[Our further experiences with pathogenesis of pterigia].

Description of three pterygia in a patient, two of them on temporal side. In neighbourhood of the latters large prominent concrements were present in Meibaumian glands which were rubbing conjunctiva and cornea at each eye movement. They were thought to be the cause of these pterygia. On further examinations of pterygia and their surroundings it was found that besides hairs on caruncle and eyelashes in inner canthus also other pathological changes on eyelids may be the cause. Basing on findings in further 253 pterygia it may be accepted that pterygia occur after permanent microtrauma of conjunctiva and cornea. Those microtrauma may be due to pathological hairs on caruncle or in inner canthus and rarely due to concretion of Meibaumian glands, granulomas, Meibaumian cysts, lacrymal points, cysts and warts. In this way all the doubts about origin of pterygia may be explained. Knowledge of the causal factors may help prophylaxis and therapy of pterygium.