A randomized masked pilot clinical trial to compare the efficacy of topical 1% voriconazole ophthalmic solution as monotherapy with combination therapy of topical 0.02% polyhexamethylene biguanide and 0.02% chlorhexidine in the treatment of Acanthamoeba keratitis.

To compare the efficacy of topical voriconazole 1% and the combination therapy of 0.02% polyhexamethylene biguanide (PHMB) and 0.02% chlorhexidine for the treatment of Acanthamoeba keratitis (AK). This is a prospective, pilot, double-masked randomized comparative study. Twenty-three eyes of 23 patients with microbiologically (smear and/or growth on culture) confirmed AK were randomized to group BG (PHMB 0.02% and chlorhexidine 0.02%) or group VZ (voriconazole 1%). Primary outcome measure was change in geometric mean (GM) of the corneal ulcer size at final visit. Secondary outcome measures were change in visual acuity. Out of 71 patients with confirmed AK seen during study period, 23 patients were recruited and 18 patients completed minimum 2 weeks of treatment and further analyzed. Ten patients received BG, whereas eight received VZ. Median ulcer size measured as GM of infiltrate decreased from 5.7 mm (IQR, 5.3-6.5 mm) (p = 0.02) to 1 mm (IQR, 0-4.3 mm) in group BG and from 4.5 mm (IQR, 1.8-5.1 mm) (p < 0.05) to 0.7 mm (IQR, 0-1.6 mm) in VZ group. Median visual acuity improved from 1.79 (IQR, 1.48-2.78) to 1.10 (IQR, 0.48-1.79) in BG group (p = 0.02) and from 1.60 (IQR, 1.00-2.78) to 0.80 (IQR, 0.48-1.30) in VZ group (p = 0.18). These outcomes suggest that topical VZ as a monotherapy in AK treatment is effective and comparable to BG combination therapy but needs trials with larger sample size and longer follow-up to provide conclusive evidence.