In Vitro Efficacy of Chlorhexidine and a riboflavin/UVA Combination on Fungal Agents of Keratitis

Curr Eye Res. 2020 Jan;45(1):7-11. doi: 10.1080/02713683.2019.1652916. Epub 2019 Aug 14.

Abstract

Purpose: Mycotic keratitis is a global ophthalmological problem because it is difficult to diagnose and treat. The aim of the current study was to evaluate the efficiency of using antifungal agents amphotericin B (AMB), voriconazole (VRC), 0.02% chlorhexidine (CHX), and a combination of riboflavin and UVA treatment against two fungal genera (Aspergillus and Fusarium) responsible for keratitis.Methods: We evaluated antifungal efficiencies of riboflavin/UVA and the antifungal drugs VRC, AMB, and CHX (alone and in combination) against fungal inocula at four concentrations. We recorded colony counts of isolates for Aspergillus terreus, A. flavus, A. fumigatus, Fusarium falciforme, F. proliferatum, and F. solani on Mueller-Hinton agar plates.Results: Fungal suspensions exposed to the following treatment combinations did not allow fungal growth: riboflavin/UVA and VRC, riboflavin/UVA and AMB, riboflavin/UVA and CHX, and CHX alone. We observed a statistically significant reduction (P < .05) in the number of colonies on agar plates when fungal suspensions were treated with riboflavin/UVA, VRC, and AMB only.Conclusions: Riboflavin/UVA treatment in combination with AMB, VRC, and CHX are capable of killing keratitis-inducing fungi (P < .05). The antiseptic CHX exerted a considerable antifungal effect on all strains we examined. Therefore, we recommend CHX as additional therapy against mycotic keratitis, particularly when keratitis is caused by multi-resistant members of Fusarium.

Keywords: Antifungal agents; antiseptic; chlorhexidine; cross-linking; keratomycosis; voriconazole.

MeSH terms

  • Anti-Infective Agents, Local / pharmacology
  • Chlorhexidine / pharmacology*
  • Drug Therapy, Combination
  • Eye Infections, Fungal / microbiology
  • Eye Infections, Fungal / therapy*
  • Fungi / drug effects
  • Fungi / isolation & purification*
  • Fungi / radiation effects
  • Humans
  • Keratitis / microbiology
  • Keratitis / therapy*
  • Microbial Sensitivity Tests
  • Riboflavin / pharmacology*
  • Ultraviolet Rays*
  • Vitamin B Complex / pharmacology

Substances

  • Anti-Infective Agents, Local
  • Vitamin B Complex
  • Chlorhexidine
  • Riboflavin