Ecology of Mooren's ulcer in Nigeria.

Five cases of Mooren's ulcer in young Nigerians seen over a 2-year period, in Lagos, healed after limbal conjunctivectomy. The maximum follow up in 2 cases was 2 years. Previous trauma or corneal foreign bodies as seen in four of our cases seem to suggest the precipitation of Mooren's ulcer by various ocular insults. We believe that collagenolytic activity of the conjunctiva plays a prominent role in the pathogenesis of the ulcer and is supported by this report in which our five cases healed after excision of the limbal conjunctiva. Helminthosis, found in four of our five patients with Mooren's ulcer in an endemic area, such as Nigeria may be an associated finding. The presence of lymphocytes and plasma cells in the histopathology of the excised tissue in one of our cases is suggestive of an autoimmune phenomenon in this disease.