Peripheral corneal ulcers in the horse.

This report involves a retrospective study of five horses with an unusual form of progressive peripheral corneal ulcers. These ulcers were located at the perilimbal region of the cornea and spread both centripetally to mid periphery and circumferentially. Lipping of the epithelial edge was observed often. The depth ranged from superficial to mid stroma. Patients ranged from two and a half to eight years, both sexes, and were referred after a variety of antibacterial therapy. Histories were similar in that all ulcers were initially located adjacent to the limbus in one or more quadrants. No trauma was known to antedate the corneal disease and the patients were in good general health. Conjunctivectomy was performed in three patients which revealed an abundance of plasma cells and lymphocytes. All five cases were negative for a specific bacterial pathogen. Patients responded to a variety of treatment modalities: topical corticosteroid, surgical debridement, therapeutic soft contact lens (TSCL), and/or conjunctivectomy.