2020–2021 BCSC Basic and Clinical Science Course™
4 Ophthalmic Pathology and Intraocular Tumors
Part I: Ophthalmic Pathology
Chapter 9: Lens
Developmental Anomalies
Early recognition of developmental anomalies of the lens is important to prevent the development of amblyopia. See BCSC Section 6, Pediatric Ophthalmology and Strabismus, and Section 11, Lens and Cataract, for discussion of lens coloboma, ectopia lentis, and congenital cataract, as well as for additional information on the topics discussed in the following sections.
Congenital Aphakia
Congenital aphakia, a rare anomaly, can be divided into 2 forms: primary and secondary. In primary aphakia, the lens is absent histologically. The anomaly results from failed lens induction from the surface ectoderm during embryogenesis and is caused by homozygous mutations in the FOXE3 gene. Primary aphakia is associated with severe ocular and systemic developmental anomalies. The histologic findings of secondary aphakia depend on the underlying etiology. In this form of congenital aphakia, the lens is developed but is resorbed or extruded before or during birth. Secondary aphakia is often associated with congenital infections such as rubella.
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.