REVIEW ARTICLE
Prosthetic iris devices Sathish Srinivasan, FRCSEd, FRCOphth, FACS,*,† Darren S.J. Ting, MBChB,* Michael E. Snyder, MD,‡ Somdutt Prasad, MS, FRCS, FRCOphth, FACS,§ Hans-Reinhard Koch, MD¶ ABSTRACT ● RÉSUMÉ Congenital iris defects may usually present either as subtotal aniridia or colobomatous iris defects. Acquired iris defects are secondary to penetrating iris injury, iatrogenic after surgical excision of iris tumours, collateral trauma after anterior segment surgery, or can be postinflammatory in nature. These iris defects can cause severe visual disability in the form of glare, loss of contrast sensitivity, and loss of best corrected visual acuity. The structural loss of iris can be reconstructed with iris suturing, use of prosthetic iris implants, or by a combination of these, depending on the relative amount of residual iris stromal tissue and health of the underlying pigment epithelium. Since the first implant of a black iris diaphragm posterior chamber intraocular lens in 1994, advances in material and design technology over the last decade have led to advances in the prosthetic material, surgical technique, and instrumentation in the field of prosthetic iris implants. In this article, we review the classification of iris defects, types of iris prosthetic devices, implantation techniques, and complications. Les malformations congénitales de l’iris présentent soit une aniridie quasi-complète ou des défauts colobomateux de l’iris. Les défauts acquis de l’iris sont secondaires à une blessure pénétrante de l’iris, iatrogéniques à la suite d’une excision chirurgicale de tumeurs de l’iris ou d’un trauma collatéral suivant une chirurgie du segment antérieur, ou encore ils peuvent être de nature postinflammatoire. Les déficiences de l’iris peuvent causer de graves conséquences visuelles sous formes d’éblouissement, de perte de sensibilité aux contrastes et de perte de meilleure acuité visuelle corrigée. La perte de structure de l’iris peut être corrigée par la suture de l’iris, l’utilisation d’implants ou une combinaison des deux, selon la somme relative de tissus du stroma et l’état de santé de l’épithélium pigmentaire sous-jacent. Depuis la première implantation d’une lentille intraoculaire de chambre postérieure avec diaphragme irien noir en 1994, les progrès du matériel et de la technologie de la dernière décennie ont fait progresser le domaine des implants prothétiques de l’iris. Dans cet article, nous revoyons la classification des défauts de l’iris, des appareils prosthétiques de l’iris, des techniques et complications de l’implantation.
The natural iris, which forms the anterior part of the uveal tract, plays a critical role in controlling the diameter and the size of the pupil, and thus the amount of light reaching the retina. The iris, which originates embryonically from the neuroectoderm, consists of 2 layers, including the anterior fibrovascular layer called the stroma and the posterior pigmented layer, the iris pigment epithelium. An intact iris diaphragm plays an essential role in achieving a maximal quality of vision by reducing aberrations arising from the lens or peripheral cornea, reducing excessive entry of light that can glare, and increasing the depth of focus.1 Iris defects can be broadly classified as congenital and acquired (Fig. 1). Aniridia, irrespective of the cause, can be either partial with few clock hours of iris defects to subtotal where only a remnant of the iris stump remains or, in some cases, the iris may be entirely absent. In other cases, such as ocular albinism or postuveitis and postdrug responses, the stroma may be intact, but the pigment epithelium may be deficient. Irrespective of the
causative factor, iris defects can cause not only cosmetic concerns to the affected individual, but can also compromise visual quality, with severe glare and loss of contrast sensitivity. Various techniques are currently available to restore pupil size and function. This restoration of size and function can be achieved either at the plane of the ocular surface in the form of a cosmetic contact lens, in the corneal plane with corneal tattooing and/or theoretically intracorneal stromal implants, and finally intraocular at the iris plane. Smaller traumatic iris defects can be managed with suturing the residual iris with McCannel, Siepser, or intracameral microtying iris suture techniques. Larger traumatic iris defects are not amenable to surgical closure and are often associated with other ocular comorbidities like corneal, lenticular, and retinal traumatic injury. In 1964, Peter Choyce2 reported the use of the first intraocular anterior chamber prosthetic iris device (PID). Since then several technological advancements have been
From the *Department of Ophthalmology, University Hospital Ayr, Ayr, Scotland, United Kingdom; †Faculty of Medicine, University of Glasgow, Glasgow, United Kingdom; ‡Cincinnati Eye Institute, Cincinnati, Ohio; §Private Practice, Wirral, United Kingdom; and ¶Private Practice, Bonn, Germany.
Can J Ophthalmol 2014;49:6–17 0008-4182/14/$-see front matter & 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2013.10.001
Originally received Aug. 13, 2013. Final revision Oct. 8, 2013. Accepted Oct. 18, 2013 Correspondence to Sathish Srinivasan, FRCSEd, FRCOphth, FACS, Department of Ophthalmology, 3rd Floor, University Hospital Ayr, Dalmellington Road, Ayr, KA6 6DX, United Kingdom; sathish. [email protected]
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Prosthetic iris devices—Srinivasan et al. Iris-lens diaphragm
Fig. 1 — Causes of iris defect.
achieved in the field of artificial iris implants. The purpose of this article is to review the currently available models and surgical techniques, and analyze the surgical outcomes of these devices.
DESIGNS AND MODELS CHARACTERISTICS
WITH
THEIR
Ever since the first implantation of a PID in 1964, various designs and models of PID have become available. The currently available designs and models of PID with their characteristics are summarized in Table 1.3–5 Clinically, PID can be categorized into 3 groups: (i) iris-lens diaphragm, (ii) endocapsular capsular tension ring (CTR)– based PID, and (iii) customized artificial iris.
As early as 1991, Sundmacher et al.6,7 implanted the first posterior chamber PID, which was an iris-lens diaphragm (Morcher GMBH, Stuttgart, Germany), in treating patients with congenital and traumatic aniridia. It consists of central optic with a polymethylmethacrylate (PMMA) diaphragm of 10-mm diameter with curved haptics and with or without fixation loops (Fig. 2). It provides a central opening of variable diameter with or without the inclusion of a centrally functioning optic. The periphery of the diaphragm is composed of a black copolymer to confer the opacity, simulating the normal iris. Many other types of iris-lens diaphragm are currently available (Table 1, Figs. 2 and 3). Some of the more commonly used iris-lens diaphragms include Morcher Type 67F/G and Ophtec 311.8–23 The main advantage of using iris-lens diaphragm is the ability to correct both aniridia and aphakia simultaneously without the need of an additional intraocular lens (IOL). However, this type of PID is large, rigid, and brittle, and it requires a large corneal incision (150–180 degrees) to allow its placement in the anterior segment. Also, maneuvering this type of PID in the anterior segment is relatively more difficult. Endocapsular capsular tension ring–based prosthetic iris device
Endocapsular CTR-based PID is made of a CTR with segmental iris diaphragm. The narrow cross-sectional profile of the CTR-based PID permit implantation via
Fig. 2 — Currently available models of aniridia implants from Morcher GMBH (Stuttgart, Germany).
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Prosthetic iris devices—Srinivasan et al. Table 1—Various designs and models of prosthetic iris devices that are currently available Company Morcher (Stuttgart, Germany)10
Ophtec (Groningen, the Netherlands)11
Models Aniridia implants
Implantation site
Aniridia ring Partial aniridia implants Partial aniridia ring
Iris-lens diaphragm Segmental PID
311 Aniridia Lens II
Iris-lens diaphragm Iris diaphragm
Sulcus/capsule bag Capsule bag
Iris-lens diaphragm
On the iris
Iris diaphragm
Sulcus
Iris Prosthetic System
Dr. Schmidt Intraocularlinsen (HumanOptics)12
Clinical type Iris-lens diaphragm Segmental PID
Artisan Iris Reconstruction IOL ArtificialIris
Sulcus/capsule bag Sulcus/capsule bag Sulcus Capsule bag
Characteristics Overall diameter: 12.5–13.5 mm; optic diameter: 3.0–6.5 mm; incision size: 410 mm; with or without central optics Size: 10.0–12.5 mm; inner diameter: 3.5–6.0 mm; incision size: 42.0–4.5 mm; all are implanted within the bag except Type 96C Overall diameter: 12.5–14.0 mm; optic diameter: 3.5–5.0 mm; incision size: 47.0–8.0 mm; with or without central optics Size: 10.0–11.0 mm; inner diameter: 4.0–6.5 mm; incision size: 41.8–3.5 mm Overall diameter: 13.75 mm; optic/inner diameter: 4.0 mm; with or without central optics; available in brown, green, and blue Overall diameter: 10.5 mm; inner diameter: 3.0–4.0 mm; used together with PC-IOL and CTR; available in black, brown, green, and blue (CE pending) Anterior chamber iris-lens diaphragm; available in black, grown, green, and blue Overall diameter: 12.8 mm; inner diameter: 3.35 mm; foldable diaphragm; incision: 42.5–4.0 mm; with or without polyester mesh for suture and sutureless fixation, respectively
PID, prosthetic iris device; IOL, intraocular lens; PC, posterior chamber; CTR, capsular tension ring; CE, Conformite´ Europe´enne (European community).
the same small corneal incision was created during phacoemulsification and IOL implant. It is available in various forms depending on the extent of the diaphragm (Table 1, Fig. 2). Morcher Type 50 C, D, E, and F PIDs, when implanted as a set of 2 within the capsular bag, combine to create a peripherally opaque diaphragm. The models have interdigitating fins of varying widths, which create different diameters of pseudopupil aperture. Morcher type 96 F/G elements cover just a few adjacent clock hours when implanted singly.22–28 The main benefits of using this category of PIDs is the smaller corneal incision required for insertion of implant and, thus, minimal risk for intraoperative and postoperative complications.26–28 However, this type of PID is susceptible to fracture because of its brittleness, and an intact capsule bag is required for the implantation. Also, accurate alignment of the implant can be technically demanding; however, newer 50 F (Miller variant) generation of endocapsular CTR-based PID with wider segmental fins with narrower gaps between them make alignment more facile.27 Another multipiece endocapsular design from Ophtec BV (Groningen, the Netherlands) has 2 orthogonal segments and a third central locking element, and comes in 3 lights hues of green, brown, and blue (Fig. 3). This PID requires a larger incision than for phacoemulsification, although smaller than required for the full-sized devices.
Placement of the locking element, however, demands significant intraocular dexterity.29 Foldable iris diaphragms. Two foldable iris diaphragms without optics have been reported. Pozdeyeva et al.30 described a foldable elastomer device with outer springlike elements intended to stabilize it within the ciliary sulcus. This device is not yet commercially available.
Customized artificial iris
Customized artificial iris is a type of PID that consists of only the iris diaphragm without the central optic. The ArtificialIris (known in the United States as Customflex PID; HumanOptics, Erlangen, Germany) is the most commonly used type of customized artificial iris.31–34 It is made of biocompatible hydrophobic silicone elastomer and consists of an iris diaphragm without a central optic. It is custom-made (hand coloured) based on the iris colour of the fellow eye. A photograph of the normal fellow (if available) is supplied to the manufacturer to facilitate this process. The custom artificial iris has an overall diameter of 12.8 mm with a central pupillary opening of 3.35 mm (Fig. 4). It is available either without or with a polyester mesh that is incorporated within the substance of the silicone material. The latter subtype confers a better gripping to the sutures, allowing transscleral suture fixation in cases without capsulozonular stability.
