Visual outcome after surgery for Peters' anomaly

Peters Anomaly: Novel Non-Invasive Alternatives to Penetrating Keratoplasty

BACKGROUND

Peters' anomaly (PA) is the most commonly encountered congenital corneal opacity (CCO) and displays a wide phenotypical range. The relatively recent adoption of high-quality anterior segment imaging in the form of high-frequency ultrasound biomicroscopy and anterior segment optical coherence tomography has aided in the accurate diagnosis of CCOs, facilitated distinction of PA from "pseudo-Peters' anomaly," and aided in prognostication and surgical risk stratification in PA. While the definitive management of PA, especially the more severe forms, is penetrating keratoplasty (PK), long-term success rates have overall been disappointing. This spurred the development of more non-invasive procedures, such as optical iridectomy and the more recently described selective endothelial removal, which represent viable alternatives to PK, at least in the less severe phenotypes of PA.

METHODS

Literature searches for the components of this review were performed using PubMed, in September 2021. The following keywords and their iterations were employed for the searches: "Peters' anomaly," "anterior segment dysgenesis," "kerato-irido-lenticular dysgenesis," "congenital corneal opacities." These were entered into the PubMed search engine, revealing 2852 related articles. The inclusion criteria included publications in the English language, specific to Peters' anomaly. Fifty-five studies that were published as systematic reviews or as nonrandomized comparative studies (cohort or case series) on the topic of Peters' anomaly were finally selected for this review.

RESULTS

This review provides a summary of Peters' anomaly in the context of advances in diagnosis, classification, and genotype-phenotype correlation of congenital corneal opacities, with a focus on penetrating keratoplasty, its outcomes, and non-invasive surgical options. While conservative therapies such as spontaneous clearing, mydriatic eye drops, and optical iridectomy may have variable success in milder variants of PA, penetrating keratoplasty in these eyes is fraught with several challenges and typically results in poor long-term functional outcomes. The management strategy depends on several variables such as phenotypical severity of PA, laterality, age at presentation, and capacity to adhere to the follow-up schedule. Notwithstanding the choice of treatment, it is essential that early and aggressive amblyopia therapy, a thorough systemic examination, and appropriate referral are undertaken for all patients of PA.

CONCLUSION

Peters' anomaly has seen recent advances in diagnosis, but treatment options remain limited. Focus directed towards less-invasive alternatives to keratoplasty may yield better functional outcomes.

Selective Endothelialectomy in Peters Anomaly: A Novel Surgical Technique and Its Clinical Outcomes in Children

PURPOSE

This study describes the surgical outcomes of selective endothelialectomy in Peters anomaly (SEPA), a relatively new technique to manage Peters anomaly (PA).

METHODS

This study included 34 eyes of 28 children who had a visually significant posterior corneal defect due to PA and underwent SEPA between 2012 and 2019. A selective endothelialectomy from the posterior corneal defect was performed while preserving Descemet membrane. The primary outcome measure was the resolution of corneal opacification. The secondary outcome measures were functional vision, complications, and risk factors for failure.

RESULTS

At a mean postoperative follow-up of 0.96 ± 0.20 years, 29 eyes (85.3%) maintained a successful outcome. Mean preoperative and postoperative best-corrected visual acuities were 2.55 ± 0.13 and 1.78 ± 0.13 ( P < 0.0001), respectively. Ambulatory functional visual improvement was seen in 97%, and 23% attained vision ranging between 20/190 and 20/50. Corneal opacification failed to clear in 5 eyes (15%). Risk factors associated with surgical failure were female sex ( P = 0.006), disease severity ( P < 0.0001), glaucoma ( P = 0.001), and additional interventions after SEPA ( P = 0.002). In multivariate analysis, only disease severity (ie, a type 2 PA) was a significant risk factor for the failure of SEPA. There were no sight-threatening complications.

CONCLUSIONS

SEPA is a safe and effective technique in select cases of posterior corneal defect due to PA. SEPA could be a potential surgical alternative to pediatric keratoplasty or optical iridectomy in children with central corneal opacification smaller than 7 mm due to PA.

Possible association between viral infection and poor survival of the corneal graft after penetrating keratoplasty in patients with congenital corneal opacity: a cohort study

BACKGROUND

Congenital corneal opacity (CCO) is a rare disorder. Penetrating keratoplasty (PK) is the main surgical option for CCO, but many factors affect graft survival. Therefore, this study aimed to perform a virological examination of CCO specimens after PK to explore the relationship between virological factors and graft survival after PK.

