Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

Definition

A form of anterior segment dysgenesis, a group of defects affecting anterior structures of the eye including cornea, iris, lens, trabecular meshwork, and Schlemm canal. Anterior segment dysgeneses result from abnormal migration or differentiation of the neural crest derived mesenchymal cells that give rise to components of the anterior chamber during eye development. Different anterior segment anomalies may exist alone or in combination, including iris hypoplasia, enlarged or reduced corneal diameter, corneal vascularization and opacity, posterior embryotoxon, corectopia, polycoria, abnormal iridocorneal angle, ectopia lentis, and anterior synechiae between the iris and posterior corneal surface. Clinical conditions falling within the phenotypic spectrum of anterior segment dysgeneses include aniridia, Axenfeld anomaly, Reiger anomaly/syndrome, Peters anomaly, and iridogoniodysgenesis. Some ASGD2 patients show congenital primary aphakia, a defect caused by eye development arrest around the 4th-5th week of gestation. This prevents the formation of any lens structure and leads to severe secondary ocular anomalies, including a complete aplasia of the anterior segment of the eye. In contrast, in secondary aphakic eyes, lens induction has occurred, and the lens vesicle has developed to some degree but finally has progressively resorbed perinatally, leading, therefore, to less severe ocular defects. ASGD2 inheritance is autosomal recessive.

Acronym

ASGD2

Synonyms

Aphakia, congenital primary
Congenital primary aphakia
CPA
CPAK