Objective: To compare the antimicrobial effects of locally available multipurpose contact lens solutions (MPS) on the growth of standard strains of contact lens-related ocular pathogens and to establish the recommended duration of exposure to these solutions to achieve maximal antimicrobial efficacy. Methods: This study, a single-blind controlled experiment, evaluated five locally available MPS in terms of their antimicrobial efficacy towards common contact lens-related ocular pathogens, such as P. aeroginosa, S. aureus, E. coli, F. solani, and C. albicans, using the stand alone criteria. Microbial viability counts were obtained at serial durations: after 1 hour, 3 hours, 6 hours, and 12 hours of exposure. Results: MPS containing polyquaternium-1 and myristamidopropyl dimethylamine (MAPD) and polyhexamide reduced the bacterial concentrations by 3 log and fungal concentrations by 1 log, enabling them to fulfill the stand alone criteria for disinfecting solutions as mandated by ISO/CD 14729. This antimicrobial efficacy was most evident at 6 hours of exposure to the challenge organisms. MPS containing polyquaternium-1 and MAPD also have the broadest spectrum of effectivity against gram-negative and gram-positive bacteria, and C. albicans. All MPS tested have poor microbial activity against F. solani. Conclusion Multipurpose contact lens solutions demonstrated variability in their antimicrobial activity. MPS with broad spectrum efficacy and effectivity, such as those containing polyquaternum and MAPD, are preferred to prevent contact lens-related ocular infections.
Contact Lenses

Objective: To determine the in-vitro activity of voriconazole and compare it with amphotericin B, fluconazole, itraconazole, ketoconazole, and caspofungin against local yeast and mold clinical isolates Candida albicans, Candida sp., Aspergillus terreus, Aspergillus niger, and Fusarium cylindrocarpone. Methods: Review of the Institute of Ophthalmology microbiology records were done and was the basis for the local isolates included in the study. Mean inhibitory concentration (MIC) was determined using YeastOne Sensititre Microtitre Colorimery method (TREK Diagnostic Systems, England). Two-way ANOVA, Duncan, and Pearson chi-squared tests were used to analyze the data. Results: All isolates tested were sensitive to voriconazole. Eighty percent (80%) of the isolates were sensitive to amphotericin B and 25% showed resistance to itraconazole. Yeast pathogens were all sensitive to amphotericin B and voriconazole. More than 50% of the yeast pathogens were resistant to ketoconazole. Molds or filamentous fungi showed higher susceptibility to voriconazole than amphotericin B and the other antifungals. Conclusion Voriconazole exhibited good in-vitro activity against the isolates tested. It has the same efficacy on yeast pathogens (Candida albicans and Candida sp.) when compared with amphotericin B. It has superior efficacy on filamentous fungi (Aspergillus and Fusarium). There is a role for voriconazole in the treatment of ocular infections, especially in the setting of poor antifungal drug availability.
Voriconazole ; Amphotericin B ; Candida ; Fusarium ; Aspergillus