METHODS

This prospective study included consecutive patients (<6 months of age) diagnosed with CCO and treated with PK at Beijing Tongren Hospital from August 2017 to January 2018. Next-generation sequencing was used to detect viral DNA in the CCO specimens. The survival of the primary graft was analysed using the Kaplan-Meier method.

RESULTS

Overall, 24 eyes of 24 infants were treated with PK during the study period. The mean age at surgery was 4.8±1.1 months. Epstein-Barr virus DNA was detected in two specimens, varicella-zoster virus DNA in one specimen, herpes simplex virus DNA in three specimens and cytomegalovirus DNA in one specimen. In the virus-positive group, only one (14.3%) graft remained clear during follow-up. In contrast, in the virus-negative group (n=17), 13 (76.5%) grafts were still clear at the last follow-up. The mean survival of the grafts in the virus-positive group was significantly shorter than in the virus-negative group (11.0±9.8 months vs 27.1±7.7, p<0.001).

CONCLUSION

The presence of viral DNA in CCO specimens might be associated with poor graft survival after PK.

Visual Outcomes in Pediatric Patients with Peters Anomaly

Purpose

This study aimed to evaluate the visual outcomes of pediatric patients diagnosed with Peters anomaly (PA) in a tertiary eye care center.

Methods

This was a retrospective study undertaken at a single academic center. Clinical records of pediatric patients diagnosed with PA from 2000 to 2017 were reviewed. Parameters recorded included visual acuity (VA), intraocular pressure (IOP), presence of glaucoma, and surgical procedures performed. The impact of PA type on final visual acuity levels was analyzed using generalized estimation equation models.

Results

Twenty-one eyes from 11 patients were analyzed. At the final visit, 9 eyes (42.8%) had a VA ≥20/200, while 12 (57%) had <20/200, ranging from 20/250 to no light perception. Of the study cohort, 15 (71.5%) eyes had type I, while six (28.5%) had type II PA. Glaucoma was present in 20 eyes (95%) at the final visit. One eye had dense central leucoma and microphthalmos where IOP could not be measured accurately. Seventeen eyes (81%) underwent at least one intraocular surgery, while the average number of surgeries per eye was 2.9 ± 2.5 (range=0– 9). The type of PA beta(se)=0.53 (0.41), p = 0.20] was not found to be a significant risk factor for worse VA.

Conclusion

Severe visual impairment develops in the majority of patients with PA. The type of anomaly does not appear to be associated with a worse visual function in patients with PA. Glaucoma develops in a high percentage of this patient population, and thus close monitoring of IOP in this patient population is crucial.

Peters anomaly in a red kangaroo (Macropus rufus)

A 10-mo-old female red kangaroo (Macropus rufus) presented with a unilateral congenital corneal opacity OD. Complete ophthalmic examination revealed a shallow anterior chamber and a focal area of corneal edema with multiple persistent pupillary membranes extending from the iris colarette to the corneal endothelium adjacent to the edematous area of cornea. High-resolution B-scan ultrasound of the anterior segment showed an area consistent with thinning of Descemet's membrane in the area of corneal edema. Ophthalmic examination and ultrasound findings are consistent with a diagnosis of Peters anomaly, a form of anterior segment dysgenesis. An electroretinogram performed on the affected animal did not reveal any specific abnormalities. Karyotype analyses revealed a normal diploid number (2n = 20, -XX), with an abnormal pericentric inversion in the second largest chromosomal pair. The kangaroo exhibits mild compensated vision deficits in the affected eye. The maternal and paternal adult pairing has been discontinued in an effort to prevent future offspring anomalies.

The outcomes of primary pediatric keratoplasty in Singapore

PURPOSE

To evaluate the long-term corneal graft survival and risk factors for graft failure in pediatric eyes.

DESIGN

Retrospective, interventional consecutive case series.

METHODS

Unilateral eyes of 105 patients aged 16 years and below were included from the Singapore Corneal Transplant Study between April 4, 1991 and April 4, 2011. Corneal graft survival was calculated using Kaplan-Meier survival analysis, and survival distributions were compared using log-rank test.