Fig. 3 — Designs and models of Ophtec types of prosthetic iris devices.
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Prosthetic iris devices—Srinivasan et al. traumatic aniridia. Since then the indications of implantation of PID have extended to many other conditions. These include partial and complete congenital aniridia,6,7,11,18–20,23–25,27,35 iris coloboma,19,22,25 ocular albinism,16,18,22,28 congenital syndromic disease,23 traumatic aniridia,6,8–10,12–18,20–27,31–35 traumatic 22,26,35 mydriasis, uveitic iris damage,22,24 and iatrogenic iris defect secondary to surgery and laser treatment.10,14,16,22,25–27,30
SELECTION Fig. 4 — Custom-made artificial iris from HumanOptics.
The foldable property of silicone and the lack of central optics allow the artificial iris to be inserted via a small corneal incision (Fig. 5). The simulation of the photographed fellow iris’s appearance can produce a highly satisfactory cosmetic appearance (Fig. 4). Also, it can be combined with any type of IOLs depending on the patient’s need. However, some surgeons perceive this as a disadvantage because a separate IOL is required.
INDICATIONS DEVICE
FOR THE
USE
OF
PROSTHETIC IRIS
Sundmacher et al.6,7 first implanted the posterior chamber PID to treat patients with congenital and
OF
PROSTHETIC IRIS DEVICE
Various designs and models of PIDs are currently available in the market. This allows the operating surgeons to select the most appropriate PID for their patients with iris defect on an individual basis. Fundamentally, the selection of PID is largely dictated by a number of factors, including the phakic status, the presence of an intact capsule bag, and the severity and extent of the iris defect. Phakic status
PID can be used in phakic, pseudophakic, and aphakic eyes. In aphakic patients with or without capsular support, iris-lens diaphragm can be implanted in the sulcus without or with transscleral suture fixation, respectively. In pseudophakic patients, an endocapsular CTR-based PID can be implanted in the capsular bag after the reopening of the capsule bag with viscoelastic material. Alternatively, an IOL exchange can be performed with a secondary iris-lens
Fig. 5 — Implantation of a custom-made artificial iris (HumanOptics) during cataract surgery in an eye with inferior 180-degree iris loss. CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
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Prosthetic iris devices—Srinivasan et al. diaphragm implanted in the sulcus or within the capsule bag. In addition, a secondary sulcus implantation of ArtificialIris (HumanOptics) in pseudophakic eyes has been described in the literature. In contrast, simultaneous cataract surgery and PID implant, either with iris-lens diaphragm or endocapsular PID, can be performed in phakic patients with iris defect. Although PID has been implanted in phakic patients without simultaneous lens extraction,34,36,37 Snyder and Perez38 cautioned the use of PID in such cases because of the possibility of cataract formation or progression. Integrity of the capsule bag
The presence of an intact capsular bag serves as one of the major determining factors in the selection of PID. For instance, in patients with an intact capsular bag, an endocapsular PID can be implanted within the bag. This is the most preferable option because it has the best safety profile. Alternatively, an iris-lens diaphragm can be implanted in the sulcus or within the capsular bag. However, an intact capsule bag is frequently absent in patients with congenital or traumatic aniridia because of several reasons, including aphakia secondary to previous removal of congenital cataract,20,22,32 damage to the lens or capsule sustained from the trauma,12–14,20,22,24 or capsule damage during combined cataract surgery and PID placement. The latter is more common in congenital aniridics because of the much thinner and fragile nature of the congenital aniridic capsule.22–24 Implantation of an iris-lens diaphragm with transscleral suture fixation will be typically indicated in those patients without an intact capsule bag. Severity and extent of the iris defect
Based on the severity and extent of the iris defect, selection of the PID can be categorized into 3 groups: (i) iris defect of less than 3 clock hours, (ii) 3 to 6 clock hours, and (iii) extending more than 6 clock hours. For all the patients without an intact capsule bag, iris defects of various severities, ranging from a small colobomatous defect to total aniridia, can be corrected only with an iris-lens diaphragm PID with transscleral suture fixation. For those with an intact capsule bag and iris defect that extends more than 6 clock hours, an endocapsular CTR-based PID such as Morcher type 50 can be implanted in pair within the bag to manage the defect, whereas an endocapsular CTR-based PID such as Morcher type 96 can be used to address an iris defect of less than 3 clock hours. Depending on the surgeon’s preference, patients with an iris defect extending between 3 and 6 clock hours can be managed by either using a pair of Morcher type 50 or a pair of Morcher type 96. Cosmesis
Some patients may have greater or lesser concerns about the appearance conferred by the iris device. This may vary
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by iris colour, life philosophy, or personal body image. Black PMMA units do not alter the appearance either favourably or unfavourably. The light colours of the Ophtec devices may be a pleasant improvement for some lighter-eyed patients, whereas others may find the colour or smooth, reflective surface distracting. Custom devices seem to have the greatest likelihood of having a similar appearance to the fellow eye. In albinism, the device is covered by stroma, and thus has no cosmetic implication. We feel compelled to emphasize that this review does not address the NewColorIris, an implant that has been marketed for iris colour change in normal eyes. We are aware of no supportive reports in the world literature, although numerous authors have described severe ocular sequelae from their use.39–47
SURGICAL TECHNIQUE Operating on patients with congenital or traumatic aniridia often poses great challenges to the surgeons. In congenital cases, the potential obstacles include limited visibility because of corneal epithelial disease11,20,22 and aberrant anterior capsule fragility.22–24 Problems with traumatic cases are largely influenced by the collateral damages sustained during the ocular injury. These include poor visibility secondary to corneal scarring,12,20,22 poor red reflex caused by vitreous hemorrhage,12 zonular weakness/ dehiscence,22 and capsular rupture.22,24 Quite often, a combination of different surgical procedures is required simultaneously to manage the traumatic injury.6,10,12,15,19,21 Therefore, meticulous preoperative assessment with careful consideration of the risk and benefit of the surgery is essential. Various surgical techniques have been described in the literature in relation to implantation of different types of PID. Broadly, the surgical technique can be categorized into 3 groups, including sulcus implantation with or without transscleral suture fixation and endocapsular implantation. In this article, we present some of the exemplary techniques that have been performed in recent years. Sulcus implantation with transscleral suture fixation
A conjunctival peritomy is created along the superior limbus from 10 to 2 o’clock. A 10.0-mm-wide superior limbal incision is made; then scleral flaps are prepared at 2 and 8 o’clock for covering suture for iris-lens diaphragm IOL fixation. Viscoelastic material is injected into the anterior chamber before implantation of the IOL. Transscleral IOL fixation 1.5 mm posterior to the limbus at the level of the ciliary sulcus is performed by using 9–0 polypropylene double-arm sutures. The superior incision and the scleral flaps are then closed with 10–0 nylon sutures, and residual viscoelastic material is completely removed. Some surgeons prefer suturing variations with different incision or suture locations and may not
Prosthetic iris devices—Srinivasan et al. uniformly use scleral flaps.13,14,17,23 CV-8 Gore-Tex suture (Gore Medical, Flagstaff, AZ, USA), although not approved for ophthalmic use, also provides excellent stability and has no known biodegradation. Sulcus implantation with capsular support
Sulcus implantation with capsular support is similar to the technique for implantation of posterior chamber IOL in the sulcus with capsular support. The types of PID inserted into the eyes determine the size of corneal incision. For instance, a 3.0- to 3.5-mm corneal incision is required for ArtificialIris, whereas a minimum of 10-mm corneal incision is required for Morcher Type 67 or Ophtec 311 implants. In certain circumstances, viscoelastic materials or iris spatula can be used to lift away the iris remnants, ensuring the PID is implanted in the sulcus instead of in front of the iris or at the anterior chamber angle. However, caution needs to be taken in implanting PID in the sulcus without scleral suture fixation in view of potential risk for migration, uveitis-glaucoma-hyphema, and corneal decompensation in cases of total or near-total aniridia. Endocapsular implantation
In phakic patients, routine phacoemulsification is performed and IOL is implanted into the capsular bag.26 After the implantation of IOL, the anterior capsule is stained (if it had not been stained during the phacoemulsification). Capsule staining permits better visualization, because the red reflexes disappear as the opaque device is inserted. Trypan blue is suitable for most cases; however, we find indocyanine green (ICG; Akorn Pharmaceutical, Lake Forrest, IL, USA) more useful when implanting the black PIDs, because it also fluoresces in the red spectrum under the operative microscope.29 Furthermore, in congenital aniridics, ICG does not compromise the already fragile anterior capsule, whereas Trypan blue does reduce capsular elasticity.48,49 Subsequently, a cohesive ophthalmic viscosurgical device (OVD) opens up the potential space between the IOL and the anterior capsule. The initial corneal incision is then enlarged to accommodate the preselected endocapsular PID. With the Morcher type 50, 2 implants are sequentially inserted and dialed into position so that the fins interlock to create a complete ring. With the Morcher type 96, the implant is dialed within the bag until the single fin corresponds with the area of sectoral iris defect. Some surgeons may find it easier to implant the endocapsular PID before IOL implantation. However, in our experience, we find it easier and safer to implant the IOL first followed by the endocapsular PID as the sharp edges of the PID can rupture the capsular bag if inserted before IOL insertion. At the end of the procedure, the OVD is aspirated and corneal stromal hydration is performed to create a self-sealing wound (Figs. 6 and 7).
Fig. 6 — A, Preoperative photograph showing large superior iris defect in the right eye. B, Postoperative photograph after implantation of custom-made artificial iris from HumanOptics showing excellent cosmetic outcome.
OUTCOMES There is a considerable body of literature concerning the clinical outcomes after the implantation of PID to correct the iris defects. The main reported beneficial effects of PID implant include improved visual acuity, reduced glare and photophobia, and improved cosmetic appearance. All relevant case series reporting the clinical outcome of implantation of PID are summarized in Table 2. Visual acuity
Good visual outcome after implantation of the PID has been consistently reported in many case series (Table 2).6,7,10–32,35 The improvement of vision is attributable to various factors, including reduced spherical and chromatic aberration, increased depth of focus, and reduced glare and photophobia. Also, simultaneous cataract surgery is frequently performed during the insertion of PID, which can contribute to the improvement of visual acuity. CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
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Prosthetic iris devices—Srinivasan et al.
Fig. 7 — Implantation of a partial prosthetic iris device into the capsular bag during cataract surgery in an eye with inferior coloboma.
However, it is important to bear in mind that the Snellen visual outcome is largely influenced by the underlying cause of the iris defect and the comorbidities associated with the operated eyes. This is relevant in the context of both congenital and traumatic iris defects. For instance, Aslam et al.20 and Burk et al.22 reported better visual outcomes in the group with traumatic aniridia as compared with those with congenital aniridia after the implantation of PID. The possible explanation is that congenital aniridia is commonly associated with other ocular comorbidities such as corneal epithelial disease, glaucoma, cataract, optic nerve hypoplasia, and foveal dysgenesis. However, patients with traumatic aniridia may have associated traumatic ocular comorbidities that can affect the final visual outcome.19,27 Therefore, careful preoperative assessment with appropriate counseling before the surgery is essential. Glare
Glare remains as one of the major problems associated with iris defects. Great success of reducing glare and photophobia after implantation of PID has been reported in various studies (Table 2). Most studies11,13,15–19,22–28,31,35 reported a great improvement in the reduction of glare after the PID implantation, with a range of 75% to 100% success rate.
appearance. Various studies14,19,35 have reported good patient satisfaction of the cosmetic appearance after the implantation of PID. The recent innovation of ArtificialIris (HumanOptics) further improves the cosmetic appearance of the affected eyes via custom crafting of the device to an index photo of the normal fellow iris.31,32 However, Sikder et al.39 cautioned the use of PID in improving the cosmetic appearance as the sole purpose in view of the potential intraoperative and postoperative complications. In addition, various reports have highlighted the devastating postoperative complications concerning a specific anterior chamber cosmetic PID, namely, the NewColorIris (see later discussion). Summary
PID serves as an effective treatment modality in addressing iris defects anatomically and functionally. However, it is important to note that the quality of the evidence is not robust because the majority of the studies were of retrospective case series with lack of controls. In addition, cost of PID implants may serve as a barrier to some patients and hospitals. Further high-quality studies (i.e., randomized, controlled trials) will help elucidate the benefit and cost-effectiveness of PID implants in patients with iris defects.
