• Four patients had idoxuridine-induced conjunctival cicatrization similar to ocular cicatricial pemphigoid develop, but in the treated eye only. Three of the four patients had chronic, recurrent herpes simplex epithelial and stromal keratitis. The fourth patient had Sjögren's syndrome. All received idoxuridine (0.1% drops and/or 0.5% ointment) and topical corticosteroids from one to 3½ years. Substantial morbidity resulted that included visual loss, stromal ulceration, corneal scarring, and keratinization. Conjunctival biopsy specimens showed cicatrization with a mixed inflammatory cell reaction and absence of goblet cells. Results of direct immunofluorescent microscopy of the conjunctiva were either negative or nonspecific for autoantibody. No circulating autoantibody was detected in any of the four patients.