Peters anomaly represents the severe end of the spectrum of anterior segment dysgenesis syndromes, in which neural crest cells do not properly migrate or differentiate during embryologic development. This disrupts anterior segment development and, in severe cases, prevents cleavage of the lens from the corneal endothelium. This condition is typically bilateral and sporadic, but autosomal dominant and recessive modes of inheritance have been reported. Studies suggest that mutations in genes, including paired box protein 6 (PAX6), paired-like homeodomain transcription factor 2 (PITX2), and forkhead box C1 (FOXC1), cause anterior segment dysgenesis, including the heritable form of Peters anomaly.
In this anomaly, a localized defect of the endothelium and Descemet membrane, known as internal ulcer of von Hippel, appears centrally or paracentrally. At the edges of the defect, iris strands typically adhere to the posterior corneal surface. In the most severe form of Peters anomaly, the lens also adheres to the posterior corneal surface. The anterior chamber angle may be malformed, predisposing to congenital glaucoma. Associated findings can include sclerocornea, which is characterized by peripheral corneal stromal opacification and vascularization, and cornea plana, in which the curvature of the cornea is flattened (Fig 6-2). In vivo confocal microscopy or anterior segment optical coherence tomography (AS-OCT) can be helpful in distinguishing the different forms of anterior segment dysgenesis. See Chapter 7 in this volume for additional discussion of this entity. See also BCSC Section 8, External Disease and Cornea, and Section 6, Pediatric Ophthalmology and Strabismus.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.