Comparative morphology of epicorneal conjunctival membranes in rabbits andhuman pterygium

A rarely described ocular lesion in the rabbit is presented following the o bservation of four cases. It is a membrane of conjunctival origin that adva nces progressively, without adhering, towards the center of the cornea. Cli nically the lesion in rabbits looks like pterygium in man, but with several differences: in rabbits, the conjunctival fold is absolutely free and does not penetrate into the superficial corneal layers. It originates from all the limbal circumference in a symetric growth. The cornea itself remains un altered. The fold consists of fibroblasts and collagen. The microscopic fin dings suggest the lesion is possibly of a collagenous dysplasia.