Developmental ocular abnormalities in rats with X-ray--induced cataract mutation.

Prenatal and early postnatal devpelopment of eyes of Wistar rats with X-ray-induced cataract mutation was assessed histologically, to determine the events leading to cataract formation. A significant phenomenon appeared to be retinal folding, which occurred regularly at 14 to 15 days of gestation and might have pushed the lens against the cornea. A corneal reaction with the lens was indicated by corneal adhesions to the lens, seen frequently during and shortly after the period of retinal folding, and could have stimulated the epithelial hyperplasia that leads invariably to anterior polar cataract in these animals. Changes in the lens fiber cells, which could have been generated by the epithelial hyperplasia, included the sporadic detachment of newly developing fibers from the lens epithelium and the eventual swelling of the anterior ends of fibers still attached to the epithelium. The detached fibers became fusiform and developed postnatally into posterior, suture-associated vacuoles. Anterior uveitis was noted postnatally in some eyes and probably contributed to the subsequent development of the cataract. The results are discussed in the light of congenital anterior polar cataract formation reported in humans and other animals.