A case of Mooren's ulcer associated with a pterygium.

Mooren's ulcer is a clinical entity exhibiting characteristic peripheral circuniferential corneal ulceration. The pathogenesis of Mooren's ulcer is related to conjunctival invasion, and often a pseudopterygium is observedin the subsiding stage of Mooren's ulcer. It is very rare, however, for Mooren's ulcer to occur in the area of a true pterygium. To the best of our knowledge, there is only one report, published in 1976, 1 on this rare complication. We herein report a case of Mooren's ulcer that occurred in the same area as a preexisting pterygium and the results of an immunohistochemical study on excised tissues to elucidate the pathogenesis of this complication.