RESULTS

Mean recipient age was 8.38 ± 5.63 years (range 0.18-15.92 years). Mean follow-up time was 34.16 ± 39.10 months. Main diagnoses were corneal scar (22.9%), limbal dermoid (21.9%), anterior segment dysgenesis (15.2%), and keratoconus (14.3%). Forty-four eyes (41.9%) underwent penetrating keratoplasty (PK), 37 (35.2%) underwent anterior lamellar keratoplasty (ALK), 22 (21.0%) underwent lamellar corneal patch graft, and 2 (1.9%) underwent Descemet stripping automated endothelial keratoplasty (DSAEK). Kaplan-Meier survival rates for PK were 92.8% at 1 year, 88.9% at 2-4 years, and 80.9% at 5-16 years; survival rates for ALK were 88.0% at 1 year and 84.3% at 2-7 years; survival rates for corneal patch graft were 100% at 1-3 years and 90% at 4-10 years; these were not statistically significant (P = .362). Deep corneal vascularization (P = .012), preexisting active inflammation (P = .023), preexisting glaucoma drainage device (P = .023), and preexisting ocular surface disease (P = .037) were associated with reduced graft survival in a univariate analysis.

CONCLUSIONS

We report good long-term graft survival following pediatric keratoplasty for various indications. Lamellar keratoplasty, when indicated, should be the procedure of choice in high-risk keratoplasties.

Peters' anomaly

While conducting medical aid in Mozambique, a 41 year old African male presented to our eye clinic complaining of visual impairment. The male was found to have Peters’ anomaly type 2, a rare congenital ocular malformation leading to sensory amblyopia and glaucoma.

Should unilateral congenital corneal opacities in Peters' anomaly be grafted?

PURPOSE

To evaluate the surgical outcomes and visual results after penetrating keratoplasty for congenital unilateral corneal opacities in Peters anomaly.

METHODS

This was a retrospective study of 14 children who underwent keratoplasty for a unilateral Peters anomaly between 1999 and 2009. All patients received a topical treatment of cyclosporine and corticosteroids. Suture ablation was performed between the first and second postoperative month and all patients had spectacle correction and amblyopia treatment. Age at time of surgery, posterior segment status evaluated by ultrasonography, axial length, preoperative intraocular pressure, fellow eye status, mean follow-up time, early and late complications, final graft outcome, refraction, and visual acuity upon the last visit were noted.

RESULTS

Mean age at the time of surgery was 9 months. Posterior segment was normal in all cases. Mean axial length was 18 mm and mean intraocular pressure was 11 mmHg. Mean follow-up was 30 months. Four children had graft rejection episodes, 2 of which responded to medication. Four underwent cataract surgery, one developed pupil deformation requiring a pupilloplasty, and 2 cases were complicated by surgical glaucoma. A total of 11 eyes (78.6%) had clear grafts at the end of the follow-up. Mean spherical equivalent was -1.5 D. Visual acuity was measurable in 3 cases and was 20/50 in one case, 20/63 in the second, and 20/2000 in the third. Concerning preverbal children, central, steady, and maintained fixation was found in 8 cases.

CONCLUSIONS

Operating on a unilateral congenital corneal opacity is a challenging decision and should be taken after explaining the need for long-term follow-up to the parents. Useful vision can be achieved and maintained after strict amblyopia therapy. A multidisciplinary ophthalmologic follow-up is necessary.

Long-term visual outcome of penetrating keratoplasty in infants and children with Peters anomaly

PURPOSE

To determine the long-term visual outcome of penetrating keratoplasty for Peters anomaly and to identify prognostic factors affecting final vision.

METHODS

The records of children 12 years of age or younger who underwent penetrating keratoplasty for Peters anomaly between January 1, 1971 and December 31, 1992 at Emory University were reviewed. Characteristics of the recipient, eye, donor, and surgical procedure were examined with the use of multivariate analyses.

RESULTS

One hundred forty-four keratoplasties in 72 eyes of 47 children who were followed for a minimum of 3 years from the date of first keratoplasty (median, 11.1 years) were reviewed. Visual acuities ranged from 20/25 to no light perception. Twenty-nine percent of eyes achieved 20/400 or better visual acuities, whereas 38% had light perception or no light perception. Stromal vessels (p < 0.001) and larger donor corneas (p < 0.001) were independent predictors of poor outcome. Postoperative complications included graft failure (n = 44), cataract (n = 15), glaucoma (n = 14), retinal detachment (n = 16), and phthisis (n = 22). More than half of the eyes (n = 18) without graft failure, retinal detachment and/or phthisis saw 20/400 or better.

CONCLUSIONS

Less than one-third of eyes with Peters anomaly undergoing keratoplasty achieved a visual acuity of 20/400 or better. Stromal vessels and large corneal grafts (>or=8 mm) were the only independent predictors of a poor visual outcome.

Long-term visual prognosis in children after corneal transplant surgery for Peters anomaly type I

PURPOSE

To evaluate the long-term visual prognosis in children with corneal transplant surgery for Peters anomaly type I.