COMPLICATIONS Cosmetic appearance
One of the additional beneficial effects alongside the functional benefits is the improvement of the cosmetic
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The safety of implantation of PID has been demonstrated in many studies; however, several complications
Table 2—Synthesis of case series reporting clinical outcomes and complications of implantation of prosthetic iris devices No.oftreated eyes
Author (yr)
Types of iris defect
Treatment
Types of PID
Outcomes
Sundmacher et al.6 (1994)
13
Congenital
PID þ CS ⫾ PK (2)
Morcher (67, 67B-D)
Improved VA (9, 69%)
Sundmacher et al.7 (1994) Osher and Burk24 (1999)
13
PID ⫾ CS (6) ⫾ PK (7)
Morcher (67, 67B)
Improved VA (11, 85%)
PID ⫾ CS (6) ⫾ AV (1)
Morcher (50C, 67F, 96G)
Improved VA (7/7, 100%); reduced glare (6/6, 100%)
Thompson et al.10 (1999)
7
5 congenital, 8 traumatic 4 congenital, 2 traumatic, 1 uveitic 6 traumatic, 1 iatrogenic
PID ⫾ PK (4) ⫾ AV (5)
Morcher 67G
Improved BCVA (5/7, 71%); reduced glare (1/4, 25%)
7
Complications Capsular tear (1, 8%); haptic rupture (1, 8%); suboptimal implantation site (6/26, 23%); mild prolonged AU (13, 100%); new/progression of glaucoma (4, 31%) Mild prolonged AU (13, 100%), new/progression of glaucoma (6, 46%); suboptimal implantation site (5/26, 19%) Capsular tear (2, 29%); prolonged AU (1, 14%); retinal detachment (1, 14%) Glaucoma (2)* with 1 required glaucoma surgery; retinal detachment (1, 14%); endophthalmitis (1, 14%); VH (1, 14%); implant decentration (3, 43%) New/progression of glaucoma (8, 42%); 4 (21%) required glaucoma surgery; CMO (2, 18%); ECL (3, 27%); progression of CED (4, 21%); mild prolonged AU (19, 100%); explantation of implant (2, 11%) Fractured implant (3, 11%); capsular tear (2, 7%); transient hypotony (2, 7%); mild prolonged AU (1, 4%); CMO (1, 4%), retinal detachment (1, 4%), PCO (6, 21%)
Reinhard et al.11 (2000)
19
Congenital
PID þ CS
Morcher (67, 67B/C/D/G)
Improved VA (14/19, 74%); reduced glare (11/14, 79%)
Burk et al.22 (2001)
28
12 congenital, 12 traumatic, 2 iatrogenic, 2 uveitic Traumatic
PID ⫾ CS (20) ⫾ PK (1) ⫾ GS (1)
Morcher (50C, 67F/G, 96G)
Improved VA (22/28, 79%); reduced glare (23/24, 96%)
PID þ PPV
Morcher 67G
Improved BCVA (5, 83%)
Hypotony (2, 33%); VH (1, 17%); Glaucoma (1)*
15
Traumatic
PID
Morcher 67G
Mild implant decentration/tilt (6, 20%); transient hyphema (1, 7%); VH (2, 13%); glaucoma (2)* with 1 required SLT
Beltrame et al.15 (2003)
10
Traumatic
PID ⫾ CS (2) ⫾ PK (3) ⫾ AV (7) ⫾ PPV (4)
Morcher 67F
Improved UCVA (15, 100%); improved BCVA (8, 53%); reduced glare (15, 100%) Improved BCVA (8, 80%); reduced glare (10, 100%)
Price et al.16 (2004)
10
PID ⫾ CS (1) ⫾ PK (1)
Ophtec 311
Menezo et al.23 (2005) Wong et al.18 (2005) Pozdeyeva et al.30 (2005)
9
7 traumatic, 2 iatrogenic, 1 congenital 5 traumatic, 4 congenital 4 congenital, 2 traumatic 17 traumatic, 3 congenital
PID ⫾ CS (6) ⫾ GS (2) PID ⫾ CS (3)
Morcher (67F/G, 50D, 96F), Ophtec Morcher 67, 67F
PID ⫾ CS (12) ⫾ PK (5) ⫾ PPV (4)
Customized iris-lens diaphragm
PID þ CS
Morcher (50C, 67F/G, 96G)
Omulecki and Snyder12 (2002) Dong et al.13 (2003)
6
20
Mavrikakis et al.25 (2005)
10
Srinivasan et al.26 (2007) Moghimi et al.17 (2007)
5
Miller et al.19 (2007) 28
Karatza et al. (2007) Aslam et al.20 (2008)
PID þ CS
Morcher (50C, 96F)
4
4 traumatic, 4 iatrogenic, 2 congenital 3 traumatic, 2 iatrogenic Traumatic
PID
Morcher 67G, Ophtec 311
9
Traumatic
PID þ PK
Ophtec 311
13
Congenital
PID ⫾ CS (12)
40
25 traumatic, 15 congenital
PID þ CS
Morcher 50C/D, Ophtec 311 Morcher 67F
Improved BCVA (5, 100%); reduced glare (5, 100%) Improved VA (4, 100%); reduced glare (4, 100%); improved contrast sensitivity (4, 100%) Improved BCVA (4, 44%); reduced glare (8, 89%); improved cosmesis (9, 100%) Improved BCVA (8/13, 62%); reduced glare (6/8, 75%) BCVA in traumatic cases: mean logMAR 1.34 improved to 0.54;BCVA in congenital cases: mean logMAR 1.17 improved to 1.01
New/progression of glaucoma (5, 56%) with 4 required laser/surgery; trophic corneal ulcer (1, 11%), rotatory corneal graft (1, 11%) Hyphema (1, 17%); choroidal detachment (1, 17%); persistent CED (1, 17%) VH (1, 5%); hyphema (2, 10%); prolonged AU (1, 5%); choroidal detachment (1, 5%); glaucoma (1, 5%); CMO (1, 5%); graft failure (1, 5%) Anterior capsular tear (1, 10%); mild AU (4, 40%); implant migration (2, 20%) None Implant decentration (1, 25%), glaucoma (2)*
Graft problem (2, 22%); VH (1, 11%); hyphema (1, 11%); prolonged AU (3, 33%); glaucoma (1)*; implant decentration (4, 44%) None Zonular dehiscence (1, 3%); glaucoma (12)* with 6 (15%) required glaucoma surgery; implant migration (1, 2.5%); LSCD (4/15, 27%)
13
Prosthetic iris devices—Srinivasan et al.
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Improved UCVA (9/10, 90%); reduced glare (6/6, 100%); improved photophobia (9/9, 100%) Improved VA (9, 100%); reduced glare (9, 100%) Improved BCVA (1, 17%); reduced glare (6, 100%) Improved BCVA (15, 75%); reduced glare (20, 100%); improved cosmesis (20, 100%) Improved BCVA (9/10, 90%); reduced glare (4/5, 80%)
Prolonged AU (4, 40%); glaucoma (4, 40%) with 1 required surgery; transient hyphema (4, 40%); implant decentration (2, 20%); haptic rupture (2, 20%) Prolonged AU (1, 10%); macular edema (1, 10%)
have been reported in the literature concerning eyes in which implantation of PID has been undertaken (Table 2). These complications may be related to the PID itself or the comorbidities associated with congenital and traumatic aniridia. Complications can be divided into intraoperative and postoperative complications. Intraoperative complications
*Data presented included only patients with new-onset glaucoma after operation; CMO, Cystoid macular edema; PCO, Posterior capsule opacification.
PID, prosthetic iris device; CS, cataract surgery; PK, penetrating keratoplasty; VA, visual acuity; AU, anterior uveitis; AV, anterior vitrectomy; BCVA, best corrected visual acuity; VH, vitreous hemorrhage; ECL, endothelial cell loss; CED, corneal epithelial disease; GS, glaucoma surgery; PPV, pars plana vitrectomy; SLT, selective laser trabeculoplasty; UCVA, uncorrected visual acuity; LSCD, limbal stem cell deficiency; BCGVA, best corrected glare visual acuity; IOP, intraocular pressure.
None ArtificialIris PID ⫾ PK (2) ⫾ GS (2) Traumatic 4
PID ⫾ CS (3) ⫾ GS (1) Traumatic 4
Morcher 67F/G, Ophtec 311 ArtificialIris Traumatic
Petousis et al.14 (2011) Mashor et al.21 (2011) Ayliffe et al.31 (2012) Forlini et al.32 (2013)
16
11
PID þ PK
Complications
Glaucoma (2, 13%); hypotony (2, 13%); phthisis (1, 6%); hyphema (1, 6%); implant decentration (1, 6%), silicone oil prolapse (3 of 8, 38%) Glaucoma (2)* with raised IOP requiring removal of IOL (1, 9%); graft failure (2, 18%) None Morcher (50D, 67F/G/L) PID
Improved BCGVA (13, 100%); reduced glare (10, 77%); improved cosmesis (7, 54%) Improved VA (4/11, 36%); improved cosmesis (11, 69%) Improved BCVA (9/11, 82%); reduced glare (4/9, 44%) Improved UCVA (4/4, 100%); reduced glare (3/3, 100%) VA and glare not reported; good anatomical results (4, 100%)
Outcomes Types of PID
Morcher (50D/F, 96F/S)
Treatment
PID ⫾ CS (9)
7 traumatic, 5 iatrogenic, 1 congenital Traumatic 13 Olson et al.27 (2008)
Types of iris defect No.oftreated eyes Author (yr)
Table 2 (continued )
14
Transient hyphema (1, 8%); implant malpositioning (2, 15%)
Prosthetic iris devices—Srinivasan et al.
CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
The most common intraoperative complications include implant-related problems, capsular tear, and hyphema. Implant-related problems. Although uncommon, broken implants have been reported in a few studies during the loading and implantation phases of the surgery.7,15,22,26 This is due to the brittleness of the implant caused by irradiation treatment of the PMMA material, which confers its black opaque appearance. Therefore, availability of a spare implant and meticulous surgical technique are important to avoid this problem. In addition, implantation of the PID at a suboptimal site may occur intraoperatively. For instance, Sundmacher et al.7 and Reinhard et al.11 reported that 6 (23%) of the 26 PID loops and 8 (21%) of the 38 loops were found to be implanted at the anterior chamber angle, on the rudimentary iris or pars plana instead of the sulcus, respectively. However, suboptimal implantation site can be overcome by implanting an endocapsular PID within the bag.22,26,27 Also, separating the rudimentary iris from the anterior capsule with the aid of OVD or iris spatula can help address this problem.31 Capsular tear. Capsular tear is uncommon during the implantation of PID, with a reported rate of 0% to 10% in most studies.7,20,22,25–27,35 The capsular tear can be related either to the implantation7,24,25 or to the aberrant fragility of the capsule in congenital aniridia.22–24 In spite of the tear, implantation of the PID within the bag or in the sulcus has been safely achieved in most cases without any additional surgical procedure.22,24,25 Hyphema. Intraoperative bleeding or hyphema can occur during the fixation of transscleral suture over ciliary sulcus,15 the posterior synechiolysis,19,27 and the implantation of PID causing traumatic injury to the iris.18 However, the intraoperative bleeding is usually transient and self-limiting. Postoperative complications
The most common complications after implantation of PID include raised intraocular pressure (IOP)/glaucoma, prolonged postoperative inflammation or anterior uveitis, secondary glaucoma, and malpositioning of the implant. intraocular pressure/glaucoma. Raised IOP or glaucoma serves as one of the most commonly reported postoperative complications after implantation of PID.6,7,10–15,17,19,21–23,25 It can present as a new-onset glaucoma or progression of previously controlled glaucoma. This is important because coexisting glaucoma is frequently observed in patients with congenital and
Raised
Prosthetic iris devices—Srinivasan et al. traumatic aniridia.6,7,11,15,21–23 Mashor et al.21 and Burk et al.22 reported that 64% and 39% of their cohort suffered from pre-existing glaucoma before the surgery. Several mechanisms have been proposed in relation to the development of glaucoma after implantation of PID. Reinhard et al.11 reported that 4 (21%) of 19 eyes developed secondary glaucoma after sulcus implantation of the iris-lens diaphragm (various Morcher 67 models). In addition, deterioration of pre-existing glaucoma was noted in 4 (80%) of 5 patients postoperatively. Two (11%) of the cases required trabeculectomy, cyclodestruction, and explantation of the PID to achieve adequate IOP control. They postulated that implantation of the PID can result in chronic alteration of the blood–aqueous barrier (BAB), accelerating the progression of glaucoma.11 This can be due to continuous irritation of the uveal remnants by the diaphragm and haptics, dislocation of the haptics into the anterior chamber angle, and inherent vulnerability of the BAB to all types of trauma in congenital aniridic eyes.11 In contrast, Aslam et al.20 reported an increased prevalence rate of glaucoma from 25% to 40% after sulcus implantation of the iris-lens diaphragm (Morcher 67F). More interestingly, they found that the mean IOP rise occurred within 2 to 3 weeks after the surgery and required IOP-lowering medical or surgical treatment within a year. This suggested that the raised IOP is most likely secondary to the direct mechanical effect of the large iris-lens diaphragm with rigid haptic, either by obstructing the aqueous flow or by compressing the trabecular meshwork. Based on the proposed mechanisms, it is reasonable to hypothesize that the risk for development of glaucoma can be reduced or eliminated by implanting the PID within the bag because it avoids any mechanical pressure or irritation to the uveal tissues and trabecular meshwork. The minimal risk for postoperative glaucoma after implantation of endocapsular PID has been demonstrated in several studies.25–28 Prolonged postoperative inflammation after implantation of PID has been reported in a few studies.6,7,11,24,25 Sundmacher et al.6,7 and Reinhard et al.11 reported that all of their patients experienced a mild persistent intraocular inflammation or anterior uveitis after the implantation of PID. Sundmacher et al.6 suggested that the postoperative prolonged intraocular inflammation might be secondary to the suboptimal positioning of the PID. However, following the improvement of instrumentation and surgical techniques, prolonged postoperative intraocular inflammation has become a lesser problem.13,16,22,24,26,35 Prolonged inflammation/anterior uveitis.
Instability of the PID after the implantation has been reported in some studies.10,13– 15,17,19,20,25,27 However, the extent of decentration, migration, or tilting of the PID was mild in most cases, and further surgical intervention to reposition or realign the PID was rarely required.15 Malpositioning of the implant
Malpositioning of the implant.
is usually observed in patients who received iris-lens diaphragm PID that required transscleral suture fixation. This is because there is lack of mechanical support to the PID (e.g., no capsular support, vitrectomized eye), and some of the iris-lens diaphragms have only 2 fixation points for transscleral suturing. Having a 3-point fixations implant can potentially ameliorate the problem. Although uncommon, Mavrikakis et al.25 reported migration of endocapsular PID in 2 (20%) of the 10 patients caused by anterior capsular tear and capsular contraction in each eye. Other postoperative complications have been noted after implantation of the PID. These include progression or development of corneal epithelial disease in congenital aniridic eyes.11,18 This is fully expected in view of the genetically defined progression of stem cell failure in this cohort with or without intervention. Vitreous hemorrhage,10,12,13,35 retinal detachment,10,22,24 choroidal detachment,18,35 hypotony,12,14,22 endophthalmitis,10 and cystoid macular edema11,22,35 are other reported complications, although they may have similar incidence in eyes that have similar surgeries without a PID.
Other postoperative complications.
COSMETIC IRIS DEVICES: MISUSE COMPLICATIONS
AND
In recent years there has been an increasing concern regarding the long-term safety of specific cosmetic iris devices, namely, NewColorIris (Kahn Medical Devices, Panama City, Panama).39 Hyphema, raised IOP, reduced vision, and corneal edema were the common complications reported.39–47 It has been proposed that these complications are attributed to the direct contact between the implant and the angle structures,41,42,45 and the surface and edge irregularities of the implants causing abrasion to the iris and corneal endothelium.40,42 It is important to distinguish between this discredited device and the reputable devices described earlier.
CONCLUSIONS PID serves as an effective and safe treatment modality in managing patients with iris defect of different underlying pathologies. Promising outcomes, including improved vision, reduced glare, and improved cosmetic appearance, have been reported in many studies. However, meticulous preoperative assessment with judicious selection of appropriate candidates is essential to achieve the best outcome after implantation of PID. Specific guidelines on the selection criteria for patients receiving PID implantation will be useful for the surgeons in the future. We recommend the use of endocapsular PID implant, when it is possible, over the anterior chamber or sulcus PID implants in view of the lesser risk for complications. CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
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Prosthetic iris devices—Srinivasan et al. Future studies with longer-term follow-up period are required to elucidate the long-term effect of PID implants.
Disclosure: The authors have no proprietary or commercial interest in any materials discussed in this article. Dr. Michael Synder is an consultant for Human Optics. Literature Search: Electronic databases including MEDLINE and EMBASE were searched, reference lists were hand-searched, and experts in the field were contacted to identify peer-reviewed literature concerning PID. Only articles written in English were included in this review. Certain keywords were used during the literature search, including PID, artificial iris, and iris reconstruction.
REFERENCES 1. Slomovits TL, Glaser JS. The pupils and accommodation. In: Tasman W, Jaeger E, eds. Duane’s Clinical Ophthalmology, Vol. 2 Philadelphia, Pa: Lippincott Williams & Wilkins; 1998. 2. Choyce P. Intraocular Lenses and Implants. London: HK: Lewis; 1964:27–32,162-78. 3. MORCHER Implants. http://www.morcher.com/nc/en/produkte/ aniridia-implants.html. Accessed May 31, 2013. 4. Ophtec. Trauma surgery product line. http://www.ophtec.com/ professional/en/trauma-surgery/product-line. Accessed May 31, 2013. 5. ArtificialIris. http://www.artificial-iris.com/artificialiris-en.html. Accessed May 31, 2013. 6. Sundmacher R, Reinhard T, Althaus C. Black-diaphragm intraocular lens for correction of aniridia. Ophthalmic Surg. 1994;25:180-5. 7. Sundmacher R, Reinhard T, Althaus C. Black diaphragm intraocular lens in congenital aniridia. Ger J Ophthalmol. 1994;3(4-5):197-201. 8. Tanzer DJ, Smith RE. Black iris–diaphragm intraocular lens for aniridia and aphakia. J Cataract Refract Surg. 1999;25:1548-51. 9. Mavrikakis I, Casey JMH. Phacoemulsification and endocapsular implantation of an artificial iris intraocular lens in traumatic cataract and aniridia. J Cataract Refract Surg. 2002;28:1088-90. 10. Thompson CG, Fawzy K, Bryce IG, Noble BA. Implantation of a black diaphragm intraocular lens for traumatic aniridia. J Cataract Refract Surg. 1999;25:808-13. 11. Reinhard T, Engelhardt S, Sundmacher R. Black diaphragm aniridia intraocular lens for congenital aniridia: long-term follow-up. J Cataract Refract Surg. 2000;26:375-81. 12. Omulecki W, Snyder A. Pars plana vitrectomy and transscleral fixation of black diaphragm intraocular lens for the management of traumatic aniridia. Ophthalmic Surg Lasers. 2002;33:357-61. 13. Dong X, Yu B, Xie L. Black diaphragm intraocular lens implantation in aphakic eyes with traumatic aniridia and previous pars plana vitrectomy. J Cataract Refract Surg. 2003;29:2168-73. 14. Petousis V, Krause L, Willerding G, Foerster MH, Bechrakis NE. Results and complications after implantation of a black iris-lens diaphragm in patients with traumatically induced aphakia and aniridia. Eur J Ophthalmol. 2011;21:754-9. 15. Beltrame G, Salvetat ML, Chizzolini M, et al. Implantation of a black diaphragm intraocular lens in ten cases of post-traumatic aniridia. Eur J Ophthalmol. 2003;13:62-8. 16. Price MO, Price FW Jr, Chang DF, et al. Ophtec iris reconstruction lens United States clinical trial phase I. Ophthalmology. 2004; 111:1847-52. 17. Moghimi S, Riazi Esfahani M, Maghsoudipour M. Visual function after implantation of aniridia intraocular lens for traumatic aniridia in vitrectomized eye. Eur J Ophthalmol. 2007;17:660-5. 18. Wong VW, Lam PT, Lai TY, Lam DS. Black diaphragm aniridia intraocular lens for aniridia and albinism. Graefes Arch Clin Exp Ophthalmol. 2005;243:501-4.
