dep. Ophthalmology, University Hospital, Inselspital, University Bern, Bern, Switzerland

Purpose: Fluorescence lifetime measurement is a new method that enables us to better characterize different fluorphores in the retina. The fluorescence of organic molecules can be characterized by the absorption and emission spectrum, the fluorescence intensity and by the fluorescence lifetime or decay time. The new Fluorescence Lifetime Imaging Ophthalmoscope (FLIO) is based on a Heidelberg Engineering Spectralis® system and allows measurements of fluorescence lifetimes in vivo in

27

the retina. First results of fluorescence lifetime measurements in healthy subjects and in patients with AMD will be presented. Methods: The novel fluorescence lifetime ophthalmoscope is based on a Heidelberg Engineering Spectralis® system. The basic functions of the Spectralis are preserved. For fluorescence excitation, an 473 nm ps (picosecond)-laser at 80 MHz repetition rate, is coupled to the camera head. The laser beam is raster scanned across the retina by the Spectralis scanning system. Emitted fluorescence light is descanned and confocally filtered using a 100 μm multi-mode optical detection fiber. The time-resolved autofluorescence is detected by highly sensitive hybrid photon-counting detectors and registered in time-correlated single-photon counting (TCSPC). The fluorescence light is spectrally separated in two detection channels from 498–560 nm and 560–720 nm. Each detected photon is thus characterized by its time in the laser periode, its coordinates in the scanning area, and its wavelength. The recording process builds up a photon distribution over these parameters from which a fluorescence lifetime map of the fundus is approximated using a multi-exponential fitting procedure. Results: Fluorescence lifetime images of healthy subjects show typically shortest fluorescence lifetimes in the macular area. The optic nerve head as well as retinal vessels show the longest lifetimes. Fluorescence lifetimes between both eyes of the same subject are well correlated. We have found an increase of fluorescence lifetimes with increasing age. Patients with dry age-related macular degeneration (geographic atrophy) show marked increase fluorescence lifetimes within the atrophic areas. Conclusions: The new Fluorescence Lifetime Imaging Ophthalmoscope (FLIO) is a new promising imaging technique that may allow to assess the metabolic status of the retina and the RPE. This technique may offer new insights into the normal and pathologic ageing process of the retina.

28


Main Session 8: PVR & Innovation in Retinal Detachment Surgery

Genetics of PVR and RD J. Carlos Pastor1,2, S. Pastor-Idoate1,3, I. Rodríguez-Hernandez4,5, J. Rojas1,6, I. Fernandez1,7, L. Gonzalez-Buendia1,2, S. di Lauro1,2, R. Gonzalez-Sarmiento4,5 1Instituto

de Oftalmobiología Aplicada (IOBA), University of Valladolid, Valladolid, Spain; 2Department of Ophthalmology, Hospital Clínico Universitario de Valladolid, Valladolid, Spain; 3Manchester Royal Eye Hospital, Manchester, UK; 4Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain; 5Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Investigación Biomédica de Salamanca (IBSAL), University of Salamanca, Salamanca, Spain; 6Department of Ophthalmology, Universidad Austral, Buenos Aires, Argentina; 7CIBER-BBN, Instituto de Salud Carlos III, Valladolid, Spain E-Mail [email protected]

Proliferative vitreoretinopathy (PVR) is still the major cause of failure in retinal detachment (RD) surgery [1], affecting 5% to 10% of RD and accounting for approximately 75% of all primary failures after RD surgery [1, 2]. PVR is a complex process, involving not only ischemic tissue damage (after the retina is detached external layers become ischemic), but also intraocular inflammation and proliferation of several types of retinal cells mainly retinal pigment epithelial (RPE) and glial cells (Müller cells and astrocytes). PVR was identified as an independent clinical entity in 1983 and since then, few real advances have been made in its prophylaxis, medical management and anatomical and functional results. The identification of intraretinal changes developed in the most severe forms of PVR and the role of glial cells in this response could be considered as a crucial point in the understanding of the pathogenesis of this disease. Currently, it is considered a multifactorial disease [1, 2], in which there is an interaction between environmental factor (clinical variables) and the genetic profile of each subject [3–5]. Despite the fact that the exact mechanisms responsible of PVR are not completely understood, it is widely accepted that inflammation plays an important role in its pathogenesis [1, 2, 5, 6]. In this sense, this interaction determines the susceptibility of any subject to develop this complication once the RD is established. Abstracts

The contribution of the genetic component to PVR could be considered another key point. In 2005 and after a retrospective study trying to identify clinical risk factors related to PVR development [7], we hypothesized that besides these factors a genetic predisposition should be necessary in order to explain most of the cases. Thus in 2006 we started a collaborative, multicentric case-control study, named Retina 4, which suggested the association between inflammation genes and PVR development [4– 6, 8]. These findings have been confirmed in a large European population study [9] and have also contributed to a better understanding of this disease. At present, most authors recognize this genetic contribution, which is opening new possibilities for treating PVR. This fact is crucial because after more than 30 years trying to inhibiting cell proliferation as the main mechanism responsible of this RD complication, the failure of all of the treatments indicates that the understanding of its pathogenesis was not adequate. Therefore some different approaches such as the inhibition of TNF-alpha or some other factors could result in a clear benefit [5]. In addition, we have recently identified some association between PVR and genes involved in cell death mechanisms after RD, such as apoptosis and other cell death pathways, i.e. programmed necrosis which plays an important role in photoreceptor degeneration and subsequent visual loss after RD and PVR [8, 10]. Reattachment of the retina is now achieved in up to 90% of cases with single or multiple interventions. Now our challenge is to recover visual function. In a large prospective series, named Retina 1, and already published by our group we found that only 44% of patients with noncomplicated RD achieved a visual acuity of ≥20/40 at 3 months of follow up after successful surgery, and 22.6% of them obtained less than 20/100. Therefore there is still a large way for improvement. And, coming back to the new ideas on pathogenesis of this disease, it has been reported that levels of p53 (a protein involved in regulating apoptosis) expression could be a checkpoint in the development of RD and PVR, thus preventing the decrease of p53 levels in the vitreous by using inhibitors of mdm2, seems to be a promising prophylactic approach as a in experimental RD and PVR. All this new information based on genetic studies opens a real possibility of identifying more accurately those patients with a high risk of developing PVR and thus the justification of using adjuvant medical treatments in addition to the surgery. In this way, we have developed some predictive models of PVR [4]. Following Abstracts

