Photo Essay
Edited by Cynthia A. Toth with Sumit Sharma and Dilraj S. Grewal
Comet Lesions in Pseudoxanthoma Elasticum: A Spectral Domain Optical Coherence Tomography Analysis
Fig. 1. In an eye with retinal signs of PXE, such as angioid streaks and peau d’orange, color fundus images (A) showed multiple comet lesions with “comet rain” aspect inferiorly to the optic disk head. Comet lesions appeared as small, roundish chorioretinal atrophies observed as solitary, subretinal nodular white bodies with focal hyperpigmentation. Comet lesions showed increased signal on blue reflectance (B) and on fundus autofluorescence imaging (C).
C
A 40-year-old woman with diagnosis of PXE was imaged with a combined confocal laser opthalmoscope and spectral domain optical coherence tomography device (Spectralis; Heidelberg Engineering, Heidelberg, Germany) to accurately colocalize structures on bidimensional imaging and cross-sectional scans.3 A comet rain was seen inferiorly to the optic disk head bilaterally. Comet lesions showed highly increased signal on blue reflectance and fundus autofluorescence imaging (Figure 1); signal was also increased on near-infrared imaging, whereas it was decreased on late-phase indocyanine green angiography (Figure 2). On spectral domain optical coherence tomography scans (Figure 2), comet lesions appeared as irregular hyporeflective spaces with hyperreflective inner border and focal debrislike deposits above the retinal pigment epithelium. When close to each other, multiple comet lesions could coalescence into a single structure. Interestingly, lesions could have full-thickness chorioretinal extension from the retinal pigment epithelium–Bruch membrane up to the retinal nerve fiber layer and down to the choriocapillaris. Inner and outer retinal layers, retinal pigment epithelium, and choriocapillaris were interrupted by comet lesions, creating a transmission effect. Retinal layers around lesions could be spared or present a downslope effect.
omet lesions are a unique entity seen in patients affected by pseudoxanthoma elasticum (PXE).1 They have been suggested to be the only pathognomonic characteristic of PXE and to be of significant diagnostic value in young PXE patients with no other retinal changes.2 Comet lesions are small, roundish chorioretinal atrophies observed as white bodies in the midperiphery of the fundus or closer to the optic disk (Figure 1). They may present with a tail pointing toward the optic disk, leading to the descriptive term of “comet tail lesions.” Sometimes a spray of comets can be observed, creating an aspect of “comet rain.”2 The pathogenesis of these lesions is unclear, and histologic analysis is not available.
From the *Ophthalmological Unit, Department of Clinical Sciences and Community Health, Ca’ Granda Foundation-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy; and †Department of Ophthalmology, Jacobs Retina Center at Shiley Eye Center, University of California San Diego, La Jolla, California. None of the authors have any financial/conflicting interests to disclose. Reprint requests: Giulio Barteselli, MD, Ophthalmological Unit, Ca’ Granda Foundation-Ospedale Maggiore Policlinico, University of Milan, Via Francesco Sforza 35, 20122 Milan, Italy; e-mail: [email protected]
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1052 RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES
2015 VOLUME 35 NUMBER 5
Fig. 2. Comet lesions were hyperreflective on near-infrared imaging (A). Simultaneous spectral domain optical coherence tomography vertical scan through the lesions (B) showed that they appeared as irregular hyporeflective spaces with hyperreflective inner lining and in some cases as focal debrislike deposits above the RPE, better seen on a magnified view (C). When close to each other, multiple comet lesions could coalescence into a single structure as seen on a magnified view (D). Lesions were hypocyanescent on latephase indocyanine green angiography (E). In the areas affected by comet lesions, simultaneous spectral domain optical coherence tomography horizontal scan (F) showed that inner and outer retinal layers were interrupted and RPE was atrophic, creating a transmission effect. Retinal layers around comet lesions were almost normal or could present a downslope effect, better seen on a magnified view (G). Lesions could present a full-thickness chorioretinal extension from the RPE–Bruch membrane up to the retinal nerve fiber layer and down to the choriocapillaris (H). RPE, retinal pigment epithelium.
