2020–2021 BCSC Basic and Clinical Science Course™
11 Lens and Cataract
Chapter 4: Embryology and Developmental Defects
Congenital Anomalies and Abnormalities
Peters anomaly is part of a spectrum of disorders known as anterior segment dysgenesis syndrome, also referred to as neurocristopathy or mesodermal dysgenesis. (See also BCSC Section 6, Pediatric Ophthalmology and Strabismus.) Peters anomaly is characterized by a central or paracentral corneal opacity (leukoma) associated with thinning or absence of adjacent endothelium and Descemet membrane. In Peters anomaly type 1, iris strands adherent to the cornea are often present. In Peters anomaly type 2, the lens is adherent to the posterior cornea. In normal ocular development, the lens vesicle separates from the surface ectoderm (the future corneal epithelium) at approximately 33 days of gestation. Peters anomaly is typically linked with the absence of this separation. It is often associated with mutations in or deletion of 1 allele of the genes normally involved in anterior segment development, including the transcription factors PAX6, PITX2, and FOXC1. Patients with Peters anomaly type 2 may also display the following lens anomalies:
Figure 4-7 Epicapsular star.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.