their validation, one of them has demonstrated the utility of analyzing clinical and genetic factors all together. Finally the emphasis made on the death mechanisms involved in photoreceptor damage after RD, also present in PVR, could be a key factor for developing new strategies targeted at improving the functional results of patients affected by both diseases, a current challenge for retinologists.

References 1 Pastor JC: Proliferative Vitreoretinopathy: An Overview (major Review). Surv Ophthalmol 1998;43:3–18. 2 Pastor JC, Rodríguez de la Rúa E, Martín F: Proliferative vitreoretinopathy: risk factors and pathobiology. Prog Retin Eye Res 2002;21:127–144. 3 Sanabria MR, Pastor JC, Garrote JA, Tellería JJ, Yugueros MI: Cytokine gene polymorphisms in retinal detachment patients with and without proliferative vitreoretinopathy: a preliminary study. Acta Ophthalmol Scan 2006;84:309–313. 4 Rojas MJ, Fernández I, Pastor JC, Manzanas L, Rodríguez de la Rúa E, Sanabria RM, Brion M, Sobrino B, Giraldo A, García MT, Carracedo A: Development of predictive models of proliferative vitreoretinopathy based on genetic variables. The Retina 4 project. Invest Ophthalmol Vis Sci 2009;50:2384–2390. 5 Rojas J, Fernandez I, Pastor JC, Garcia-Gutierrez MT, Sanabria MR, Brion M, Coco RM, Ruiz Moreno JM, Garcia Arumi J, Elizalde J, RuizMiguel M, Gallardo JM, Corrales RM, Sánchez D, Carracedo A: A Strong Association in the TNF Locus with Proliferative Vitreoretinopathy. The Retina 4 Project. Ophthalmology 2010;117:2417–2423. 6 Delyfer MN, Raffelsberger W, Mercier D, et al: Transcriptomic analysis of human retinal detachment reveals both inflammatory response and photoreceptor death. PloS one 2011;6:e28791. 7 Rodriguez de la Rua E, Pastor JC, Aragon J, Mayo-Iscar A, Martínez V, Garcia Arumí J, Giraldo A, Sanabria-Ruiz Colmenares RM, Miranda I: Interaction between surgical procedure for repairing retinal detachment and clinical risk factors for proliferative vitreoretinopathy. Curr Eye Res 2005;30:147–153. 8 Pastor-Idoate S, Rodríguez Hernandez I, Rojas J, Fernandez I, García Gutierrez MT, Ruiz Moreno JM, Rocha Sousa A, Ramkissoon Y, Harsum S, MacLaren RE, Charteris D, Van Meurs J, Gonzalez Sarmiento R, Pastor JC: The p53 codon 72 polymorphism (rs1042522) is associated with proliferative vtreoretinopaty. The Retina 4 project. Ophthalmology 2013;120:623–628. 9 Rojas J, Pastor JC, MacLaren R, et al: A genetic case-control study confirms the implication of SMAD7 and TNF locus in the development of proliferative vitreoretinopathy. Invest Ophthalmol Vis Sci 2013;54: 1665–1678. 10 Pastor-Idoate S, Rodriguez-Hernandez I, Rojas J, Fernandez I, GarcíaGutierrez MT, Ruiz-Moreno JM, Rocha-Sousa A, Ramkissoon Y, Harsum S, MacLaren R, Charteris D, Van Meurs J, Gonzalez-Sarmiento R, Pastor JC: The T309G MDM2 gene polymorphism is a novel risk factor for Proliferative Vitreoretinopathy. PloS One 2013;8:e82283.


29

PVR: From Flare to Fibrosis Robert Hoerster, Sascha Fauser, Bernd Kirchhof Center of Ophthalmology, University of Cologne, Kerpener Strasse 62, 50924 Cologne, Germany E-Mail [email protected]

