Voriconazole, natamycin appear similarly effective for fungal keratitis

This exploratory double-masked study compared treatment outcomes between topical natamycin and topical voriconazole for fungal keratitis. Overall, the authors did not find voriconazole to be superior to natamycin in terms of clinical outcomes or adverse events but a subgroup analysis found a trend toward improved outcomes with voriconazole in patients with moderate visual acuity. The also note a trend toward worse outcomes in patients undergoing repeated epithelial scraping.

Subjects were 120 patients seen at Aravind Eye Hospital in India. They all underwent corneal scraping, the hospital's standard of care for corneal ulcers. They were randomized to treatment with topical natamycin or topical voriconazole, with or without repeated corneal scraping. The medications were applied topically to the cornea every hour while awake for one week, and then every two hours while awake until three weeks after enrollment. Patients in the repeated scraping arm had their epithelium scraped by an ophthalmologist so that the defect was at least as large as the underlying infiltrate at one and two weeks following enrollment.

The authors found no significant differences in visual acuity, scar size and perforations between natamycin-treated and voriconazole-treated patients. They did find a nearly statistically significant two-line benefit in three-month visual acuity with voriconazole in the subgroup of patients with baseline visual acuity of 20/40 to 20/400 (P = 0.07). However, this was an exploratory outcome. The authors note that it will be important for this finding to be reproduced in a confirmatory therapeutic trial of patients who start with visual acuity in this range. Scraping was associated with worse BSCVA at three months after adjusting for the drug used (P = 0.06).

The authors conclude that the results do not support scraping as a fungal keratitis treatment beyond its utility in obtaining a microbiologic sample for culture. They recommend a clinical trial to confirm the benefit seen with voriconazole among patients with baseline visual acuity of 20/40 to 20/400.