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19. Miller AR, Olson MD, Miller KM. Functional and cosmetic outcomes of combined penetrating keratoplasty and iris reconstruction lens implantation in eyes with a history of trauma. J Cataract Refract Surg. 2007;33:808-14. 20. Aslam SA, Wong SC, Ficker LA, MacLaren RE. Implantation of the black diaphragm intraocular lens in congenital and traumatic aniridia. Ophthalmology. 2008;115:1705-12. 21. Mashor RS, Bahar I, Kaiserman I, et al. Combined penetrating keratoplasy and implantation of iris prosthetic intraocular lenses after ocular trauma. J Cataract Refract Surg. 2011;37:582-7. 22. Burk SE, Da Mata AP, Snyder ME, et al. Prosthetic iris implantation for congenital, traumatic, or functional iris deficiencies. J Cataract Refract Surg. 2001;27:1732-40. 23. Menezo JL, Martinez-Costa R, Cisneros A, Desco MC. Implantation of iris devices in congenital and traumatic aniridias: surgery solutions and complications. Eur J Ophthalmol. 2005;15: 451-457. 24. Osher RH, Burk SE. Cataract surgery combined with implantation of an artificial iris. J Cataract Refract Surg. 1999;25:1540-7. 25. Mavrikakis I, Mavrikakis E, Syam PP, et al. Surgical management of iris defects with prosthetic iris devices. Eye. 2005;19:205-9. 26. Srinivasan S, Yuen C, Watts M, Prasad S. Endocapsular iris reconstruction implants for acquired iris defects: a clinical study. Eye. 2007;21:1109-13. 27. Olson MD, Masket S, Miller KM. Interim results of a compassionate-use clinical trial of Morcher iris diaphragm implantation: report 1. J Cataract Refract Surg. 2008;34:1674-80. 28. Karatza EC, Burk SE, Snyder ME, Osher RH. Outcomes of prosthetic iris implantation in patients with albinism. J Cataract Refract Surg. 2007;33:1763-9. 29. Khng C, Snyder ME. Iris reconstruction with a multipiece endocapsular prosthesis in iridocorneal endothelial syndrome. J Cataract Refract Surg. 2005;31:2051-4. 30. Pozdeyeva NA, Pashtayev NP, Lukin VP, Batkov YN. Artificial irislens diaphragm in reconstructive surgery for aniridia and aphakia. J Cataract Refract Surg. 2005;31:1750-9. 31. Ayliffe W, Groth SL, Sponsel WE. Small incision insertion of artificial iris prostheses. J Cataract Refract Surg. 2012;38:362-7. 32. Forlini C, Forlini M, Rejdak R, et al. Simultaneous correction of post-traumatic aphakia and aniridia with the use of artificial iris and IOL implantation. Graefes Arch Clin Exp Ophthalmol. 2013; 251:667-75. 33. Rana M, Savant V, Prydal JI. A new customized artificial iris diaphragm for treatment of traumatic aniridia. Cont Lens Anterior Eye. 2013;36:93-4. 34. Magnus J, Trau R, Mathysen DGP, Tassignon M-J. Safety of an artificial iris in a phakic eye. J Cataract Refract Surg. 2012;38: 1097-1100. 35. Beltran-Agullo L, Alaghband P, Gurbaxani A, Lim KS. Phacoemulsification with therapeutic implantation of a prosthetic iris device following peripheral iridotomy visual complication. Eye. 2011; 25:1096. 36. Sakellaris D, Goossens C, Tassignon MJ. Customized iris clip anterior chamber intraocular lenses designed for iris reconstruction. Eur J Ophthalmol. 2009;19:1084-7. 37. de Keizer RJ, Razzaq L, Tassignon MJ, Verbeek AM. Iris melanoma in a child treated with iridectomy and a phakic iris repair implant lens: a case report of 8 years postoperative follow-up. Br J Ophthalmol. 2010;94:953-4. 38. Snyder ME, Perez MA. Phakic implantation of flexible iris prosthesis. J Cataract Refract Surg. 2012;38:2208-9. 39. Sikder S, Davis SW, Holz H, Moshirfar M. Complications of NewColorIris implantation in phakic eyes: a review. Clin Ophthalmol. 2011;5:435-8. 40. Anderson JE, Grippo TM, Sbeity Z, Ritch R. Serious complications of cosmetic NewColorIris implantation. Acta Ophthalmol. 2010;88:700-4. 41. Arthur SN, Wright MM, Kramarevsky N, Kaufman SC, Grajewski AL. Uveitis-glaucoma-hyphema syndrome and corneal decompensation in association with cosmetic iris implants. Am J Ophthalmol. 2009;148:790-3. 42. Castanera F, Fuentes-Páez G, Ten P, Pinalla B, Guevara O. Scanning electron microscopy of explanted cosmetic iris implants. Clin Experiment Ophthalmol. 2010;38:648-51.
Prosthetic iris devices—Srinivasan et al. 43. Hull S, Jayaram H, Mearza AA. Complications and management of cosmetic anterior chamber iris implants. Cont Lens Anterior Eye. 2010;33:235-8. 44. MacDonald L. Cosmetic iris implants—is vanity worth losing your vision? Optometry J Am Optometric Assoc. 2010;81:281-2. 45. Thiagalingam S, Tarongoy P, Hamrah P, et al. Complications of cosmetic iris implants. J Cataract Refract Surg. 2008;34:1222-4. 46. Sikder S, Davis SW, Patel VP, Holz H, Moshirfar M. Complications and management of NewColorIris implantation in phakic eyes. J Refract Surg. 2011;27:239-40.
47. George MK, Tsai JC, Loewen NA. Bilateral irreversible severe vision loss from cosmetic iris implants. Am J Ophthalmol. 2011;151: 872-875. 48. Dick HB, Aliyeva SE, Hengerer F. Effect of trypan blue on the elasticity of the human anterior lens capsule. J Cataract Refract Surg. 2008;34:1367-73. 49. Jardeleza MS, Daly MK, Kaufman JD, Klapperich C, Legutko PA. Effect of trypan blue staining on the elastic modulus of anterior lens capsules of diabetic and nondiabetic patients. J Cataract Refract Surg. 2009;35:318-23.
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Prosthetic iris devices Sathish Srinivasan, FRCSEd, FRCOphth, FACS,*,† Darren S.J. Ting, MBChB,* Michael E. Snyder, MD,‡ Somdutt Prasad, MS, FRCS, FRCOphth, FACS,§ Hans-Reinhard Koch, MD¶ ABSTRACT ● RÉSUMÉ Congenital iris defects may usually present either as subtotal aniridia or colobomatous iris defects. Acquired iris defects are secondary to penetrating iris injury, iatrogenic after surgical excision of iris tumours, collateral trauma after anterior segment surgery, or can be postinflammatory in nature. These iris defects can cause severe visual disability in the form of glare, loss of contrast sensitivity, and loss of best corrected visual acuity. The structural loss of iris can be reconstructed with iris suturing, use of prosthetic iris implants, or by a combination of these, depending on the relative amount of residual iris stromal tissue and health of the underlying pigment epithelium. Since the first implant of a black iris diaphragm posterior chamber intraocular lens in 1994, advances in material and design technology over the last decade have led to advances in the prosthetic material, surgical technique, and instrumentation in the field of prosthetic iris implants. In this article, we review the classification of iris defects, types of iris prosthetic devices, implantation techniques, and complications. Les malformations congénitales de l’iris présentent soit une aniridie quasi-complète ou des défauts colobomateux de l’iris. Les défauts acquis de l’iris sont secondaires à une blessure pénétrante de l’iris, iatrogéniques à la suite d’une excision chirurgicale de tumeurs de l’iris ou d’un trauma collatéral suivant une chirurgie du segment antérieur, ou encore ils peuvent être de nature postinflammatoire. Les déficiences de l’iris peuvent causer de graves conséquences visuelles sous formes d’éblouissement, de perte de sensibilité aux contrastes et de perte de meilleure acuité visuelle corrigée. La perte de structure de l’iris peut être corrigée par la suture de l’iris, l’utilisation d’implants ou une combinaison des deux, selon la somme relative de tissus du stroma et l’état de santé de l’épithélium pigmentaire sous-jacent. Depuis la première implantation d’une lentille intraoculaire de chambre postérieure avec diaphragme irien noir en 1994, les progrès du matériel et de la technologie de la dernière décennie ont fait progresser le domaine des implants prothétiques de l’iris. Dans cet article, nous revoyons la classification des défauts de l’iris, des appareils prosthétiques de l’iris, des techniques et complications de l’implantation.
The natural iris, which forms the anterior part of the uveal tract, plays a critical role in controlling the diameter and the size of the pupil, and thus the amount of light reaching the retina. The iris, which originates embryonically from the neuroectoderm, consists of 2 layers, including the anterior fibrovascular layer called the stroma and the posterior pigmented layer, the iris pigment epithelium. An intact iris diaphragm plays an essential role in achieving a maximal quality of vision by reducing aberrations arising from the lens or peripheral cornea, reducing excessive entry of light that can glare, and increasing the depth of focus.1 Iris defects can be broadly classified as congenital and acquired (Fig. 1). Aniridia, irrespective of the cause, can be either partial with few clock hours of iris defects to subtotal where only a remnant of the iris stump remains or, in some cases, the iris may be entirely absent. In other cases, such as ocular albinism or postuveitis and postdrug responses, the stroma may be intact, but the pigment epithelium may be deficient. Irrespective of the
causative factor, iris defects can cause not only cosmetic concerns to the affected individual, but can also compromise visual quality, with severe glare and loss of contrast sensitivity. Various techniques are currently available to restore pupil size and function. This restoration of size and function can be achieved either at the plane of the ocular surface in the form of a cosmetic contact lens, in the corneal plane with corneal tattooing and/or theoretically intracorneal stromal implants, and finally intraocular at the iris plane. Smaller traumatic iris defects can be managed with suturing the residual iris with McCannel, Siepser, or intracameral microtying iris suture techniques. Larger traumatic iris defects are not amenable to surgical closure and are often associated with other ocular comorbidities like corneal, lenticular, and retinal traumatic injury. In 1964, Peter Choyce2 reported the use of the first intraocular anterior chamber prosthetic iris device (PID). Since then several technological advancements have been
From the *Department of Ophthalmology, University Hospital Ayr, Ayr, Scotland, United Kingdom; †Faculty of Medicine, University of Glasgow, Glasgow, United Kingdom; ‡Cincinnati Eye Institute, Cincinnati, Ohio; §Private Practice, Wirral, United Kingdom; and ¶Private Practice, Bonn, Germany.
Can J Ophthalmol 2014;49:6–17 0008-4182/14/$-see front matter & 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2013.10.001
Originally received Aug. 13, 2013. Final revision Oct. 8, 2013. Accepted Oct. 18, 2013 Correspondence to Sathish Srinivasan, FRCSEd, FRCOphth, FACS, Department of Ophthalmology, 3rd Floor, University Hospital Ayr, Dalmellington Road, Ayr, KA6 6DX, United Kingdom; sathish. [email protected]
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Prosthetic iris devices—Srinivasan et al. Iris-lens diaphragm
Fig. 1 — Causes of iris defect.
achieved in the field of artificial iris implants. The purpose of this article is to review the currently available models and surgical techniques, and analyze the surgical outcomes of these devices.
DESIGNS AND MODELS CHARACTERISTICS
WITH
THEIR
Ever since the first implantation of a PID in 1964, various designs and models of PID have become available. The currently available designs and models of PID with their characteristics are summarized in Table 1.3–5 Clinically, PID can be categorized into 3 groups: (i) iris-lens diaphragm, (ii) endocapsular capsular tension ring (CTR)– based PID, and (iii) customized artificial iris.
As early as 1991, Sundmacher et al.6,7 implanted the first posterior chamber PID, which was an iris-lens diaphragm (Morcher GMBH, Stuttgart, Germany), in treating patients with congenital and traumatic aniridia. It consists of central optic with a polymethylmethacrylate (PMMA) diaphragm of 10-mm diameter with curved haptics and with or without fixation loops (Fig. 2). It provides a central opening of variable diameter with or without the inclusion of a centrally functioning optic. The periphery of the diaphragm is composed of a black copolymer to confer the opacity, simulating the normal iris. Many other types of iris-lens diaphragm are currently available (Table 1, Figs. 2 and 3). Some of the more commonly used iris-lens diaphragms include Morcher Type 67F/G and Ophtec 311.8–23 The main advantage of using iris-lens diaphragm is the ability to correct both aniridia and aphakia simultaneously without the need of an additional intraocular lens (IOL). However, this type of PID is large, rigid, and brittle, and it requires a large corneal incision (150–180 degrees) to allow its placement in the anterior segment. Also, maneuvering this type of PID in the anterior segment is relatively more difficult. Endocapsular capsular tension ring–based prosthetic iris device
Endocapsular CTR-based PID is made of a CTR with segmental iris diaphragm. The narrow cross-sectional profile of the CTR-based PID permit implantation via
Fig. 2 — Currently available models of aniridia implants from Morcher GMBH (Stuttgart, Germany).