The breakdown of the blood retinal barrier, accompanied by influx of proteins into the vitreous and the anterior chamber is a major risk factor for the development of proliferative vitreoretinopathy (PVR). This breakdown can be quantified by laser flare photometry in the anterior chamber. We have found that elevated laser flare values, representing increased protein levels in the aqueous humour of patients with primary rhegmatogenous retinal detachment are a strong predictor for later PVR development [1]. By fluorescent bead-based immunoassays we identified a distinct pattern of elevated pro-fibrotic cytokines and growth-factors: IL-6, IL-8, MCP-1 and TGF-β1 were elevated in aqueous humour and signified an increased risk for later PVR development. Levels of VEGFA, PDGF-aa and TGF-β2 were not significantly changed [2]. In the pathogenesis of PVR, TGF-β is suspected to induce epithelial to mesenchymal transition (EMT) of RPE-cells [3, 4]. In a rabbit model of PVR we found that elevation of TGF-β1 but not TGF-β2 correlated with the stage of PVR, as well as with the amount of EMT-specific cytosceletal proteins alpha smooth muscle actin and vimentin. In this model TGF-β1 increased early in disease and decreased thereafter, while TGF-β2 increased by a lower rate but stayed elevated over the follow up period [5]. Immunohistochemical analysis of human PVR membranes showed RPE-cell transformation in membranes of early PVR-stage and glial-cell proliferation in membranes of later PVR stage. TGF-β receptor 1 co-localized with RPE-cells and TGF-β receptor 2 co-localized with glial cells. It can thus be hypothesized, that there is a stagespecific cell activation of RPE and glial cells in the pathogenesis of PVR. So far specific inhibition of one growth factor alone has not improved the PVR-rate in animal models. Possibly this is due to bypass-mechanisms via isoforms or other growth factors. Therefore this new information is crucial for further development of specific antibodies targeting growth factors like TGF-β isoforms.

30


References 1 Schröder S, et al: Aqueous flare in the anterior chamber is a predictor for PVR in patients with rhegmatogenous retinal detachment. Retina in press, 2011. 2 Hoerster R, et al: Profibrotic cytokines in aqueous humour correlate with aqueous flare in patients with rhegmatogenous retinal detachment. Br J Ophthalmol 2013;97(4):450–453. 3 Kita T, et al: Role of TGF-beta in proliferative vitreoretinal diseases and ROCK as a therapeutic target. Proc Natl Acad Sci USA 2008;105(45): 17504–17509. 4 Parapuram SK, et al: Differential effects of TGFbeta and vitreous on the transformation of retinal pigment epithelial cells. Invest Ophthalmol Vis Sci 2009;50(12):5965–5974. 5 Hoerster R, et al: Upregulation of TGF-ss1 in experimental proliferative vitreoretinopathy is accompanied by epithelial to mesenchymal transition. Graefes Arch Clin Exp Ophthalmol, 2013.

Retinal Reattachment Without Tamponade: Preliminary Findings from an Animal Model Wilson J. Heriot Franzco Principal Investigator, Vitreo-retinal Surgery, Centre for Eye Research Australia, University of Melbourne, Department of Ophthalmology, Malvern, Australia E-Mail [email protected]

Traditional retinal reattachment, as pioneered by Gonin [1], relies on an inflammatory wound response to bridge the subretinal space and seal retinal tear margins. Tamponade is essential to maintain tissue apposition as the wound matures. Vicente Martinez-Castillo has published his technique for retinal detachment repair without tamponade [2] but others have difficulty reproducing his success. I proposed the hypothesis that instantaneous closure of a retinal tear is possible by fusion of the retinal pigment epithelium (RPE) with the retina if the intervening subretinal fluid (SRF) is removed prior to thermal coagulation. Both the RPE and retina have lipid (hydrophobic) cell membranes separated by SRF from the detachment. The presence of SRF prevents contact so they coagulate independently when heated and thus cannot fuse. Removal of the SRF brings the RPE and retina into contact prior to heating and they will fuse into a united coagulum which provides an instant seal-retinal thermofusion. This process is analogous to cooking eggs where the eggs if heated separately, cannot combine. If they are in contact prior to heating, they will unify. An animal model has been developed to test this hypothesis and to explore optimal conditions for retinal fusion to the RPE. Adult pigmented rabbits underwent lensectomy, pars plana vitrectomy, retinal detachment by Abstracts

subretinal BSS injection, enlargement of the retinal hole and then fluid gas exchange to reattach the retina. The subretinal space adjacent the retina hole was dehydrated with an air stream. Laser was then applied to coagulate and fuse retina with RPE/choroid. Successful fusion was demonstrated histologically. Control eyes without retinal tear margin drying showed persistent fluid in the subretinal space, retinal and RPE/choroidal thermal changes but without fusion. An invitro animal model of post mortem detachment confirms the principle that fusion occurs and is independent of active wound healing, tamponade or time. A novel device has been developed which provides controlled temperature air. A room temperature airstream is used to dry the retina/subretinal space followed by controlled temperature hot air to coagulate the retina and RPE. This device allows assessment of the optimal fusion temperature whereas laser does not. Intraoperative sealing of retinal tear margins offers immediate stable retinal reattachment and is the ideal way to treat all tears with a particular benefit for inferior retinal tears or other situations where maintaining tamponade is difficult – e.g. in children. Retinal thermofusion should reduce the need for long acting tamponade. It also offers an explanation as to why laser barrier treatment of fresh retinal tears is so effective in preventing retinal detachment – immediate fusion occurs around the margin rather than delayed would healing. It also suggests that pneumatic retinopexy could work more reliably if the retinopexy modality is not cryotherapy (which causes inflammation alone) but laser coagulation performed after a 24 hour delay to allow dehydration of the subretinal space. Cryotherapy, although convenient to apply on the same day as the gas injection, relies on delayed wound healing during which the bubble progressively provides less extensive support. Optimisation of the retinal thermofusion technique is being explored in both an in vitro and in vivo models.

References 1 Gonin J: La pathogenie du decollement spontane de la retine. Ann d’Ocullist Paris 132:30 1904. 2 Martínez-Castillo V, Zapata MA, Boixadera A, Fonollosa A, García-Arumí J: Pars plana vitrectomy, laser retinopexy, and aqueous tamponade for pseudophakic rhegmatogenous retinal detachment. Ophthalmology 2007;114(2):297–302.

