Primary Congenital Aphakia

Congenital aphakia is a rare anomaly. Despite its rarity, it appears reasonable to subdivide the condition into two groups: (a)primary congenital aphakia, in which no lens "anlage" has developed, and (b)secondary congenital aphakia, in which a lens has developed to some degree, but has been resorbed or extruded through a corneal perforation before or during birth. That primary congenital aphakia can occur when the optic cup has invaginated and partially developed, has been shown by examination of a human embryo at the 13 mm. stage1in which bilateral aphakia was present, and from a number of histologically studied cases2-6in which primary aphakia could be demonstrated. All these eyes showed severe congenital deformities. Embryology The first sign of lens development is a thickening of the surface ectoderm in the area of contact between the ectoderm and the primary optic vesicle. The ectodermal cells (lens placode) acquire