Abstract
Purpose :
Filamentous fungal keratitis is a challenging disease with poor prognosis. In this randomized clinical trial we compare the efficacy of two commonly used topical antifungal medications, natamycin and amphotericin as well as the effect of adjuvant corneal cross-linking (CXL).
Methods :
In this prospective, 2 x 2 factorial design, randomized, outcome-masked clinical trial, study participants presenting with smear positive filamentous fungal ulcers and visual acuity worse than 20/70 were enrolled at Aravind Eye Hospital in Madurai India. Using an adaptive randomization allocation study participants were assigned to 1 of 4 possible treatment arms: 1) natamycin only; 2) natamycin + CXL; 3) amphotericin only; 4) amphotericin + CXL in a 2 x 2 factorial design trial. The primary outcome was culture taken 24 hours after initiating treatment, secondary outcomes included visual acuity, scar size and complication rates including perforation and rate of therapeutic penetrating keratoplasty.
Results :
111 patients were enrolled between January 2016 and March 2018. Table 1 outlines the baseline characteristics which were similar across the 4 treatment groups. There were small differences in culture status (culture positivity rate: natamycin only, 68%; natamycin + CXL, 81%; amphotericin only, 90%; amphotericin + CXL, 78%) and visual acuity (median [IQR], in logMAR: natamycin only, 1.05 [0.62, 1.12]; natamycin + CXL, 1.10 [0.60, 1.70]; amphotericin only, 1.05 [0.62, 1.70]; amphotericin + CXL, 1.22 [0.91, 1.70]). Culture positive ulcers were mostly Fusarium species (52%), Aspergillus (16%), and Curvularias (8%).
Amphotericin had similar efficacy compared with Natamycin with regard to repeat culture positivity, visual acuity, scar size and complication rates (Figure 1). We found no benefit of CXL on 24 hour repeat culture result. Those randomized to CXL had decreased visual acuity at 3 months compared with medical therapy (regression model of 3-month visual acuity by treatment arm, accounting for baseline visual acuity and comparing each arm to natamycin only: natamycin + CXL, coef. 0.42 [p = 0.03]; amphotericin only, coef. 0.10 [p = 0.59]; amphotericin + CXL, coef. 0.25 [p = 0.19]).
Conclusions :
Amphotericin has similar efficacy compared to Natamycin for the treatment of filamentous fungal keratitis. There is no benefit to adjuvant CXL for the treatment of moderate fungal keratitis.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.