Abstracts

OCT Changes After RD Surgery: IS/OS Microfolds H. Stevie Tan, Roberto dell’Omo, Marco Mura Dept. of Ophthalmology, AMC, Amsterdam, The Netherlands E-Mail [email protected]

Patients treated for retinal detachment often experience poor visual acuity and metamorphosia in the postoperative period, despite successfull retinal reattachment. Fundus autofluorescence and spectral-domain OCT imaging of the macula show a variety of changes: outer retinal folds, inner retinal folds, skip-lesions in the IS/OS layer and pockets of subretinal fluid. These changes appear to occur very commonly after RD surgery. In the first months after surgery, these lesions tend to resolve spontaneously.

Autofluorescence Changes After Retinal Detachment Surgery, Posture and Tamponade Edward Lee Department of Ophthalmology, St. Thomas’ Hospital, London, UK E-Mail [email protected]

Fundus autofluorescence (FAF) imaging has been used to demonstrate that the macula is commonly misaligned, relative to its pre-detachment position, in patients following retinal detachment repair and that this can be associated with symptoms of distorted vision in the early post-operative course [1–4]. Shiragami and colleagues described in 2010 how autofluorescence (FAF) imaging with Spaide filters can be used to detect hyperautofluorescent lines following rhegmatogenous retinal detachment repair that run parallel to re-attached blood vessels with a similar contour [1]. The hyperautofluorescent lines, also referred to in the literature as ‘RPE vessel ghosts’ or ‘Retinal Vessel Printings’ (RVPs), indicate where the blood vessels used to lie prior to the retinal detachment. We have observed such lines persisting for over a year following retinal detachment repair, and in patients with epiretinal membrane who have a less acute contraction and displacement of the macula [5]. They are believed to reflect an accumulation of lipofuscin in RPE cells that previously resided under retinal blood vessels but following retinal displacement lie under light-stimulated retina; this change is associated with increased demands for pigOphthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

31

ment recycling and phagocytosis of photoreceptor outer segments. We studied a consecutive series of patients undergoing retinal detachment repair and found that in those having vitrectomy, retinopexy and gas procedures for maculainvolving detachments, 72% had autofluorescence evidence of displacement post-operatively [2]. In the series of Shiragami et al., which used a similar imaging system, 63% of macula-involving detachments were affected [1]. In all cases of these series and those of Codenotti et al. [6], dell’Omo et al. [3] and Pandya et al. [4] the hyperautofluorescent lines were seen just above the corresponding retinal blood vessels, indicating a relative downwards displacement of the retina. Patients in our series were also asked if they were aware of distorted vision in the operated eye, or a difference in image size between the two eyes. There was a high level of concordance between FAF evidence of retinal displacement and postoperative symptoms of distortion. In all patients in whom a difference in image size had been noted between the two eyes, the image was perceived as smaller with the post-retinal detachment repair eye (micropsia). Patients sometimes describe this as the image appearing further away. We went on to measure the amplitude of displacement at different positions within the macula, which demonstrated that the displacement was non-uniform. This is key as it shows the retina has not just been rotated around the disc but instead has been variably stretched or compressed, which is in keeping with the symptoms of distortion. The prevalence of micropsia symptoms suggests that the fovea itself is typically stretched such that incident light from a distant object stimulates a smaller number of photoreceptors than in the fellow eye, and so is perceived as smaller. The fact that displacement is invariably downwards in eyes with gas tamponade suggests gravity has a role in the aetiology, and that post-operative posturing may therefore have a role in prevention. Exactly how patients should be postured following surgery to prevent displacement is however unclear. Many of the patients in our series were postured macula-down for at least one hour postoperatively; face-down (to drain any residual fluid away from the macula) or face-up (to prevent a fluid-gas gradient across the macula) can also be used. It is also likely that adequate drainage of subretinal fluid and the prevention of hypotony play a role in prevention, as these factors contribute to the more extreme retinal displacement seen with full thickness macula folds [3, 7]. 32


Until recently our ability to quantify or explain symptoms of distortion following retinal detachment repair has been limited. Advancements in autofluorescence as well as OCT imaging permit investigation of the anatomical basis for these symptoms and consideration of how they may be prevented.

References 1 Shiragami C, et al: Unintentional displacement of the retina after standard vitrectomy for rhegmatogenous retinal detachment. Ophthalmology 2010;117:86–92. 2 Lee E, et al: Macular displacement following rhegmatogenous retinal detachment repair. Br J Ophthalmol 2013;97:1297–1302. 3 Dell’Omo R, Mura M, Lesnik Oberstein SY, Bijl H, Tan HS: Early simultaneous fundus autofluorescence and optical coherence tomography features after pars plana vitrectomy for primary rhegmatogenous retinal detachment. Retina 2012;32:719–728. 4 Pandya VB, Ho I-V, Hunyor AP: Does unintentional macular translocation after retinal detachment repair influence visual outcome? Clin Experiment Ophthalmol 2012;40:88–92. 5 Nitta E, et al: Displacement of the retina and its recovery after vitrectomy in idiopathic epiretinal membrane. Am J Ophthalmol 2013;155:1014– 1020. 6 Codenotti M, et al: Influence of intraocular tamponade on unintentional retinal displacement after vitrectomy for rhegmatogenous retinal detachment. Retina 2013;33:349–355. 7 Heimann H, Bopp S: Retinal folds following retinal detachment surgery. Ophthalmologica 2011;226(Suppl 1):18–26.

