Determination of surgical outcomes with a novel formulation of intrastromal natamycin in recalcitrant fungal keratitis: A pilot study

Purpose: To evaluate the outcomes of water-soluble intrastromal natamycin (IS-NTM) as an adjunct therapy for recalcitrant fungal keratitis. Methods: This was a prospective interventional pilot study in the setting of a tertiary eye-care center. Twenty eyes of 20 consecutive patients with microbiologically proven recalcitrant fungal keratitis (ulcer size >2 mm, depth >50%, and not responding to topical NTM for 2 weeks) were recruited. The selected patients were injected with a novel composition of IS-NTM (10 ug/0.1 mL, soluble natamycin) prepared aseptically in the ocular pharmacology department. All the patients continued using topical NTM suspension 5% 4-hourly until the ulcer healed. Repeat injections were undertaken after 72 h depending on the clinical response and all the patients were followed till 6 months. Results: The mean age of the patients was 40.42 +/- 10.09 years. The mean duration of the presentation was 20.8 +/- 5.1 days. The most commonly isolated organisms were Aspergillus sp. (12/20, 60%) and Fusarium sp. (8/20, 40%). No patient had iatrogenic perforation or precipitate formation after IS-NTM injection. The overall cure rate with IS-NTM was 95% (19/20 patients). The number of patients who healed with the 1st, 2nd, and 3rd injection was 13, 5, and 1, respectively. One (5%) had no response to treatment and was subjected to penetrating keratoplasty. The average time taken for the resolution of the epithelial defect, stromal infiltrates, and hypopyon was 34 +/- 5.2 days, 35.3 +/- 6.4 days, and 15 +/- 2.5 days. Healing with deep vascularization and cataract was noted in 6/19 eyes (31%) and 13/19 eyes (68.42%), respectively. Conclusion: Intrastromal injection of a novel formulation of NTM holds a promising role as adjunctive therapy to topical NTM in the management of recalcitrant filamentous fungal keratitis. The preliminary results are encouraging and further studies are required to validate the results.

Automated summary

This study evaluated the outcomes of water-soluble intrastromal natamycin as an adjunct therapy for recalcitrant fungal keratitis. With IS-NTM injection, no serious adverse reactions were observed, and the overall cure rate was 95%, with an average resolution time of 6 weeks.