Trends and Clinical Outcomes of Fungal Keratitis in Canada: A 20-year Retrospective Multicentre Study

center dot PURPOSE: An increase in fungal and particularly filamentous keratitis has been observed in many geographic areas, mostly in contact lens wearers. This study seeks to characterize long-term trends in fungal keratitis in a continental climate area to provide guidance for diagnosis and treatment. center dot DESIGN: Retrospective multicentric case series. center dot METHODS: Cases of microbiology-confirmed fungal keratitis from 2003 to 2022 presenting to tertiary care centers across Canada were included. Charts were reviewed for patient demographics, risk factors, visual acuity, and treatments undertaken. center dot RESULTS: A total of 138 patients were identified: 75 had yeast keratitis while 63 had filamentous keratitis. Patients with yeast keratitis had more ocular surface disease (79% vs 28%) while patients with filamentous keratitis wore more refractive contact lenses (78% vs 19%). Candida species accounted for 96% of all yeast identified, while Aspergillus (32%) and Fusarium (26%) were the most common filamentous fungi species. The mean duration of treatment was 81 +/- 96 days. Patients with yeast keratitis did not have significantly improved visual acuity with medical treatment (1.8 +/- 1 LogMAR to 1.9 +/- 1.5 LogMAR, P = .9980), in contrast to patients with filamentous keratitis (1.4 +/- 1.2 LogMAR to 1.1 +/- 1.3 LogMAR, P = .0093). center dot CONCLUSIONS: Fungal keratitis is increasing in incidence, with contact lenses emerging as one of the leading risk factors. Significant differences in the risk factors and visual outcomes exist between yeast keratitis and fil amentous keratitis which may guide diagnosis and treat- ment. (Am J Ophthalmol 2024;265: 147-155. Crown Copyright (c) 2024 Published by Elsevier Inc. All rights reserved.)