DESIGN

Retrospective review of interventional case series.

METHODS

Twenty-four children treated in a university-based practice were divided into two groups for analysis: a younger preverbal group and an older group of children three years of age or older. Children underwent corneal transplantation surgery (penetrating keratoplasty [PKP]) for Peters anomaly type I as infants (age range, two to 18 months). Visual acuity using Snellen or Allen charts and glaucoma and other complications were tabulated.

RESULTS

Twenty-four patients had Peters anomaly; 16 had unilateral disease, eight had bilateral disease. Thirty eyes underwent PKP. Average age at PKP was five months. The mean follow-up from PKP to the most recent visit was 78.9 months. Fifteen eyes (50%) were treated for glaucoma. Five transplants (17%) had graft rejection episodes; two of these failed and were regrafted. Six eyes (20%) required cataract surgery. One eye had a retinal detachment. Currently, 27 eyes (90%) have clear grafts. In the younger group of children, five of six grafts are clear (83%). In the older group of 24 eyes of verbal children, seven eyes (29%) have visual acuity ranging from 20/20 to 20/50, six (25%) have visual acuity ranging from 20/60 to 20/100, nine (38%) have visual acuity ranging from 20/200 to counting fingers, and two eyes (8%) have visual acuity of hand movements. In this group, nine of 12 eyes without glaucoma had visual acuity better than 20/100; only four of 11 eyes with glaucoma were better than 20/100.

CONCLUSIONS

Many children with PKP for Peters anomaly type I can experience good or functional vision in their operated eye. Children with glaucoma have a poorer visual prognosis.

Strabismus and amblyopia in bilateral Peters anomaly

BACKGROUND

Peters anomaly is a rare form of anterior segment dysgenesis in which abnormal cleavage of the anterior chamber occurs at the end of the third week of gestation. We examined the prevalence of strabismus and amblyopia and analyzed predictive factors for their development, as well as the visual outcome and associated anomalies in patients with bilateral Peters anomaly.

METHODS

Using a retrospective review, we identified 25 consecutive patients with bilateral Peters anomaly who were observed between August 1995 and February 2005. Ocular structural and systemic anomalies, amblyopia therapy, visual acuity, and binocular alignment at last visit were recorded. Fisher's exact test was used to identify any association between defined predictive factors and the development of strabismus.

RESULTS

Mean follow-up time was 5.1 year (range, 0.5-21 years). Median age at presentation was 2.5 months (range, 1 day to 13 years). Penetrating keratoplasties were performed on 34 eyes in 20 patients. Final best-corrected visual acuity ranged from 20/25 to no light perception. Thirteen of 18 patients with recorded motility (72%) developed strabismus: esotropia (n = 7), exotropia (n = 5), and variable (n = 1); one also had dissociated vertical deviation. Patients with equal vision were either orthophoric (n = 4) or had intermittent esotropia (n = 1), whereas strabismus occurred in 100% of patients whose vision was asymmetric by more than 1.5 octaves. Asymmetric vision was the only statistically significant predictive factor for the development of strabismus (P = 0.002). Amblyopia treatment resulted in improved vision in 3 of 5 patients.

CONCLUSION

Strabismus occurs frequently in bilateral Peters anomaly. Asymmetric vision, (because of ocular structural anomalies) postoperative complications, and amblyopia may predispose to strabismus. Despite ocular structural limitations, amblyopia therapy is recommended in the aggressive rehabilitation of these eyes.

Management of intracorneal bleb after trabeculectomy for congenital glaucoma

PURPOSE

Congenital glaucoma is a well-recognized entity that can occur in the presence of anterior segment dysgenesis. Trabeculectomy is an accepted intervention in the management of congenital glaucoma. The surgical technique as well as complications is well described.

METHODS

This is a case report of a 3-month-old girl with anterior segment dysgenesis and glaucoma. She was referred post-trabeculectomy with persistent corneal opacity to be considered for penetrating keratoplasty and was found to have intrastromal corneal bleb.

RESULTS

Ultrasound biomicroscopy confirmed communication of the corneal bleb with the anterior chamber, and the bleb was treated by autologous blood injection at the trabeculectomy site, under acetazolamide cover.

CONCLUSIONS

We present evidence suggesting that abnormal structure was the etiologic basis for corneal bleb formation and describe our management of this previously unreported complication of trabeculectomy.

Congenital Corneal Opacities in a Cornea Referral Practice

PURPOSE

To address the primary causes of the congenital corneal opacities seen on the Cornea Service at Wills Eye Hospital (Philadelphia, PA), the associated systemic anomalies and their management.

