Therapeutic lamellar keratectomy in the management of experimental keratomycosis.

Keratomycosis, a vision-threatening corneal infection, is a challenge to the ophthalmologist because it is often refractory to medical treatment. Surgical keratectomy may not only debulk the major infectious source but potentiate the intracorneal penetration of the antifungal agents. To evaluate the efficacy of keratectomy in managing the fungal corneal ulcer, three common keratomycosis models, Candida, Fusarium, and Aspergillus keratitis, were established in 46 eyes of 23 rabbits (each group had 14, 16 and 16 eyes respectively). Within each keratitis group, the infected eyes were randomly divided into equally numbered experimental and control subgroups. The eyes of the experimental subgroups underwent therapeutic lamellar keratectomy once the typical fungal corneal infection had developed after inoculation. Following keratectomy, eyes of both the treated and control groups received natamycin eyedrops and were regularly examined biomicroscopically. Our results showed that therapeutic lamellar keratectomy is beneficial in chronic, indolent keratitis, such as Candida and Fusarium keratitis, where it promoted corneal healing and shortened the duration of treatment required. The procedure is a valuable adjunctive measure for antifungal agents in these two types of keratitis. However, acute keratitis of the Aspergillus group did not benefit from keratectomy; in these cases, surgery may actually increase the risk of corneal perforation.