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Prosthetic iris devices—Srinivasan et al. Table 1—Various designs and models of prosthetic iris devices that are currently available Company Morcher (Stuttgart, Germany)10
Ophtec (Groningen, the Netherlands)11
Models Aniridia implants
Implantation site
Aniridia ring Partial aniridia implants Partial aniridia ring
Iris-lens diaphragm Segmental PID
311 Aniridia Lens II
Iris-lens diaphragm Iris diaphragm
Sulcus/capsule bag Capsule bag
Iris-lens diaphragm
On the iris
Iris diaphragm
Sulcus
Iris Prosthetic System
Dr. Schmidt Intraocularlinsen (HumanOptics)12
Clinical type Iris-lens diaphragm Segmental PID
Artisan Iris Reconstruction IOL ArtificialIris
Sulcus/capsule bag Sulcus/capsule bag Sulcus Capsule bag
Characteristics Overall diameter: 12.5–13.5 mm; optic diameter: 3.0–6.5 mm; incision size: 410 mm; with or without central optics Size: 10.0–12.5 mm; inner diameter: 3.5–6.0 mm; incision size: 42.0–4.5 mm; all are implanted within the bag except Type 96C Overall diameter: 12.5–14.0 mm; optic diameter: 3.5–5.0 mm; incision size: 47.0–8.0 mm; with or without central optics Size: 10.0–11.0 mm; inner diameter: 4.0–6.5 mm; incision size: 41.8–3.5 mm Overall diameter: 13.75 mm; optic/inner diameter: 4.0 mm; with or without central optics; available in brown, green, and blue Overall diameter: 10.5 mm; inner diameter: 3.0–4.0 mm; used together with PC-IOL and CTR; available in black, brown, green, and blue (CE pending) Anterior chamber iris-lens diaphragm; available in black, grown, green, and blue Overall diameter: 12.8 mm; inner diameter: 3.35 mm; foldable diaphragm; incision: 42.5–4.0 mm; with or without polyester mesh for suture and sutureless fixation, respectively
PID, prosthetic iris device; IOL, intraocular lens; PC, posterior chamber; CTR, capsular tension ring; CE, Conformite´ Europe´enne (European community).
the same small corneal incision was created during phacoemulsification and IOL implant. It is available in various forms depending on the extent of the diaphragm (Table 1, Fig. 2). Morcher Type 50 C, D, E, and F PIDs, when implanted as a set of 2 within the capsular bag, combine to create a peripherally opaque diaphragm. The models have interdigitating fins of varying widths, which create different diameters of pseudopupil aperture. Morcher type 96 F/G elements cover just a few adjacent clock hours when implanted singly.22–28 The main benefits of using this category of PIDs is the smaller corneal incision required for insertion of implant and, thus, minimal risk for intraoperative and postoperative complications.26–28 However, this type of PID is susceptible to fracture because of its brittleness, and an intact capsule bag is required for the implantation. Also, accurate alignment of the implant can be technically demanding; however, newer 50 F (Miller variant) generation of endocapsular CTR-based PID with wider segmental fins with narrower gaps between them make alignment more facile.27 Another multipiece endocapsular design from Ophtec BV (Groningen, the Netherlands) has 2 orthogonal segments and a third central locking element, and comes in 3 lights hues of green, brown, and blue (Fig. 3). This PID requires a larger incision than for phacoemulsification, although smaller than required for the full-sized devices.
Placement of the locking element, however, demands significant intraocular dexterity.29 Foldable iris diaphragms. Two foldable iris diaphragms without optics have been reported. Pozdeyeva et al.30 described a foldable elastomer device with outer springlike elements intended to stabilize it within the ciliary sulcus. This device is not yet commercially available.
Customized artificial iris
Customized artificial iris is a type of PID that consists of only the iris diaphragm without the central optic. The ArtificialIris (known in the United States as Customflex PID; HumanOptics, Erlangen, Germany) is the most commonly used type of customized artificial iris.31–34 It is made of biocompatible hydrophobic silicone elastomer and consists of an iris diaphragm without a central optic. It is custom-made (hand coloured) based on the iris colour of the fellow eye. A photograph of the normal fellow (if available) is supplied to the manufacturer to facilitate this process. The custom artificial iris has an overall diameter of 12.8 mm with a central pupillary opening of 3.35 mm (Fig. 4). It is available either without or with a polyester mesh that is incorporated within the substance of the silicone material. The latter subtype confers a better gripping to the sutures, allowing transscleral suture fixation in cases without capsulozonular stability.
Fig. 3 — Designs and models of Ophtec types of prosthetic iris devices.
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Prosthetic iris devices—Srinivasan et al. traumatic aniridia. Since then the indications of implantation of PID have extended to many other conditions. These include partial and complete congenital aniridia,6,7,11,18–20,23–25,27,35 iris coloboma,19,22,25 ocular albinism,16,18,22,28 congenital syndromic disease,23 traumatic aniridia,6,8–10,12–18,20–27,31–35 traumatic 22,26,35 mydriasis, uveitic iris damage,22,24 and iatrogenic iris defect secondary to surgery and laser treatment.10,14,16,22,25–27,30
SELECTION Fig. 4 — Custom-made artificial iris from HumanOptics.
The foldable property of silicone and the lack of central optics allow the artificial iris to be inserted via a small corneal incision (Fig. 5). The simulation of the photographed fellow iris’s appearance can produce a highly satisfactory cosmetic appearance (Fig. 4). Also, it can be combined with any type of IOLs depending on the patient’s need. However, some surgeons perceive this as a disadvantage because a separate IOL is required.
INDICATIONS DEVICE
FOR THE
USE
OF
PROSTHETIC IRIS
Sundmacher et al.6,7 first implanted the posterior chamber PID to treat patients with congenital and
OF
PROSTHETIC IRIS DEVICE
Various designs and models of PIDs are currently available in the market. This allows the operating surgeons to select the most appropriate PID for their patients with iris defect on an individual basis. Fundamentally, the selection of PID is largely dictated by a number of factors, including the phakic status, the presence of an intact capsule bag, and the severity and extent of the iris defect. Phakic status
PID can be used in phakic, pseudophakic, and aphakic eyes. In aphakic patients with or without capsular support, iris-lens diaphragm can be implanted in the sulcus without or with transscleral suture fixation, respectively. In pseudophakic patients, an endocapsular CTR-based PID can be implanted in the capsular bag after the reopening of the capsule bag with viscoelastic material. Alternatively, an IOL exchange can be performed with a secondary iris-lens
Fig. 5 — Implantation of a custom-made artificial iris (HumanOptics) during cataract surgery in an eye with inferior 180-degree iris loss. CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
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Prosthetic iris devices—Srinivasan et al. diaphragm implanted in the sulcus or within the capsule bag. In addition, a secondary sulcus implantation of ArtificialIris (HumanOptics) in pseudophakic eyes has been described in the literature. In contrast, simultaneous cataract surgery and PID implant, either with iris-lens diaphragm or endocapsular PID, can be performed in phakic patients with iris defect. Although PID has been implanted in phakic patients without simultaneous lens extraction,34,36,37 Snyder and Perez38 cautioned the use of PID in such cases because of the possibility of cataract formation or progression. Integrity of the capsule bag
The presence of an intact capsular bag serves as one of the major determining factors in the selection of PID. For instance, in patients with an intact capsular bag, an endocapsular PID can be implanted within the bag. This is the most preferable option because it has the best safety profile. Alternatively, an iris-lens diaphragm can be implanted in the sulcus or within the capsular bag. However, an intact capsule bag is frequently absent in patients with congenital or traumatic aniridia because of several reasons, including aphakia secondary to previous removal of congenital cataract,20,22,32 damage to the lens or capsule sustained from the trauma,12–14,20,22,24 or capsule damage during combined cataract surgery and PID placement. The latter is more common in congenital aniridics because of the much thinner and fragile nature of the congenital aniridic capsule.22–24 Implantation of an iris-lens diaphragm with transscleral suture fixation will be typically indicated in those patients without an intact capsule bag. Severity and extent of the iris defect
Based on the severity and extent of the iris defect, selection of the PID can be categorized into 3 groups: (i) iris defect of less than 3 clock hours, (ii) 3 to 6 clock hours, and (iii) extending more than 6 clock hours. For all the patients without an intact capsule bag, iris defects of various severities, ranging from a small colobomatous defect to total aniridia, can be corrected only with an iris-lens diaphragm PID with transscleral suture fixation. For those with an intact capsule bag and iris defect that extends more than 6 clock hours, an endocapsular CTR-based PID such as Morcher type 50 can be implanted in pair within the bag to manage the defect, whereas an endocapsular CTR-based PID such as Morcher type 96 can be used to address an iris defect of less than 3 clock hours. Depending on the surgeon’s preference, patients with an iris defect extending between 3 and 6 clock hours can be managed by either using a pair of Morcher type 50 or a pair of Morcher type 96. Cosmesis
Some patients may have greater or lesser concerns about the appearance conferred by the iris device. This may vary
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by iris colour, life philosophy, or personal body image. Black PMMA units do not alter the appearance either favourably or unfavourably. The light colours of the Ophtec devices may be a pleasant improvement for some lighter-eyed patients, whereas others may find the colour or smooth, reflective surface distracting. Custom devices seem to have the greatest likelihood of having a similar appearance to the fellow eye. In albinism, the device is covered by stroma, and thus has no cosmetic implication. We feel compelled to emphasize that this review does not address the NewColorIris, an implant that has been marketed for iris colour change in normal eyes. We are aware of no supportive reports in the world literature, although numerous authors have described severe ocular sequelae from their use.39–47
SURGICAL TECHNIQUE Operating on patients with congenital or traumatic aniridia often poses great challenges to the surgeons. In congenital cases, the potential obstacles include limited visibility because of corneal epithelial disease11,20,22 and aberrant anterior capsule fragility.22–24 Problems with traumatic cases are largely influenced by the collateral damages sustained during the ocular injury. These include poor visibility secondary to corneal scarring,12,20,22 poor red reflex caused by vitreous hemorrhage,12 zonular weakness/ dehiscence,22 and capsular rupture.22,24 Quite often, a combination of different surgical procedures is required simultaneously to manage the traumatic injury.6,10,12,15,19,21 Therefore, meticulous preoperative assessment with careful consideration of the risk and benefit of the surgery is essential. Various surgical techniques have been described in the literature in relation to implantation of different types of PID. Broadly, the surgical technique can be categorized into 3 groups, including sulcus implantation with or without transscleral suture fixation and endocapsular implantation. In this article, we present some of the exemplary techniques that have been performed in recent years. Sulcus implantation with transscleral suture fixation
A conjunctival peritomy is created along the superior limbus from 10 to 2 o’clock. A 10.0-mm-wide superior limbal incision is made; then scleral flaps are prepared at 2 and 8 o’clock for covering suture for iris-lens diaphragm IOL fixation. Viscoelastic material is injected into the anterior chamber before implantation of the IOL. Transscleral IOL fixation 1.5 mm posterior to the limbus at the level of the ciliary sulcus is performed by using 9–0 polypropylene double-arm sutures. The superior incision and the scleral flaps are then closed with 10–0 nylon sutures, and residual viscoelastic material is completely removed. Some surgeons prefer suturing variations with different incision or suture locations and may not
Prosthetic iris devices—Srinivasan et al. uniformly use scleral flaps.13,14,17,23 CV-8 Gore-Tex suture (Gore Medical, Flagstaff, AZ, USA), although not approved for ophthalmic use, also provides excellent stability and has no known biodegradation. Sulcus implantation with capsular support
Sulcus implantation with capsular support is similar to the technique for implantation of posterior chamber IOL in the sulcus with capsular support. The types of PID inserted into the eyes determine the size of corneal incision. For instance, a 3.0- to 3.5-mm corneal incision is required for ArtificialIris, whereas a minimum of 10-mm corneal incision is required for Morcher Type 67 or Ophtec 311 implants. In certain circumstances, viscoelastic materials or iris spatula can be used to lift away the iris remnants, ensuring the PID is implanted in the sulcus instead of in front of the iris or at the anterior chamber angle. However, caution needs to be taken in implanting PID in the sulcus without scleral suture fixation in view of potential risk for migration, uveitis-glaucoma-hyphema, and corneal decompensation in cases of total or near-total aniridia. Endocapsular implantation
In phakic patients, routine phacoemulsification is performed and IOL is implanted into the capsular bag.26 After the implantation of IOL, the anterior capsule is stained (if it had not been stained during the phacoemulsification). Capsule staining permits better visualization, because the red reflexes disappear as the opaque device is inserted. Trypan blue is suitable for most cases; however, we find indocyanine green (ICG; Akorn Pharmaceutical, Lake Forrest, IL, USA) more useful when implanting the black PIDs, because it also fluoresces in the red spectrum under the operative microscope.29 Furthermore, in congenital aniridics, ICG does not compromise the already fragile anterior capsule, whereas Trypan blue does reduce capsular elasticity.48,49 Subsequently, a cohesive ophthalmic viscosurgical device (OVD) opens up the potential space between the IOL and the anterior capsule. The initial corneal incision is then enlarged to accommodate the preselected endocapsular PID. With the Morcher type 50, 2 implants are sequentially inserted and dialed into position so that the fins interlock to create a complete ring. With the Morcher type 96, the implant is dialed within the bag until the single fin corresponds with the area of sectoral iris defect. Some surgeons may find it easier to implant the endocapsular PID before IOL implantation. However, in our experience, we find it easier and safer to implant the IOL first followed by the endocapsular PID as the sharp edges of the PID can rupture the capsular bag if inserted before IOL insertion. At the end of the procedure, the OVD is aspirated and corneal stromal hydration is performed to create a self-sealing wound (Figs. 6 and 7).