METHODS

Retrospective review of the medical records of all patients with the diagnosis of congenital corneal opacities seen at the Cornea Service from January 1, 1992 to June 30, 2003. Children 12 years old or younger at the first visit to our department were included in the study. We classified the location and extent of corneal pathology. We divided the management into medical and surgical.

RESULTS

Seventy-two eyes of 47 patients were included in the study. The mean follow-up time from the first to the last visit was 33.1 months. The most common primary cause of congenital corneal abnormalities was Peters anomaly (40.3%), followed by sclerocornea (18.1%), dermoid (15.3%), congenital glaucoma (6.9%), microphthalmia (4.2%), birth trauma, and metabolic disease (2.8%). Seven eyes (9.7%) were classified as idiopathic. Ten patients had systemic abnormalities associated with their ocular condition. The management was medical in 38 eyes (52.7%). Twenty-four eyes (32.4%) underwent only 1 penetrating keratoplasty (PK). Only 1 eye received a regraft during the follow-up period. Eight grafts failed during the follow-up period.

CONCLUSION

The importance of this study is to share our experience with this rare entity, congenital corneal opacities, describing their clinical presentation and their management.

Penetrating keratoplasty in children: visual and graft outcome

AIMS

To review factors affecting graft survival and determinants of visual acuity after penetrating keratoplasty in children.

METHODS

All cases of penetrating keratoplasty performed in an ophthalmic unit, in children aged less than 15 years at the time of operation, for the period 1984 to 2002 were included.

RESULTS

19 penetrating keratoplasties were done in 18 eyes of 16 children, age range 2 weeks to 14 years 8 months (mean 9.24 years), with mean follow up 6.6 years. 73.7% of grafts have remained clear for up to 14 years. Postoperative visual acuity among congenital indications for graft was better than 6/60 in only 14.2% of cases, but was better than or equal to 6/12 in all cases of keratoconus.

CONCLUSION

This series shows that prolonged corneal graft survival can be achieved in children, but successful restoration of visual acuity depends upon a period of normal visual development before the onset of corneal opacification.

Penetrating keratoplasty in infancy and early childhood

Penetrating keratoplasty in infants and young children is performed on an infrequent basis. The most common indication is visually significant congenital corneal opacity. Surgery must be performed early to avoid amblyopia. Surgical techniques differ from those used in adult penetrating keratoplasty because of the reduced ocular rigidity encountered in infants and young children. Use of a multispecialty team approach is important to improve visual outcome. Poor prognostic indicators include bilateral disease, concomitant infantile glaucoma, lensectomy and vitrectomy at the time of surgery, previous graft failure, extensive goniosynechiae, and extensive corneal vascularization. Prompt postoperative optical rehabilitation, combined with occlusion therapy when appropriate, is an important determinant of success.

Corneal transplantation in children with Peters anomaly and mesenchymal dysgenesis. Multicenter Pediatric Keratoplasty Study

OBJECTIVE

The purpose of the study is to describe graft and visual outcomes of penetrating keratoplasty among young children with Peters anomaly and associated mesenchymal dysgeneses.

DESIGN

The design was a multicenter retrospective analysis of the indications and outcome in pediatric keratoplasty.

PARTICIPANTS

The records of all children aged 12 years and younger who underwent penetrating keratoplasty for mesenchymal dysgenesis between January 1975 and May 1993 at the participating centers were reviewed.

MEASURES

The data were analyzed regarding graft survival and postoperative visual acuity.

RESULTS

Forty-seven corneal transplants in 36 eyes of 29 patients with mesenchymal dysgenesis were studied. The majority of eyes operated on (30) had Peters anomaly (83%). Patients' mean age at the time of keratoplasty was 7 months. After a mean follow-up period of 38 months, 61% of eyes retained full graft clarity. One and 3-year survival rates were 79% (95% confidence interval [CI] = 65%-93%) and 62% (95% CI = 45%-79%), respectively. Postoperative corneal ulcers/nonhealing epithelial defects (P = 0.03), and additional noncorneal surgical procedures at the time of transplantation (P = 0.05) were associated with graft failure. Provision of postoperative optical aids (P = 0.01) was associated with better postoperative visual acuity levels.

CONCLUSIONS

Penetrating keratoplasty for Peters anomaly and related mesenchymal dysgeneses in young children has a reasonable chance of success during the critical years of visual maturation and is associated with satisfactory visual results in one third to half the cases. The data suggest that complicated cases requiring additional surgical procedures have a worse prognosis.