Peters Anomaly

Peters anomaly is a rare congenital disorder of the anterior segment of the eye. It is named after Dr. Alfred Peters, a German ophthalmologist. It is characterized by central corneal opacity of variable size with a corresponding defect in the posterior stroma, Descemet membrane, and endothelium. The peripheral cornea is relatively clear, but a variable degree of haze may be associated with central opacity. In the Peters anomaly, the iridocorneal adhesions typically arise from the collarette and get attached to the margin of the corneal opacity.  This iridocorneal adhesion can present as thin filaments, thick bands, or arcuate sheets. In 1974, Townsend et al. classified the Peters anomaly into three types.Type I involves the cornea alone and presents as a central corneal opacity. Type II presents with corneo-lenticular touch and corneal opacity. Type III has central corneal opacity with Rieger mesodermal dysgenesis. Presently Peters anomaly is classified into two types.  Type I has iridocorneal adhesion with corneal opacity. Type I predominantly involves one eye. Corneal opacity density varies from mild to severe with a clear peripheral cornea. Sometimes peripheral corneal edema or scleralization may also be present. Type I has fewer vitreoretinal and systemic abnormalities as compared to type II. It has a good visual prognosis. Type II has corneo-lenticular touch or corneal opacity with lens abnormalities.  Type II most commonly presents bilaterally. In type II, the lens is directly adherent to the posterior corneal opacity. The lens is cataractous in type II, but it is in the center. The systemic association is more in type II patients. The term Peters-Plus syndrome was first proposed by VanSchooneveld et al. in 1984.  If the Peters anomaly presents with systemic manifestations like cleft lip/palate, short stature, abnormal ears, and intellectual disability, it is called a Peters plus syndrome. Krause-Kivlin syndrome is an autosomal recessive disorder, which has features of Peters anomaly, along with facial abnormalities, disproportionate short stature, and underdeveloped skeletal maturation.