Persistent Submacular Fluid After Retinal Detachment Surgery: Aetiology, Natural History and Therapeutic Options Marc Veckeneer Rotterdam Eye Hospital, Schiedamse Vest 180, 3000 LM, Rotterdam, The Netherlands E-Mail [email protected]

In most cases of uncomplicated rhegmatogenous retinal detachment closing all the breaks will re-attach retina. This principle still holds true more than 100 years after it was introduced by Jules Gonin. At least when re-attachment is assessed by ophthalmoscopy. More recently, OCT images have shown us that a thin layer of fluid can persist postoperatively even when the retina appears attached on fundoscopy. Remnants of fluid can be visualized with OCT in most cases in the early post-op period but in some patients fluid can persist up to 2 years and cause delayed visual recovery and disabling metamorphopsia. Younger age and clinical signs of longstanding detachment may increase the risk of slow recovery due to persistent subretinal fluid (PSF) in the macular era. Abstracts

Several therapeutic strategies to promote fluid resolution postoperatively including medical, laser and surgical have been reported. Without clear benefit however and with potential added iatrogenic harm. Considering the physicochemical properties of subretinal fluid in high risk cases of longstanding detachment we have adopted a preventive strategy. During the procedure coined subretinal fluid lavage, the viscosity is reduced by ‘washing’ the subretinal space with BSS. The resulting liquefied fluid is drained as completely as possible without creating additional breaks either by endodrainage trough the original break in case of vitrectomy or by trans-scleral approach for external repair surgery. Physicochemical properties of any fluid remnants will facilitate the physiological re-absorption reducing the incidence of chronic PSF.

ment without any additional procedure in the postoperative period was achieved in 96.5% of cases and final reattachment was achieved in all cases. Mean follow-up was 16.6 months (6 to 45). Conclusions: These results support the role of subretinal fluid drainage during PPV alone for inferior breaks.

Main Session 9: Retinal Vein Occlusions Surgery

Pathophysiology of Retinal Vein Occlusion Constantin J. Pournaras

Reference Persistent subretinal fluid after surgery for rhegmatogenous retinal detachment: hypothesis and review. Veckeneer M, Derycke L, Lindstedt EW, van Meurs J, Cornelissen M, Bracke M, Van Aken E. Graefes Arch Clin Exp Ophthalmol 2012;250:795–802. doi: 10.1007/s00417-011-1870-y

No Tamponade Surgery for the Management of Primary Rhegmatogenous Retinal Detachment Vicente Martínez-Castillo ICOAB, Hospital Vall d´Hebrón, Barcelona, Spain

Purpose: To describe the surgical technique of Pars

plana vitrectomy alone for the managment of primary rhegmatogenous retinal detachment with inferior breaks only. Material and Methods: Prospective study performed by 1 surgeon and 2 fellows on a single center. Overall, 115 eyes of 115 consecutive patients with primary rhegmatogenous retinal detachment with inferior breaks were included in the study. All patients were treated with the same surgical technique. The drainage of subretinal fluid in inferior breaks is described. A sistematic classification of the postoperative volume of gas in the vitreous cavity is performed in all cases. Results: Mean age was 61.6 years (range 24–90). Mean extension of RRD was 2.3 quadrants (range, 1–4). The macula was detached in 80% of cases. A single break was present in 69.5% and 2 or more breaks in 30.5% of cases. Retinal breaks were located anteriorly in 84.3% while 15.7% were at the equator or posterior. Primary reattachAbstracts

Memorial Rothschild Clinical Research Group, La Colline Ophtalmological Center, Avenue de la roseraie 76A, 1205 Geneva E-Mail [email protected]

Central or branch retinal vein occlusion g constitutes the second most common retinal vascular disease leading to visual loss in developed countries, the most frequent cause being diabetic retinopathy. Patients older of sixth decade of life are most usually affected. A large proportion of patients with retinal vein occlusion have a history of cardiovascular disease, hypertension, diabetes mellitus or open-angle glaucoma. Evaluation for potential coagulation disorders may be indicated, particularly in young patients and in patients with bilateral RVO, a history of previous thromboses or a family history of thrombosis [1]. The hemodynamic modifications on the vasculature of the affected areas in acute retinal vein occlusion, include venous vasodilation as well as the reduction of arteriolar blood flow in the affected area. Decreased [2] or retrograde blood flow into the arterioles, as well as blood flowing from the venules into the capillaries [3] were observed in monkey and cat models of BRVO, respectively. In RVO, venous stasis induces changes in the bloodretina barrier [4] and leads to extravasation and the formation of extracellular retinal edema and hemorrhages. Arteriolar vasoconstriction, which settles in the hours following the occlusion, occurs as a result of either changes in retinal metabolism and NO release [5], or a myogenic vasoconstriction secondary to the intravascular pressure increase in the affected vascular bed [6]. Reduction of arOphthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

33

a

c

b

Fig. 1. Immunolocalization of occludin in arteries and veins and veinules (b) and veins after experimental retinal vein occlusiuon in rats. Confocal microscopy of flatmounted retina. The regular reticulate pattern (a and b) outlining the endothelial cells was locally disrupted (c). Local displacement and absence of staining

suggest damage of the blood–retina barrier.