This is the first detailed spectral domain optical coherence tomography description of comet lesions. Previous investigators have described these lesions as intraretinal cysts4 or spaces of the outer neurosensory
retina.5 In our case, the peculiar multimodal imaging appearance of comet lesions was presumably originating from the sclera because of severe chorioretinal atrophy. The tomographic appearance suggested a primary
PHOTO ESSAY
location of the lesions at the retinal pigment epithelium– Bruch membrane level, with possible full-thickness extension toward the above retina and the below choriocapillaris. Considering that comet lesions are commonly associated to other PXE retinal signs, such as peau d’orange and angioid streaks, we believe that they may represent a sign of disease chronicity. In particular, they may be secondary to PXE-related extensive calcification of the Bruch membrane with subsequent development of full-thickness chorioretinal degeneration. A histologic study is needed to confirm this hypothesis. Key words: comet tail lesions, comet lesions, pseudoxanthoma elasticum, multimodal imaging, fundus autofluorescence, spectral domain optical coherence tomography. GIULIO BARTESELLI, MD*† FRANCESCO VIOLA, MD* References 1. Gass JD. “Comet” lesion: an ocular sign of pseudoxanthoma elasticum. Retina 2003;23:729–730. 2. Gliem M, Zaeytijd JD, Finger RP, et al. An update on the ocular phenotype in patients with pseudoxanthoma elasticum. Front Genet 2013;4:14. 3. Barteselli G, Bartsch DU, Viola F, et al. Accuracy of the Heidelberg Spectralis in the alignment between near-infrared image
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and tomographic scan in a model eye: a multicenter study. Am J Ophthalmol 2013;156:588–592. 4. Finger RP, Charbel Issa P, Ladewig MS, et al. Pseudoxanthoma elasticum: genetics, clinical manifestations and therapeutic approaches. Surv Ophthalmol 2009;54:272–285. 5. Charbel Issa P, Finger RP, Holz FG, Scholl HP. Multimodal imaging including spectral domain OCT and confocal near infrared reflectance for characterization of outer retinal pathology in pseudoxanthoma elasticum. Invest Ophthalmol Vis Sci 2009;50:5913–5918.
RETINAÒ is now accepting manuscripts for consideration for publication in the Photo Essay section. For a manuscript to be considered for publication within this section, the significance of the manuscript should revolve around the photographs. The photographs should convey an important or unique clinical diagnosis, condition, or treatment. The photographs can be a combination of kodachromes, angiograms, histologic sections, or ancillary diagnostic studies (e.g., echograms, radiograms, CT or MRI studies, arteriograms), all of which are imperative in the evaluation, diagnosis, and/or treatment of the condition that is represented. Overall, the Photo Essay manuscript will be limited to 300 words, five photographs, and five references. All figures submitted in color will be published in color at the expense of the authors. Please refer to the Author Instructions for all other general requirements of manuscripts submitted to RETINAÒ.
Edited by Cynthia A. Toth with Sumit Sharma and Dilraj S. Grewal
Comet Lesions in Pseudoxanthoma Elasticum: A Spectral Domain Optical Coherence Tomography Analysis
Fig. 1. In an eye with retinal signs of PXE, such as angioid streaks and peau d’orange, color fundus images (A) showed multiple comet lesions with “comet rain” aspect inferiorly to the optic disk head. Comet lesions appeared as small, roundish chorioretinal atrophies observed as solitary, subretinal nodular white bodies with focal hyperpigmentation. Comet lesions showed increased signal on blue reflectance (B) and on fundus autofluorescence imaging (C).
C
A 40-year-old woman with diagnosis of PXE was imaged with a combined confocal laser opthalmoscope and spectral domain optical coherence tomography device (Spectralis; Heidelberg Engineering, Heidelberg, Germany) to accurately colocalize structures on bidimensional imaging and cross-sectional scans.3 A comet rain was seen inferiorly to the optic disk head bilaterally. Comet lesions showed highly increased signal on blue reflectance and fundus autofluorescence imaging (Figure 1); signal was also increased on near-infrared imaging, whereas it was decreased on late-phase indocyanine green angiography (Figure 2). On spectral domain optical coherence tomography scans (Figure 2), comet lesions appeared as irregular hyporeflective spaces with hyperreflective inner border and focal debrislike deposits above the retinal pigment epithelium. When close to each other, multiple comet lesions could coalescence into a single structure. Interestingly, lesions could have full-thickness chorioretinal extension from the retinal pigment epithelium–Bruch membrane up to the retinal nerve fiber layer and down to the choriocapillaris. Inner and outer retinal layers, retinal pigment epithelium, and choriocapillaris were interrupted by comet lesions, creating a transmission effect. Retinal layers around lesions could be spared or present a downslope effect.
omet lesions are a unique entity seen in patients affected by pseudoxanthoma elasticum (PXE).1 They have been suggested to be the only pathognomonic characteristic of PXE and to be of significant diagnostic value in young PXE patients with no other retinal changes.2 Comet lesions are small, roundish chorioretinal atrophies observed as white bodies in the midperiphery of the fundus or closer to the optic disk (Figure 1). They may present with a tail pointing toward the optic disk, leading to the descriptive term of “comet tail lesions.” Sometimes a spray of comets can be observed, creating an aspect of “comet rain.”2 The pathogenesis of these lesions is unclear, and histologic analysis is not available.
