Evaluation of corneal intrastromal voriconazole injection as an adjuvant approach in recalcitrant fungal keratitis.

Abstract

Background: Fungal keratitis is a sight-threatening condition that accounts for approximately 30-40% of keratitis cases in developing countries. Its management remains challenging despite the availability of various antifungal agents, highlighting the potential role of targeted drug delivery in recalcitrant cases.

Purpose: To evaluate the efficacy of corneal intrastromal voriconazole (ISV) injection in the management of fungal keratitis unresponsive to conventional antifungal therapy.

Methods: This prospective interventional case series included 21 eyes of 21 patients with smear-positive fungal keratitis that failed to respond to at least two weeks of topical antifungal therapy. All patients underwent detailed ophthalmological examination and ulcer assessment using anterior segment optical coherence tomography (AS-OCT). Intrastromal voriconazole (50 µg/0.1 mL) was administered circumferentially around the ulcer. Treatment response was evaluated through serial follow-up, including assessment of ulcer size, infiltrate extent, hypopyon level, presence of satellite lesions, and best-corrected visual acuity (BCVA).

Results: The mean age of the patients was 57.19 ± 6.74 years, with a predominance of males (76.2%). Most patients were from rural areas (76.2%) and had a history of vegetative trauma (71.4%). The mean ulcer size was 4.64 ± 0.95 mm, and the mean infiltrate size was 6.43 ± 1.29 mm. Hypopyon was present in 57.1% of cases, and the mean ulcer depth measured by AS-OCT was 257.14 ± 68.12 μm. Aspergillus was the most isolated organism (52.4%). BCVA improved significantly from 2.71 ± 0.46 LogMAR at baseline to 1.34 ± 0.68 at 3 months (P < 0.001). Complete resolution was achieved in 19 patients (90.5%). Fourteen patients (66.7%) responded to a single injection, while five (23.8%) and two (9.5%) required two and three injections, respectively. Most cases (84.2%) resolved within 2-4 weeks. Two patients (9.5%) showed disease progression and required therapeutic penetrating keratoplasty and were excluded from the final analysis.

Conclusion: Intrastromal voriconazole injection appears to be an effective adjunctive treatment for recalcitrant fungal keratitis, improving clinical outcomes and potentially reducing the need for therapeutic or tectonic keratoplasty.