teriolar blood flow leads to tissue hypoxia confirmed by preretinal intravitreal PO2 measurements [7], Na+/K+ATPase pump dysfunction, formation of intracellular retinal edema, and neuronal cell destruction. Retinal tissue hypoxia is also close related to VEGF and inflammatory factors release by the retinal tissue. BRVO leads, within a few hours, to a microangiopathy characterized by the engorgement of the occluded vein and modifications of the blood-retinal barrier. These alterations are associated with the appearance of extracellular edema in the affected area. Redistribution of occludin, indicative of breakdown of the inner BRB, was demonstrated after experimental retinal vein occlusion in rats (fig. 1) [8]. In addition, a progressive oedema of the nerve fibre, ganglion cell and inner plexiform layers, related to a widely diffused cell necrosis, observed in the affected territory within 4–24 hours is followed by a diffuse oedema of the inner nuclear layer and a wave of apoptosis localized at the periphery of the affected territory. Although necrosis is the predominant form of neuronal death in the early phase, massive delayed neuronal cell death caused by apoptosis occurs on a widespread basis as a result of chronic ischaemia after BRVO in the retina [9]. In ischemic monkey retina induced by BRVO [10] and in patients with ischemic retinal disorders, elevated VEGF levels in vitreous [11] closely correlate with uncontrolled angiogenesis. The widely accepted role of VEGF as an angiogenic factor is very complex, as VEGF not only elicits several signaling pathways but also interacts with the prostaglandin-cycloxygenase system that itself influences retinal blood flow, is involved in inflammation. Therefore, the interplay between the three vasoactive systems, VEGF, PGs and inflammatory factors [12], have an im34


portant impact on the progression of retinal microangiopathies related to ischemia. Visual acuity is often decreased due to the development of macular edema, capillary non-perfusion, and vitreous hemorrhage secondary to retinal neovascularization. Retinal neovascularization appears in approximately 25%. The blood-retinal barrier is disrupted in a BRVO or CRVO, leading to macular oedema, mediated by inflammatory agents, including VEGF [13]. Steroids can be used to block the formation of VEGF and reduce vascular leakage from capillary vessels [14]. In humans with CRVO, a resolution of macular oedema following intravitreal injections with triamcinolone or dexamethasone implants was shown. Anti-VEGF drugs also releave the RVO related macular edema resulting to visual fuction recovery. Thus in addition to systemic factors optimal regulation, to laser treatment for neovascular complications, the intravitreal treatments applied following the instoration of RVO offers new insights for the managmenet of RVO, preserving vision as they reverse the veins abnormal permeability resulting, in resolution of the macular edema.

References 1 Yau JW, Lee P, Wong TY, Best J, Jenkins A: Retinal vein occlusion: an approach to diagnosis, systemic risk factors and management. Intern Med J 2008;38:904–910. 2 Rosen DA, Marshall J, Kohner EM, Hamilton AM, Dollery CT: Experimental retinal branch vein occlusion in rhesus monkeys. II. Retinal blood flow studies. Br J Ophthalmol 1979;63:388–392. 3 Ben-nun J: Capillary blood flow in acute branch retinal vein occlusion. Retina 2001;21:509–512.

Abstracts

4 Wallow IH, Danis RP, Bindley C, Neider M: Cystoid macular degeneration in experimental branch retinal vein occlusion. Ophthalmology 1988;95:1371–1379. 5 Donati G, Pournaras CJ, Pizzolato GP, Tsacopoulos M: Decreased nitric oxide production accounts for secondary arteriolar constriction after retinal branch vein occlusion. Invest Ophthalmol Vis Sci 1997;38:1450– 1457. 6 Stangos AN, Petropoulos IK, Pournaras JA, Mendrinos E, Pournaras CJ: The vasodilatory effect of juxta-arteriolar microinjection of endothelinA receptor inhibitor in healthy and acute branch retinal vein occlusion minipig retinas. Invest Ophthalmol Vis Sci 2010;51:2185–2190. 7 Pournaras CJ, Tsacopoulos M, Strommer K, Gilodi N, Leuenberger PM: Experimental retinal branch vein occlusion in miniature pigs induces local tissue hypoxia and vasoproliferative microangiopathy. Ophthalmology 1990;97:1321–1328. 8 Tsilimbaris MK, Tsoka PA, Christodoulakis M, Gilodi N, Pournaras CJ: Changes of Occludin Distribution After Experimental Retina Vein Thrombosis in Rats. ARVO Meeting Abstracts 2010;51:3573. 9 Donati G, Kapetanios AD, Dubois-Dauphin M, Pournaras CJ: Caspaserelated apoptosis in 1chronic ischaemic microangiopathy following experimental vein occlusion in mini-pigs. Acta Ophthalmol Scan 2008, in press. 10 Miller JW, Adamis AP, Shima DT, D’Amore PA, Moulton RS, O’Reilly MS, Folkman J, Dvorak HF, Brown LF, Berse B: Vascular endothelial growth factor/vascular permeability factor is temporally and spatially correlated with ocular angiogenesis in a primate model. Am J Pathol 1994;145:574–584. 11 Aiello LP, Avery RL, Arrigg PG, Keyt BA, Jampel HD, Shah ST, Pasquale LR, Thieme H, Iwamoto MA, Park JE, et al: Vascular endothelial growth factor in ocular fluid of patients with diabetic retinopathy and other retinal disorders. N Engl J Med 1994;331:1480–1487. 12 Noma H, Minamoto A, Funatsu H, Tsukamoto H, Nakano K, Yamashita H, Mishima HK: Intravitreal levels of vascular endothelial growth factor and interleukin-6 are correlated with macular edema in branch retinal vein occlusion. Graefes Arch Clin Exp Ophthalmol 2006;244:309– 315. 13 Miyake K, Miyake T, Kayazawa F: Blood-aqueous barrier in eyes with retinal vein occlusion. Ophthalmology 1992;99:906–910. 14 Edelman JL, Lutz D, Castro MR: Corticosteroids inhibit VEGF-induced vascular leakage in a rabbit model of blood-retinal and blood-aqueous barrier breakdown. Exp Eye Res 2005;80:249–258.

