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

General Treatment and Ophthalmic Management of Peters' Anomaly

Peters' anomaly (PA) is a manifestation of complex disorders in the development of the anterior segment of the eye. The most recognizable feature of the disease is a doughnut-shaped central corneal opacity and adhesions between the opacity and underlying iris. Glaucoma is observed in 30-70% of patients, with up to 50% of the patients showing concomitant vision-threatening disorders. Up to 60% of patients have systemic abnormalities or developmental delays. Being a rare malformation, PA is one of the most common congenital indications for corneal transplantation in infants. Penetrating keratoplasty is used as the primary method of treatment in cases with corneal opacification of a degree that forbids visual development in both eyes. The heterogeneity of co-occurring ophthalmic and systemic malformations in the spectrum of PA determines the wide range of success, defined by various endpoints: graft clarity or visual acuity. Although surgical advancement has made corneal grafting possible in younger children, it has a higher graft failure rate and worse visual prognosis than adult keratoplasty. Optical sector iridectomy, pupil dilation, or cornea rotation can alternatively be performed. Satisfying results of pediatric keratoprosthesis in particular cases of PA have been described. Postoperative treatment of PA aims to maintain a clear optical pathway and prevent amblyopia. This article therefore aims at reporting the ophthalmic treatment and need for multidisciplinary management of PA, including pharmacological and surgical treatment.

Peters anomaly: An overview

Peters anomaly (PA) is a rare, often bilateral, congenital corneal opacity, usually with a sporadic inheritance pattern, characterized by corneal opacities and irido-corneal or lenticular-corneal adhesions with a defect in the Descemet's membrane, occurring due to anterior segment dysgenesis during fetal development. Due to other ocular and systemic comorbidities, a team comprising pediatric cornea, glaucoma, and strabismus specialists in addition to a pediatrician and geneticist is necessary for the appropriate management of these children. Since the outcome of pediatric penetrating keratoplasty is variable and has a higher chance of failure when accompanied by additional procedures, such as lensectomy and vitrectomy, minimally invasive alternatives are increasingly being offered to these patients. Of note is the recently reported novel procedure: selective endothelialectomy for PA, which avoids the need for a corneal transplant and results in gradual clearing of the corneal opacity over time. In this overview, we aimed to describe the etiology, classification, pathophysiology, histopathology, clinical features, and management of PA.

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.

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.

Penetrating Keratoplasty in Infants With Peters Anomaly: Visual and Graft Outcomes

PURPOSE

To determine the prevalence of survival of corneal grafts and visual outcomes of primary penetrating keratoplasty (PK) in infants with Peters anomaly (PA) in Beijing, China.

METHODS

Twenty-nine patients (37 eyes) with PA who underwent PK before the age of 1 year were included. Optical correction for all eyes and occlusion therapy of amblyopia for a unilateral opacity were performed 2 weeks after suture removal. All infants underwent assessment of visual acuity after surgery using Teller Acuity Cards. Survival probabilities were estimated using the Kaplan-Meier method and log-rank test. Visual outcomes and prognosis factors were analyzed using the χ2 test.

RESULTS

The mean age of 29 infants undergoing primary PK was 5.7 ± 2.3 months. The mean follow-up duration was 18.0 ± 3.0 months. Twenty-seven (73.0%) of 37 grafts retained full clarity at final follow-up. Visual acuity above ambulatory was achieved in 67.6% (25/37) and >20/260 was achieved in 48.6% (18/37) of cases. Of all surgical indications, vascularized PA I (50.0%, 6/12) and PA II (18.2%, 2/11) showed a lower proportion achieving visual acuity >20/260 than nonvascularized PA I (71.4%, 10/14) (P = 0.030 < 0.05). There was no significant difference in the prevalence of graft survival and vision outcome between infants younger than 6 months and older than >6 months.

CONCLUSIONS

For infants with PA who underwent PK, the prevalence of graft survival and visual acuity were related mainly to the indication. The main risk factors were corneal vascularization and an abnormal lens.

Terminology of Peters' anomaly variants: Summary of histopathological findings in 6 corneas and detailed clinicopathological correlation in 2 cases

Peters’ anomaly accounts for the highest type of Anterior Segment Dysgenesis (ASD). The main features of Peters’ anomaly are: congenital corneal opacity centrally, defect in the posterior stroma and absence of Descemet’s membrane and the endothelium. However, this condition has wide clinical and histopathological variations in appearance, associations and severity. In this case series, we summarize 6 corneas in 5 Saudi cases of Peters’ anomaly (and describe 2 in detail) with unique histopathological findings that are additional to the typical known ones, shedding some light on the nomenclature of these variants according to the reported cases in the English-written literature. This will widen the spectrum of findings known to ophthalmic pathologists and ophthalmologists about this anomaly. This is also of importance in the assessment of the congenital glaucoma cases commonly seen in Saudi Arabia that often happens in association with ASD.