Fig. 6 — A, Preoperative photograph showing large superior iris defect in the right eye. B, Postoperative photograph after implantation of custom-made artificial iris from HumanOptics showing excellent cosmetic outcome.
OUTCOMES There is a considerable body of literature concerning the clinical outcomes after the implantation of PID to correct the iris defects. The main reported beneficial effects of PID implant include improved visual acuity, reduced glare and photophobia, and improved cosmetic appearance. All relevant case series reporting the clinical outcome of implantation of PID are summarized in Table 2. Visual acuity
Good visual outcome after implantation of the PID has been consistently reported in many case series (Table 2).6,7,10–32,35 The improvement of vision is attributable to various factors, including reduced spherical and chromatic aberration, increased depth of focus, and reduced glare and photophobia. Also, simultaneous cataract surgery is frequently performed during the insertion of PID, which can contribute to the improvement of visual acuity. CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
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Prosthetic iris devices—Srinivasan et al.
Fig. 7 — Implantation of a partial prosthetic iris device into the capsular bag during cataract surgery in an eye with inferior coloboma.
However, it is important to bear in mind that the Snellen visual outcome is largely influenced by the underlying cause of the iris defect and the comorbidities associated with the operated eyes. This is relevant in the context of both congenital and traumatic iris defects. For instance, Aslam et al.20 and Burk et al.22 reported better visual outcomes in the group with traumatic aniridia as compared with those with congenital aniridia after the implantation of PID. The possible explanation is that congenital aniridia is commonly associated with other ocular comorbidities such as corneal epithelial disease, glaucoma, cataract, optic nerve hypoplasia, and foveal dysgenesis. However, patients with traumatic aniridia may have associated traumatic ocular comorbidities that can affect the final visual outcome.19,27 Therefore, careful preoperative assessment with appropriate counseling before the surgery is essential. Glare
Glare remains as one of the major problems associated with iris defects. Great success of reducing glare and photophobia after implantation of PID has been reported in various studies (Table 2). Most studies11,13,15–19,22–28,31,35 reported a great improvement in the reduction of glare after the PID implantation, with a range of 75% to 100% success rate.
appearance. Various studies14,19,35 have reported good patient satisfaction of the cosmetic appearance after the implantation of PID. The recent innovation of ArtificialIris (HumanOptics) further improves the cosmetic appearance of the affected eyes via custom crafting of the device to an index photo of the normal fellow iris.31,32 However, Sikder et al.39 cautioned the use of PID in improving the cosmetic appearance as the sole purpose in view of the potential intraoperative and postoperative complications. In addition, various reports have highlighted the devastating postoperative complications concerning a specific anterior chamber cosmetic PID, namely, the NewColorIris (see later discussion). Summary
PID serves as an effective treatment modality in addressing iris defects anatomically and functionally. However, it is important to note that the quality of the evidence is not robust because the majority of the studies were of retrospective case series with lack of controls. In addition, cost of PID implants may serve as a barrier to some patients and hospitals. Further high-quality studies (i.e., randomized, controlled trials) will help elucidate the benefit and cost-effectiveness of PID implants in patients with iris defects.
COMPLICATIONS Cosmetic appearance
One of the additional beneficial effects alongside the functional benefits is the improvement of the cosmetic
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The safety of implantation of PID has been demonstrated in many studies; however, several complications
Table 2—Synthesis of case series reporting clinical outcomes and complications of implantation of prosthetic iris devices No.oftreated eyes
Author (yr)
Types of iris defect
Treatment
Types of PID
Outcomes
Sundmacher et al.6 (1994)
13
Congenital
PID þ CS ⫾ PK (2)
Morcher (67, 67B-D)
Improved VA (9, 69%)
Sundmacher et al.7 (1994) Osher and Burk24 (1999)
13
PID ⫾ CS (6) ⫾ PK (7)
Morcher (67, 67B)
Improved VA (11, 85%)
PID ⫾ CS (6) ⫾ AV (1)
Morcher (50C, 67F, 96G)
Improved VA (7/7, 100%); reduced glare (6/6, 100%)
Thompson et al.10 (1999)
7
5 congenital, 8 traumatic 4 congenital, 2 traumatic, 1 uveitic 6 traumatic, 1 iatrogenic
PID ⫾ PK (4) ⫾ AV (5)
Morcher 67G
Improved BCVA (5/7, 71%); reduced glare (1/4, 25%)
7
Complications Capsular tear (1, 8%); haptic rupture (1, 8%); suboptimal implantation site (6/26, 23%); mild prolonged AU (13, 100%); new/progression of glaucoma (4, 31%) Mild prolonged AU (13, 100%), new/progression of glaucoma (6, 46%); suboptimal implantation site (5/26, 19%) Capsular tear (2, 29%); prolonged AU (1, 14%); retinal detachment (1, 14%) Glaucoma (2)* with 1 required glaucoma surgery; retinal detachment (1, 14%); endophthalmitis (1, 14%); VH (1, 14%); implant decentration (3, 43%) New/progression of glaucoma (8, 42%); 4 (21%) required glaucoma surgery; CMO (2, 18%); ECL (3, 27%); progression of CED (4, 21%); mild prolonged AU (19, 100%); explantation of implant (2, 11%) Fractured implant (3, 11%); capsular tear (2, 7%); transient hypotony (2, 7%); mild prolonged AU (1, 4%); CMO (1, 4%), retinal detachment (1, 4%), PCO (6, 21%)
Reinhard et al.11 (2000)
19
Congenital
PID þ CS
Morcher (67, 67B/C/D/G)
Improved VA (14/19, 74%); reduced glare (11/14, 79%)
Burk et al.22 (2001)
28
12 congenital, 12 traumatic, 2 iatrogenic, 2 uveitic Traumatic
PID ⫾ CS (20) ⫾ PK (1) ⫾ GS (1)
Morcher (50C, 67F/G, 96G)
Improved VA (22/28, 79%); reduced glare (23/24, 96%)
PID þ PPV
Morcher 67G
Improved BCVA (5, 83%)
Hypotony (2, 33%); VH (1, 17%); Glaucoma (1)*
15
Traumatic
PID
Morcher 67G
Mild implant decentration/tilt (6, 20%); transient hyphema (1, 7%); VH (2, 13%); glaucoma (2)* with 1 required SLT
Beltrame et al.15 (2003)
10
Traumatic
PID ⫾ CS (2) ⫾ PK (3) ⫾ AV (7) ⫾ PPV (4)
Morcher 67F
Improved UCVA (15, 100%); improved BCVA (8, 53%); reduced glare (15, 100%) Improved BCVA (8, 80%); reduced glare (10, 100%)
Price et al.16 (2004)
10
PID ⫾ CS (1) ⫾ PK (1)
Ophtec 311
Menezo et al.23 (2005) Wong et al.18 (2005) Pozdeyeva et al.30 (2005)
9
7 traumatic, 2 iatrogenic, 1 congenital 5 traumatic, 4 congenital 4 congenital, 2 traumatic 17 traumatic, 3 congenital
PID ⫾ CS (6) ⫾ GS (2) PID ⫾ CS (3)
Morcher (67F/G, 50D, 96F), Ophtec Morcher 67, 67F
PID ⫾ CS (12) ⫾ PK (5) ⫾ PPV (4)
Customized iris-lens diaphragm
PID þ CS
Morcher (50C, 67F/G, 96G)
Omulecki and Snyder12 (2002) Dong et al.13 (2003)
6
20
Mavrikakis et al.25 (2005)
10
Srinivasan et al.26 (2007) Moghimi et al.17 (2007)
5
Miller et al.19 (2007) 28
Karatza et al. (2007) Aslam et al.20 (2008)
PID þ CS
Morcher (50C, 96F)
4
4 traumatic, 4 iatrogenic, 2 congenital 3 traumatic, 2 iatrogenic Traumatic
PID
Morcher 67G, Ophtec 311
9
Traumatic
PID þ PK
Ophtec 311
13
Congenital
PID ⫾ CS (12)
40
25 traumatic, 15 congenital
PID þ CS
Morcher 50C/D, Ophtec 311 Morcher 67F
Improved BCVA (5, 100%); reduced glare (5, 100%) Improved VA (4, 100%); reduced glare (4, 100%); improved contrast sensitivity (4, 100%) Improved BCVA (4, 44%); reduced glare (8, 89%); improved cosmesis (9, 100%) Improved BCVA (8/13, 62%); reduced glare (6/8, 75%) BCVA in traumatic cases: mean logMAR 1.34 improved to 0.54;BCVA in congenital cases: mean logMAR 1.17 improved to 1.01
New/progression of glaucoma (5, 56%) with 4 required laser/surgery; trophic corneal ulcer (1, 11%), rotatory corneal graft (1, 11%) Hyphema (1, 17%); choroidal detachment (1, 17%); persistent CED (1, 17%) VH (1, 5%); hyphema (2, 10%); prolonged AU (1, 5%); choroidal detachment (1, 5%); glaucoma (1, 5%); CMO (1, 5%); graft failure (1, 5%) Anterior capsular tear (1, 10%); mild AU (4, 40%); implant migration (2, 20%) None Implant decentration (1, 25%), glaucoma (2)*
Graft problem (2, 22%); VH (1, 11%); hyphema (1, 11%); prolonged AU (3, 33%); glaucoma (1)*; implant decentration (4, 44%) None Zonular dehiscence (1, 3%); glaucoma (12)* with 6 (15%) required glaucoma surgery; implant migration (1, 2.5%); LSCD (4/15, 27%)
13
Prosthetic iris devices—Srinivasan et al.