Laser Bypass or Anastomosis for Central Retinal Vein Occlusion Ian L. McAllister Lions Eye Institute, Center for Ophthalmology and Visual Science, University of Western Australia, 2 Verdun St., Nedlands, WA 6009, Australia E-Mail [email protected]

Central retinal vein occlusion (CRVO) remains a common cause of unilateral visual loss despite advances in treatment. Whilst the nature and the site of the occlusion in the central retinal vein remains controversial there is general agreement that the clinical signs and symptoms in this condition are due to an obstruction to retinal venous outflow. In the acute phase the major cause of visual reduction is predominantly macula oedema, the Abstracts

pathogenesis of this which is probably multifactorial with raised venous hydrostatic pressure, upregulation of various cytokines and inflammatory components all potentially playing a role. Of the various cytokines involved VEGF-A is the most predominant and is known to be upregulated in CRVO and also to increase vascular permeability. A number of agents which have the potential to modify this upregulation have been investigated in phase 3 trials of which the VEGF antagonists such as ranibizumab and aflibercept have shown the most promise [1, 2]. These agents have been effective in resolving the macular oedema with a commensurate improvement in visual acuity (VA) but all suffer from recurrence of the oedema once the effect of the agent has worn off requiring repeated injections for a as of yet undetermined time. Initial VA gains do not appear to be sustained with the HORIZON study showing a loss of 4.1–5.2 letters in the second year [3]. The RETAIN study followed CRVO patients treated with ranibizumab for 4 years and found oedema did not resolve in 56% and in this group the final VA improvement was only 4.3 letters compared with 25.2 letters for the group where the oedema resolved [4]. Clearly there is a group of CRVO patients who don’t do as well with long term VEGF blockade as we would hope. Whilst these intravitreal agents are effective in addressing the VEGF induced break-down in the blood ocular barrier which is one component of CRVO induced macular oedema they fail to address the other major cause which is the elevation of the central venous hydrostatic pressure (CVP), which may be up to 24 times normal [5], caused by the blockage to retinal venous outflow. A high CVP (> central retinal artery diastolic) which is maintained for longer than 6 months is significantly associated with reduced final VA (p < 0.0001), a progressive increase in retinal ischaemia (p = 0.001), and anterior segment neovascularisation (p < 0.001) [6]. The only treatment which has the potential to reduce this is a laser induced chorioretinal venous anastomosis (L-CRA) (fig. 1). The Central Vein Bypass Study (CVBS) is the first prospective randomized multi-centre trial to compare LCRA with conventional treatment for CRVO [7, 8]. The L-CRA directly connects a retinal vein where the venous outflow is obstructed with high intravascular pressure to an unobstructed low pressure choroidal vein as a means of permanently bypassing the occlusion in the central retinal vein. The CVBS by comparison to the CRUISE and COPERNICUS trials showed a slower rate of visual acuity improvement in the group with a successful L-CRA with at 8 months there being a 5.6 letter difference between this and the control group and this improving to a 10.5 letter Ophthalmologica 2014;232(suppl 1):1–36 DOI: 10.1159/000367580

35

a

b

Fig. 1. a CRVO immediately post L-CRA attempt showing minimal amount of haemorrhage seen from the punctured veins above and below the disc (black arrows) (VA 6/60). b 12 months following creation of an L-CRA with VA now 6/9. A large functioning anastomosis is seen inferior to the disc with a smaller one superior nasal.

difference at 12 months. After this the visual acuity difference remained stable with no additional treatment with a slight increase to 11.7 letter difference at the study conclusion at 18 months of follow-up. An additional benefit of an L-CRA is that it was the first treatment to show a reduction in the rate of progression of retinal ischaemia in CRVO [7]. Younger age, better baseline visual acuity and the absence of hypertension were all associated with improved success rates as was evidence of rupture of the vein wall at the time of the laser attempt. High baseline CVP, prolonged fluorescein transit time and the presence of any retinal ischaemia were all associated with a higher incidence of neovascular complications [8]. The L-CRA is created with a purpose built high power density laser with power levels 3–4 W, spot size 50 u and duration 0.1 seconds to create a defect in the side wall of the vein and underlying Bruch’s membrane [7]. The success rate in L-CRA creation has improved to 76% and takes 4–6 weeks to develop. Neovascular complications from the L-CRA site can occur but are usually minor and often don’t require treatment. Those that do are very responsive to VEGF inhibitors [9]. Treatment of CRVO may benefit from an approach that recognises of all of the individual components that are contributing to the formation and maintenance of the macular oedema. The elevated hydrostatic pressure can be addressed with the creation of an L-CRA and once this is established VEGF inhibitors may be able to be used more effectively to reduce macular oedema and limit photoreceptor damage. This approach may help reduce the current burden of treatment in CRVO by reducing the frequency and duration of intravitreal therapy.

