Corneal Ring

An annular surface ulcer of the corneal limbus, which corresponds to coalesced ulcers, in a background of marginal keratitis
Etiology Infections—e.g., dysentery, brucellosis, dengue, gonorrhea, hookworms, influenza, TB; connective tissue disease—e.g., SLE—periarteritis nodosa, rheumatoid arthritis, scleroderma, Sjögren syndrome; others—e.g., gold intoxication, ischemia, lethal midline granuloma, leukemia, porphyria, ulcerative colitis, Wegener’s granulomatosis