Abstract
Purpose: :
To evaluate the amoebicidal efficacy of riboflavin and UV-A on Acanthamoeba Castellani, and to expand the armamentarium of antimicrobial agents for the management of severe Acanthamoeba keratitis.
Methods: :
We tested the in vitro effect of chlorhexidine 0.02% alone (C), the one of the riboflavin 1% and UV-A (365nm) light exposure combination (R + UV-A), and the one of these two associated procedures (C + R + UV-A) on trophozoites and Acanthamoeba cysts cultured. The parameters of the UV-A application were the same as those used for in vivo corneal collagen cross-linking. We performed a cell count of each treatment area by optical microscopy at 1, 4 and 8 days.
Results: :
A decrease in the number of cysts was observed for the three treatments (C, R + UV-A, C + R + UV-A). This reduction was more consistant for the agar plates treated with R + UV-A (p <0, 05 on day 1, p <0.01 on day 4, p <0.01 on day 8) and those treated with C + R + UV-A (p <0.05 on day 1, p <0.001 on day 4, p <0.001 on day 8) compared to those exposed to chlorhexidine alone (C). It has not been shown statistically significant difference between groups R + UV-A and C + R + UV-A. There were no decrease in the number of trophozoites for the three treatments (C, R + UV-A, C + R + UV-A), but encystment of them.
Conclusions: :
Our study shows that the riboflavin and UV-A light exposure combination is effective against Acanthamoeba cysts in vitro. This procedure might be used in the future for the management of Acanthamoeba keratitis but the validity of this treatment should be tested in vivo by further studies.
Keywords: Acanthamoeba • antibiotics/antifungals/antiparasitics • keratitis