A 32-year-old male is seen at your office and is in a fair amount of pain. He can barely open his right eye and reports that the pain began this morning when he first opened his eyes. His medical history is unremarkable, and he does not wear contact lenses. His ocular history is remarkable for a mild corneal abrasion of the right eye from a tree branch that occurred over a month ago but had since healed. Biomicroscopy (after instillation of a topical anesthetic) reveals an epithelial defect 1.5 mm wide and 1.0 mm long that stains with sodium fluorescein. There is no anterior chamber reaction and no visible discharge. What is the MOST appropriate diagnosis?
A. Corneal abrasion
B. Corneal ulcer (microbial keratitis)
C. Recurrent corneal erosion
D. Epithelial basement membrane dystrophy