Abstract
Purpose :
To investigate the efficacy of antimicrobial blue light (aBL) therapy for Candida albicans induced keratitis in an ex vivo model.
Methods :
Blue light (405nm) was delivered onto a bioluminescent strain of C. albicans (CEC749) cultured in vitro to investigate blue light's antimicrobial ability. An ex vivo rabbit model of infectious keratitis was established using this strain. Quantitation of fungal luminescence was correlated to colony-forming units (CFU). Blue light was delivered at 24h after fungal inoculation and the luminescence of infected corneas was detected. The efficacy of aBL therapy for infectious keratitis was then evaluated.
Results :
Blue light was delivered using a mounted light emitting diode (LED). C. albicans was cultured in YPD broth overnight. 3.59-log10 CFU of fungi were inactivated on average when an exposure of 216 J/cm2 blue light had been delivered in vitro. C. albicans induced keratitis was fully developed in rabbit fresh corneas at 24h after inoculation. Fungal luminescence in the infected corneas was correlated linearly to CFU. Fungal burden in the infected corneas was significantly reduced (1.44-log) after an exposure of 288 J/cm2 blue light.
Conclusions :
Antimicrobial blue light therapy can inactivate C. albicans and is a potential treatment for C. albicans-induced keratitis. Further in vivo studies are needed to evaluate corneal and retinal safety when using aBL therapy.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.