Long-Term Clinical Course in Eyes With Peters Anomaly

PURPOSE

Peters anomaly (PA) is known to be a primary cause of congenital corneal opacity. The aim of this study is to report the long-term clinical course and visual achievement of patients with PA who did not undergo keratoplasty.

METHODS

This retrospective study involved 15 eyes of 9 infants with PA less than 5 months of age at initial presentation at the Kyoto Prefectural University of Medicine who were followed up without keratoplasty for more than 6 years after presentation. In each subject, visual acuity, intraocular pressure (IOP), presence of congenital glaucoma, and change of corneal opacity were retrospectively investigated.

RESULTS

At initial presentation, the mean patient age was 2.3 months (SD: 1.3; range: 0-4 mo), and the mean follow-up period was 7.9 years (SD: 1.8; range: 6.5-11.3 yrs). Of the 9 patients, 6 were affected bilaterally. Thirteen eyes of 7 patients were found to have glaucoma. Over the follow-up period, corneal opacity gradually decreased in 4 eyes, 1 eye each of 2 unilateral patients without glaucoma and both eyes of 1 bilaterally affected patient with good IOP control during the follow-up period. Visual acuity in the unilateral case with intensive amblyopia treatment gradually increased along with decreasing corneal opacity.

CONCLUSIONS

The findings of this study show that a natural decrease of corneal opacity can occur in eyes with PA. In cases of unilateral PA without IOP elevation and no enlargement of the corneal diameter, strict amblyopia treatment is vital to obtain a favorable visual prognosis.

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.

Long-term clinical course and visual outcome associated with Peters' anomaly

PURPOSE

To investigate the long-term clinical course and visual outcomes of Peters' anomaly cases treated with various treatment modalities.

PATIENTS AND METHODS

All patients with Peters' anomaly treated at Seoul National University Children's Hospital from 1985 to 2005 were reviewed retrospectively. Patients who were followed for more than 5 years after the first visit were enrolled for analysis of the visual outcome. Final visual outcomes were presented with respect to disease severity and treatment modalities. Disease severity was determined according to the corneal status and accompanied eye anomalies in mild or severe form. Treatment plans were classified into the following groups: (1) a medical treatment group; (2) a surgical treatment group; and (3) a no-treatment group.

RESULTS

A total of 106 eyes in 76 patients were diagnosed as Peters' anomaly, and 90 eyes in 65 patients were analysed regarding the visual outcome. Overall, 60 eyes (67%) had severe disease, and 30 eyes (33%) had mild disease. Twenty-six eyes (29%) received medical treatment, 44 eyes (49%) received surgical treatment, and 20 eyes (22%) received no treatment. The mean final visual acuity was 1.415 logMAR, 2.344 logMAR, and 2.282 logMAR, respectively. The visual outcomes of the eyes with mild disease in each group were significantly better than the eyes with severe disease.

CONCLUSIONS

The long-term visual outcomes of Peters' anomaly differed according to the disease severity in each treatment group. Therefore, before making treatment plans for Peters' anomaly, it is important to investigate the corneal status and accompanying eye disease to determine disease severity.

Peters anomaly with post axial polydactyly, bilateral camptodactyly and club foot in a Kenyan neonate: a case report

Introduction

A case of bilateral Peters anomaly with bilateral post axial polydactyly, bilateral camptodactyly, and club foot was examined in a neonatal Kenyan baby girl of African descent who had been delivered in the hospital and admitted to the newborn unit. She died aged five days. There are no cases of Peters anomaly recorded in Africa according to a literature search. In addition, available data point to the majority of the principal associations in Peters anomaly to be genitourinary anomalies, making this case a rare one in its isolated collection of musculoskeletal associations.

Case presentation

A Kenyan baby girl of African descent who was born through a caesarean section presented in the new born unit of our hospital with bilateral corneal opacities, bilateral polydactyly, camptodactyly and club foot.

Conclusion

This is a rare case of Peters anomaly and its association with multiple musculoskeletal abnormalities makes it special.