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Improved UCVA (9/10, 90%); reduced glare (6/6, 100%); improved photophobia (9/9, 100%) Improved VA (9, 100%); reduced glare (9, 100%) Improved BCVA (1, 17%); reduced glare (6, 100%) Improved BCVA (15, 75%); reduced glare (20, 100%); improved cosmesis (20, 100%) Improved BCVA (9/10, 90%); reduced glare (4/5, 80%)
Prolonged AU (4, 40%); glaucoma (4, 40%) with 1 required surgery; transient hyphema (4, 40%); implant decentration (2, 20%); haptic rupture (2, 20%) Prolonged AU (1, 10%); macular edema (1, 10%)
have been reported in the literature concerning eyes in which implantation of PID has been undertaken (Table 2). These complications may be related to the PID itself or the comorbidities associated with congenital and traumatic aniridia. Complications can be divided into intraoperative and postoperative complications. Intraoperative complications
*Data presented included only patients with new-onset glaucoma after operation; CMO, Cystoid macular edema; PCO, Posterior capsule opacification.
PID, prosthetic iris device; CS, cataract surgery; PK, penetrating keratoplasty; VA, visual acuity; AU, anterior uveitis; AV, anterior vitrectomy; BCVA, best corrected visual acuity; VH, vitreous hemorrhage; ECL, endothelial cell loss; CED, corneal epithelial disease; GS, glaucoma surgery; PPV, pars plana vitrectomy; SLT, selective laser trabeculoplasty; UCVA, uncorrected visual acuity; LSCD, limbal stem cell deficiency; BCGVA, best corrected glare visual acuity; IOP, intraocular pressure.
None ArtificialIris PID ⫾ PK (2) ⫾ GS (2) Traumatic 4
PID ⫾ CS (3) ⫾ GS (1) Traumatic 4
Morcher 67F/G, Ophtec 311 ArtificialIris Traumatic
Petousis et al.14 (2011) Mashor et al.21 (2011) Ayliffe et al.31 (2012) Forlini et al.32 (2013)
16
11
PID þ PK
Complications
Glaucoma (2, 13%); hypotony (2, 13%); phthisis (1, 6%); hyphema (1, 6%); implant decentration (1, 6%), silicone oil prolapse (3 of 8, 38%) Glaucoma (2)* with raised IOP requiring removal of IOL (1, 9%); graft failure (2, 18%) None Morcher (50D, 67F/G/L) PID
Improved BCGVA (13, 100%); reduced glare (10, 77%); improved cosmesis (7, 54%) Improved VA (4/11, 36%); improved cosmesis (11, 69%) Improved BCVA (9/11, 82%); reduced glare (4/9, 44%) Improved UCVA (4/4, 100%); reduced glare (3/3, 100%) VA and glare not reported; good anatomical results (4, 100%)
Outcomes Types of PID
Morcher (50D/F, 96F/S)
Treatment
PID ⫾ CS (9)
7 traumatic, 5 iatrogenic, 1 congenital Traumatic 13 Olson et al.27 (2008)
Types of iris defect No.oftreated eyes Author (yr)
Table 2 (continued )
14
Transient hyphema (1, 8%); implant malpositioning (2, 15%)
Prosthetic iris devices—Srinivasan et al.
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The most common intraoperative complications include implant-related problems, capsular tear, and hyphema. Implant-related problems. Although uncommon, broken implants have been reported in a few studies during the loading and implantation phases of the surgery.7,15,22,26 This is due to the brittleness of the implant caused by irradiation treatment of the PMMA material, which confers its black opaque appearance. Therefore, availability of a spare implant and meticulous surgical technique are important to avoid this problem. In addition, implantation of the PID at a suboptimal site may occur intraoperatively. For instance, Sundmacher et al.7 and Reinhard et al.11 reported that 6 (23%) of the 26 PID loops and 8 (21%) of the 38 loops were found to be implanted at the anterior chamber angle, on the rudimentary iris or pars plana instead of the sulcus, respectively. However, suboptimal implantation site can be overcome by implanting an endocapsular PID within the bag.22,26,27 Also, separating the rudimentary iris from the anterior capsule with the aid of OVD or iris spatula can help address this problem.31 Capsular tear. Capsular tear is uncommon during the implantation of PID, with a reported rate of 0% to 10% in most studies.7,20,22,25–27,35 The capsular tear can be related either to the implantation7,24,25 or to the aberrant fragility of the capsule in congenital aniridia.22–24 In spite of the tear, implantation of the PID within the bag or in the sulcus has been safely achieved in most cases without any additional surgical procedure.22,24,25 Hyphema. Intraoperative bleeding or hyphema can occur during the fixation of transscleral suture over ciliary sulcus,15 the posterior synechiolysis,19,27 and the implantation of PID causing traumatic injury to the iris.18 However, the intraoperative bleeding is usually transient and self-limiting. Postoperative complications
The most common complications after implantation of PID include raised intraocular pressure (IOP)/glaucoma, prolonged postoperative inflammation or anterior uveitis, secondary glaucoma, and malpositioning of the implant. intraocular pressure/glaucoma. Raised IOP or glaucoma serves as one of the most commonly reported postoperative complications after implantation of PID.6,7,10–15,17,19,21–23,25 It can present as a new-onset glaucoma or progression of previously controlled glaucoma. This is important because coexisting glaucoma is frequently observed in patients with congenital and
Raised
Prosthetic iris devices—Srinivasan et al. traumatic aniridia.6,7,11,15,21–23 Mashor et al.21 and Burk et al.22 reported that 64% and 39% of their cohort suffered from pre-existing glaucoma before the surgery. Several mechanisms have been proposed in relation to the development of glaucoma after implantation of PID. Reinhard et al.11 reported that 4 (21%) of 19 eyes developed secondary glaucoma after sulcus implantation of the iris-lens diaphragm (various Morcher 67 models). In addition, deterioration of pre-existing glaucoma was noted in 4 (80%) of 5 patients postoperatively. Two (11%) of the cases required trabeculectomy, cyclodestruction, and explantation of the PID to achieve adequate IOP control. They postulated that implantation of the PID can result in chronic alteration of the blood–aqueous barrier (BAB), accelerating the progression of glaucoma.11 This can be due to continuous irritation of the uveal remnants by the diaphragm and haptics, dislocation of the haptics into the anterior chamber angle, and inherent vulnerability of the BAB to all types of trauma in congenital aniridic eyes.11 In contrast, Aslam et al.20 reported an increased prevalence rate of glaucoma from 25% to 40% after sulcus implantation of the iris-lens diaphragm (Morcher 67F). More interestingly, they found that the mean IOP rise occurred within 2 to 3 weeks after the surgery and required IOP-lowering medical or surgical treatment within a year. This suggested that the raised IOP is most likely secondary to the direct mechanical effect of the large iris-lens diaphragm with rigid haptic, either by obstructing the aqueous flow or by compressing the trabecular meshwork. Based on the proposed mechanisms, it is reasonable to hypothesize that the risk for development of glaucoma can be reduced or eliminated by implanting the PID within the bag because it avoids any mechanical pressure or irritation to the uveal tissues and trabecular meshwork. The minimal risk for postoperative glaucoma after implantation of endocapsular PID has been demonstrated in several studies.25–28 Prolonged postoperative inflammation after implantation of PID has been reported in a few studies.6,7,11,24,25 Sundmacher et al.6,7 and Reinhard et al.11 reported that all of their patients experienced a mild persistent intraocular inflammation or anterior uveitis after the implantation of PID. Sundmacher et al.6 suggested that the postoperative prolonged intraocular inflammation might be secondary to the suboptimal positioning of the PID. However, following the improvement of instrumentation and surgical techniques, prolonged postoperative intraocular inflammation has become a lesser problem.13,16,22,24,26,35 Prolonged inflammation/anterior uveitis.
Instability of the PID after the implantation has been reported in some studies.10,13– 15,17,19,20,25,27 However, the extent of decentration, migration, or tilting of the PID was mild in most cases, and further surgical intervention to reposition or realign the PID was rarely required.15 Malpositioning of the implant
Malpositioning of the implant.
is usually observed in patients who received iris-lens diaphragm PID that required transscleral suture fixation. This is because there is lack of mechanical support to the PID (e.g., no capsular support, vitrectomized eye), and some of the iris-lens diaphragms have only 2 fixation points for transscleral suturing. Having a 3-point fixations implant can potentially ameliorate the problem. Although uncommon, Mavrikakis et al.25 reported migration of endocapsular PID in 2 (20%) of the 10 patients caused by anterior capsular tear and capsular contraction in each eye. Other postoperative complications have been noted after implantation of the PID. These include progression or development of corneal epithelial disease in congenital aniridic eyes.11,18 This is fully expected in view of the genetically defined progression of stem cell failure in this cohort with or without intervention. Vitreous hemorrhage,10,12,13,35 retinal detachment,10,22,24 choroidal detachment,18,35 hypotony,12,14,22 endophthalmitis,10 and cystoid macular edema11,22,35 are other reported complications, although they may have similar incidence in eyes that have similar surgeries without a PID.
Other postoperative complications.
COSMETIC IRIS DEVICES: MISUSE COMPLICATIONS
AND
In recent years there has been an increasing concern regarding the long-term safety of specific cosmetic iris devices, namely, NewColorIris (Kahn Medical Devices, Panama City, Panama).39 Hyphema, raised IOP, reduced vision, and corneal edema were the common complications reported.39–47 It has been proposed that these complications are attributed to the direct contact between the implant and the angle structures,41,42,45 and the surface and edge irregularities of the implants causing abrasion to the iris and corneal endothelium.40,42 It is important to distinguish between this discredited device and the reputable devices described earlier.
CONCLUSIONS PID serves as an effective and safe treatment modality in managing patients with iris defect of different underlying pathologies. Promising outcomes, including improved vision, reduced glare, and improved cosmetic appearance, have been reported in many studies. However, meticulous preoperative assessment with judicious selection of appropriate candidates is essential to achieve the best outcome after implantation of PID. Specific guidelines on the selection criteria for patients receiving PID implantation will be useful for the surgeons in the future. We recommend the use of endocapsular PID implant, when it is possible, over the anterior chamber or sulcus PID implants in view of the lesser risk for complications. CAN J OPHTHALMOL — VOL. 49, NO. 1, FEBRUARY 2014
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Prosthetic iris devices—Srinivasan et al. Future studies with longer-term follow-up period are required to elucidate the long-term effect of PID implants.
Disclosure: The authors have no proprietary or commercial interest in any materials discussed in this article. Dr. Michael Synder is an consultant for Human Optics. Literature Search: Electronic databases including MEDLINE and EMBASE were searched, reference lists were hand-searched, and experts in the field were contacted to identify peer-reviewed literature concerning PID. Only articles written in English were included in this review. Certain keywords were used during the literature search, including PID, artificial iris, and iris reconstruction.
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