110 Optical Iridectomy as An Alternative Clear Visual Axis for Peters Anomaly LITERATURE REVIEW Optical Iridectomy as An Alternative Clear Visual Axis for Peters Anomaly Laura Agnestasia Djunaedi1, Julie Dewi Barliana2 1Medika Farma, Namlea, Indonesia 2Pediatric Ophthalmology Divison, Department of Ophthalmology University of Indonesia, Jakarta, Indonesia E-mail: [email protected] ABSTRACT Introduction and objective: Peters anomaly is a rare congenital disease presented with central leukoma, iridocorneal adhesion, and with or without a cataractous lens. The presence of central leukoma will block the visual axis and lead to a disruption in normal visual development. Therefore, optical iridectomy, which can overcome the high incidence of graft failure in penetrating keratoplasty (PK), has been proposed as the alternative treatment to clear the visual axis. This study aims to show the outcome of optical iridectomy in patients with Peters’ anomaly. Method: Systematic literature searched in Pubmed, Google Scholar, and Cochrane from their inception to August 2020 was conducted using keywords “iridectomy” and “Peters’ anomaly”. Full- text articles in English that report the outcome of iridectomy in Peters’ anomaly were included, and a manual review of article bibliographies was done. Outcome measures were analyzed using the following clinical questions: indication, age, visual acuity (VA), and intraocular pressure (IOP). Result: One case series and two case reports demonstrating the use of optical iridectomy in Peters anomaly were identified. In total, 26 patients aged one week to 7.7 years received optical iridectomy to establish a clear visual axis. All studies showed an improvement in visual acuity through clinical findings, and one of the studies showed a better postoperative VA in bilateral cases. Studies showed good control of IOP. Conclusion: Optical iridectomy can be used as a safe procedure to improve visual acuity in Peters anomaly patient. Keywords: anterior segment dysgenesis, optical iridectomy, peters anomaly eters anomaly is one of the concerning one is the high incidence of congenital anomalies that affect the graft failure.1,3-5 Therefore, optical P anterior segment of the eye resulting iridectomy was proposed as an alternative in central cornea opacities and other treatment. The aims of this study is to anterior segment disruption.1 Central know the outcome and complication of corneal opacities will block the visual axis optical iridectomy in patients with Peters which in turn will disrupt the normal anomaly. visual development. Thus, immediate treatment is necessary to prevent sensory METHODS ambliopia. To this day, the most commonly performed surgery to treat the Literature search was conducted central leukoma is penetrating keratoplasty.2 However, this technique still through Pubmed, Google Scholar, and has several shortfalls, and the most Cochrane from their inception to August Ophthalmol Ina 2021;47(1):110-114 111 2020 using keywords “iridectomy” and complications. Nevertheless, those with “Peters anomaly”. Randomized control previous glaucoma surgery still used their trials, cohort studies, case reports, and case glaucoma medications. series related to the outcome of optical The second study, which is the iridectomy in patients with Peters anomaly largest study was done by Spierer et al. in were retrieved. Article bibliographies were 2018. The study included 22 patients (29 manually reviewed to find the other eyes), and the mean age at the time of relevant studies. surgery was 15.6 ± 26.3 months. The The abstract and full-text studies in opacity involved the central visual axis, English were evaluated, and reports that and no red-reflex was observed did not fulfill the objective of the study preoperatively in all of the patients. were excluded. The data of study design, Optical iridectomy was most commonly indication, and age were gathered as performed in the temporal area with a demographic data, while visual acuity and minimum three-hour-clock sized. Post- intraocular pressure were included as a operatively, 98.6% (28 eyes) showed a red marker of improvement. Any adverse reflex. One patient who did not show a red effects related to the procedure were also reflex undergoes another temporal noted. iridectomy. At the long-term follow-up, around eight months to 72 months post- RESULT surgery, three of those who had a red reflex need to undergo another surgery. Three articles in English illustrating Two of them having penetrating the outcome of optical iridectomy in Peters keratoplasty, and one of them having anomaly were identified. In total, 35 eyes keratoprosthesis. The improvement in the from 26 patients underwent optical mean visual acuity (VA) was statistically iridectomy to treat their leucoma. The age significant (p<0.001). Furthermore, the of patients was ranged from one week to postoperative visual acuity improved 7.7 years (Table 1). Out of the total significantly on bilateral disease (p<0.05). articles, two case series, and one case However, three eyes (10.3%) showed report, all