Suppurative interstitial ring keratitis due to streptococcus.

Three cases of interstitial ring abscess of the cornea caused by different strains of streptococcus are described. These infections occurred in three different clinical settings: after penetrating trauma at the limbus, after a cataract operation, and in conjunction with keratoconjunctivitis sicca. The acute appearance of a light, interstitial ring not extending to the limbus in the post-traumatized eye should alert the clinician to the possibility that a streptococcus may be responsible. The ring frequently progresses rapidly to a total ring abscess with intraocular extension. The outcome was poor in all three patients.