36


References 1 Campochiaro PA, Brown DM, Awh CC, Lee Y, Gray S, Saroj N, Murahashi WY, Rubio RG: Sustained benefits from ranibizumab for macular edema following central retinal vein occlusion: twelve-month outcomes of a phase 3 study. Ophthalmology 2011;118:2041–2049. 2 Brown DM, Heier JS, Clark WL, Boyer DS, Vitti R, Berliner AJ, Zeitz O, Sandbrink R, Zhu X, Haller JA: Intravitreal aflibercept injection for macular edema secondary to central retinal vein occlusion: 1-year results from the phase 3 COPERNICUS study. Am J Ophthalmol 2013;155:429– 437. 3 Heier JS, Campochiaro PA, Yau L, Li Z, Saroj N, Rubio RG, Lai P: Ranibizumab for macular edema due to retinal vein occlusions: Long-term follow-up in the HORIZON trial. Ophthalmology 2012;119:802–809. 4 Campochiaro PA, Sophie R, Pearlman J, Brown DM, Boyer DS, Heier JS, Marcus DM, Feiner L, Parel A, for the RETAIN study group: Long-term outcomes in patients with retinal vein occlusion treated with ranibizumab: the RETAIN study. Ophthalmology 2014;121:209–219. 5 Jonas JB: Ophthalmodynamometric assessment of the central retinal vein collapse pressure in eyes with retinal stasis or occlusion. Graefe’s Arch Clin Exp Ophthalmol 2003;241:367–370. 6 McAllister IL, Tan MH, Smithies LA, Wong WL: The effect of central retinal venous pressure in patients with central retinal vein occlusion and a high mean area of nonperfusion. Ophthalmology 2014 (accepted May 2014). 7 McAllister IL, Gillies ME, Smithies LA, Rochtchina E, Harper CA, Daniell MD, Constable IJ, Mitchell P: The central retinal vein bypass study: a trial of laser-induced chorioretinal venous anastomosis for central retinal vein occlusion. Ophthalmology 2010;117:954–965. 8 McAllister IL, Gillies ME, Smithies LA, Rochtchina E, Harper CA, Daniell MD, Constable IJ, Mitchell P: Factors promoting success and influencing complications in laser-induced central vein bypass. Ophthalmology 2012;119:2579–2586. 9 Fong CS, Barry C, McAllister IL: Intravitreal Bevacizumab (Avastin) as a treatment of the neovascular complications of laser-induced chorioretinal anastomosis for nonischaemic central retinal vein occlusion. Clinical & Experimental Ophthalmology 2009;37:485–489.

Abstracts

Copyright: S. Karger AG, Basel 2014. Reproduced with the permission of S. Karger AG, Basel. Further reproduction or distribution (electronic or otherwise) is prohibited without permission from the copyright holder.

Abstracts of the 14th Asian Pacific Congress of Nephrology, 14-17 May 2014, Tokyo, Japan.

2014 ACAPS Congress: Abstracts.

International Neuropsychological Society, 14th European Conference. Durham, England, July 8-11, 1992. Abstracts.

Abstracts of the ILTS 20(th) Annual International Congress, June 3-7, 2014, London, United Kingdom.

Abstracts from the Annual Scientific Meeting of the BSGI, 24-25 April 2014, London, England.

Abstracts of the 14th Annual Congress of the French Speaking Society of Transplantation, 2-5 december, 2014, Caen, France.

Abstracts of the XXIV European Congress of Perinatal Medicine, June 4-7, 2014, Florence, Italy.

Abstracts of the Joint Congress of European Neurology, May 28, 2014, Istanbul, Turkey.

Abstracts of the Joint Congress of European Neurology, 31 May-3 June, 2014, Istanbul, Turkey.

Abstracts of the 11th European Congress on Epileptology, 29 June - 3 July, 2014, Stockholm, Sweden.

Abstracts of the 21th European Congress on Obesity (ECO2014), May 28-31, 2014, Sofia, Bulgaria.

Abstracts of the AAGBI WSM London, 15-17 January 2014.

Abstracts for the 1992 annual meeting of the European Society for Dermatological Research. London, England, April 4-7, 1992.

14th World Congress of Endoscopic Surgery and 22nd International Congress of the European Association for Endoscopic Surgery (EAES) Paris, France, 25-28 June 2014 : Oral Presentations.

14th World Congress of Endoscopic Surgery and 22(nd) International Congress of the European Association for Endoscopic Surgery (EAES) Paris, France, 25-28 June 2014 : Poster Presentations.

14th World Congress of Endoscopic Surgery and 22nd International Congress of the European Association for Endoscopic Surgery (EAES), Paris, France, 25-28 June 2014 : Video Presentations.

Abstracts of the 10th Annual Congress of the European Cardiac Arrhythmia Society, March 23-25, 2014, Munich, Germany.

Abstracts of the 22nd Congress of the European Sleep Research Society, 16-20 September, 2014, Tallinn, Estonia.

Abstracts of the 49th Congress of the European Society for Surgical Research, May 21-24, 2014, Budapest, Hungary.

Abstracts of the 12th European Society for Pediatric Dermatology (ESPD) Congress, 12-14 June, 2014, Kiel, Germany.

Abstracts of the RCOG World Congress 2014, 28-30 March 2014, Hyderabad, India.

Abstracts of the WFH 2014 World Congress, May 11-15, 2014, Melbourne, Australia.

Abstracts from the European Academy of Allergy and Clinical Immunology Congress, 7-11 June, 2014, Copenhagen, Denmark.

Abstracts of the IPA World Congress 2014, May 9-11, 2014, Athens, Greece.