showed the same indication, deterioration. Pre-operative mean IOP was which is Peters’ anomaly type I with a 23.8 ± 20.3 mmHg (range 6 – 89 mmHg) clear peripheral cornea. and decrease to 20.8 ± 6.3 mmHg (range A study by Zaidmann et al. was done 12 – 34 mmHg) postoperatively (p=0.07). in three patients, ranging from 10 weeks There are no sight-threatening old to five months old, who had complications found after the surgery. paracentral corneal opacities. Two of those Nevertheless, on the last follow-up, five had undergone trabeculectomy prior to patients were diagnosed with glaucoma. optical iridectomy. At the last follow-up, A single case report of bilateral iridectomy all patients maintained a clear visual axis, was published by Chang et al. The optical as the examiner can have a good view of iridectomy was done in the temporal area patients’ fundus. However, the ability to of a 4-week-old male infant. Six months after the operation, both eyes showed a fixate and follow was only reported in two good fundus reflex and able to fixate and patients. All patients showed a normal IOP follow. Postoperative IOP was not stated, post-operatively and healed without any 112 Optical Iridectomy as An Alternative Clear Visual Axis for Peters Anomaly and complication was not found in this layers of the recipient's cornea will be study. changed with the donor’s cornea. However, performing this technique in an DISCUSSION infant's eyes is more challenging than in adult eyes, and pediatric PK requires Worldwide data showed that there is significant resources in the postoperative only 2.2 incidence of congenital corneal period, including biweekly examination opacities in 100.000 births affecting visual under anesthesia and high-dose of topical development, and Peters anomaly took the 2,9,10 steroid. Furthermore, in Peters largest proportion, around 1.5 per 100.000 anomaly, this treatment needs to be done newborns.2 There are two types of Peters before one-year-old, and studies showed anomaly, type I characterized by a central that the younger the infant underwent the corneal opacity with iridocorneal adhesion, PK, the higher the incidence of graft and type II is comprised of central corneal 2,4,5 failure. Another drawback is the high opacity with cataract or corneolenticular incidence of glaucoma, occurring in up to adhesion. In addition, those with systemic 20 - 70% in patients with Peters anomaly, anomalies (cleft lip, short stature, which will negatively affect the success abnormal ears, and mental retardation) and rate of PK.2,9,11 Study by Lucy et al. gave either Peters anomaly type I or type II additional information about the lower were included in Peters plus syndrome.1 survival probability for the second and Like other congenital anomalies that rarely 8 subsequent grafts. Thus, the timing of the stand alone, Peters anomaly also surgery is crucial. The delayed timing of associated with several ocular PK will increase the graft survival, but at abnormalities, and most commonly were the same time it will also increase the microphthalmia, coloboma, and 4,5 6 incidence of amblyopia. glaucoma. Rotating corneal autograft was The most concerning problem in proposed as an alternative treatment to Peters anomaly is the visual deprivation treat corneal opacities due to its ability to secondary to central corneal opacity. It overcome the high incidence of graft will disrupt the normal visual development rejection in PK. This technique has a lower resulting in sensory deprivation incidence of graft rejection because the amblyopia. Therefore, it is crucial to treat affected cornea of the patients will be the central corneal opacity before one- changed with the clear peripheral cornea year-old, as the first year of life is the most from the patients themselves. However, sensitive period for developing only a few patients are suitable for this amblyopia.7 Hitherto, there are several technique, as it needs a minimum diameter treatments, both pharmacological and 12 of 4 – 5 mm of the unaffected cornea. surgeries, that have been used to create a Thus, this technique cannot be used as an clear visual axis in those with central alternative treatment in a patient with corneal opacities. Peters anomaly, who usually has a large Penetrating keratoplasty (PK) was corneal opacity. the most commonly performed surgery in Pharmacological treatment using a patient with central corneal opacities that phenylephrine 1% can be used as an affect every layer of the cornea, like in alternative treatment in a small central Peters anomaly.8 In this procedure, all Ophthalmol Ina 2021;47(1):110-114 113 leucoma before the definitive treatment, term outcome of visual acuity and adverse penetrating keratoplasty, took place. It will effect is still needed. dilate the pupil, and the clear area surrounding the opacity will serve as a CONCLUSION clear visual axis. However, strong adherence is mandatory while using A clear visual axis, preferably before phenylephrine because it has to be used one-year-old, is mandatory in patient with three times a day.