From the *Ophthalmological Unit, Department of Clinical Sciences and Community Health, Ca’ Granda Foundation-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy; and †Department of Ophthalmology, Jacobs Retina Center at Shiley Eye Center, University of California San Diego, La Jolla, California. None of the authors have any financial/conflicting interests to disclose. Reprint requests: Giulio Barteselli, MD, Ophthalmological Unit, Ca’ Granda Foundation-Ospedale Maggiore Policlinico, University of Milan, Via Francesco Sforza 35, 20122 Milan, Italy; e-mail: [email protected]
1051
1052 RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES
2015 VOLUME 35 NUMBER 5
Fig. 2. Comet lesions were hyperreflective on near-infrared imaging (A). Simultaneous spectral domain optical coherence tomography vertical scan through the lesions (B) showed that they appeared as irregular hyporeflective spaces with hyperreflective inner lining and in some cases as focal debrislike deposits above the RPE, better seen on a magnified view (C). When close to each other, multiple comet lesions could coalescence into a single structure as seen on a magnified view (D). Lesions were hypocyanescent on latephase indocyanine green angiography (E). In the areas affected by comet lesions, simultaneous spectral domain optical coherence tomography horizontal scan (F) showed that inner and outer retinal layers were interrupted and RPE was atrophic, creating a transmission effect. Retinal layers around comet lesions were almost normal or could present a downslope effect, better seen on a magnified view (G). Lesions could present a full-thickness chorioretinal extension from the RPE–Bruch membrane up to the retinal nerve fiber layer and down to the choriocapillaris (H). RPE, retinal pigment epithelium.
This is the first detailed spectral domain optical coherence tomography description of comet lesions. Previous investigators have described these lesions as intraretinal cysts4 or spaces of the outer neurosensory
retina.5 In our case, the peculiar multimodal imaging appearance of comet lesions was presumably originating from the sclera because of severe chorioretinal atrophy. The tomographic appearance suggested a primary
PHOTO ESSAY
location of the lesions at the retinal pigment epithelium– Bruch membrane level, with possible full-thickness extension toward the above retina and the below choriocapillaris. Considering that comet lesions are commonly associated to other PXE retinal signs, such as peau d’orange and angioid streaks, we believe that they may represent a sign of disease chronicity. In particular, they may be secondary to PXE-related extensive calcification of the Bruch membrane with subsequent development of full-thickness chorioretinal degeneration. A histologic study is needed to confirm this hypothesis. Key words: comet tail lesions, comet lesions, pseudoxanthoma elasticum, multimodal imaging, fundus autofluorescence, spectral domain optical coherence tomography. GIULIO BARTESELLI, MD*† FRANCESCO VIOLA, MD* References 1. Gass JD. “Comet” lesion: an ocular sign of pseudoxanthoma elasticum. Retina 2003;23:729–730. 2. Gliem M, Zaeytijd JD, Finger RP, et al. An update on the ocular phenotype in patients with pseudoxanthoma elasticum. Front Genet 2013;4:14. 3. Barteselli G, Bartsch DU, Viola F, et al. Accuracy of the Heidelberg Spectralis in the alignment between near-infrared image
1053
and tomographic scan in a model eye: a multicenter study. Am J Ophthalmol 2013;156:588–592. 4. Finger RP, Charbel Issa P, Ladewig MS, et al. Pseudoxanthoma elasticum: genetics, clinical manifestations and therapeutic approaches. Surv Ophthalmol 2009;54:272–285. 5. Charbel Issa P, Finger RP, Holz FG, Scholl HP. Multimodal imaging including spectral domain OCT and confocal near infrared reflectance for characterization of outer retinal pathology in pseudoxanthoma elasticum. Invest Ophthalmol Vis Sci 2009;50:5913–5918.
RETINAÒ is now accepting manuscripts for consideration for publication in the Photo Essay section. For a manuscript to be considered for publication within this section, the significance of the manuscript should revolve around the photographs. The photographs should convey an important or unique clinical diagnosis, condition, or treatment. The photographs can be a combination of kodachromes, angiograms, histologic sections, or ancillary diagnostic studies (e.g., echograms, radiograms, CT or MRI studies, arteriograms), all of which are imperative in the evaluation, diagnosis, and/or treatment of the condition that is represented. Overall, the Photo Essay manuscript will be limited to 300 words, five photographs, and five references. All figures submitted in color will be published in color at the expense of the authors. Please refer to the Author Instructions for all other general requirements of manuscripts submitted to RETINAÒ.
