Topical voriconazole effective against Acanthamoeba keratitis

Topical voriconazole (VZ) monotherapy provides relief from Acanthamoeba keratitis (AK) comparable to the combination of polyhexamethylene biguanide (PHMB) and chlorhexidine, a recent study has found.

The prospective, pilot, double-masked, randomized study enrolled 18 eyes from 18 patients who had microbiologically confirmed AK. Participants were assigned to receive 1% VZ (VZ group; n=8) or 0.02% PHMB and 0.02% chlorhexidine (BG group; n=10). The primary outcome was the change in geometric mean (GM) of the corneal ulcer size at the final visit.

At baseline, the median ulcer size, measured as the GM of the longest and widest perpendicular diameters of infiltrate, were 5.7 and 4.5 mm in the BG and VZ groups, respectively. At the final follow-up, infiltrate GM size in the BG group dropped to 1 mm, representing a statistically significant decrease (p=0.02).

Similarly, VZ participants saw a significant reduction in GM, dropping to 0.7 mm by the end of the trial (p<0.05). In terms of percentage change, BG triggered a 95.6-percent decrease in infiltrate size, while VZ led to a 92.1-percent reduction.

Moreover, the median inflammation scores likewise decreased significantly after treatment in both the BG (p=0.03) and VZ (p<0.05) groups; in both cases, scores dropped from 2.0 to 0.5.

In turn, median visual acuity improved, but only significantly so in the BG arm (1.79 to 1.10 logMAR; p=0.02). The improvement in the VZ group was only marginal (1.60 to 0.90 logMAR; p=0.18).

“[A]s a proof of concept, this study provides important information related to efficacy of topical VZ as a monotherapy and additional studies with multicentric trial with larger sample size with lesser limitations will be able to add more evidence related to the utility of VZ,” the researchers said.