Microbiological Evaluation of Bandage Soft Contact Lenses Used in the Management of Persistent Corneal Epithelial Defects

To investigate the rate and agents of contamination in bandage soft contact lenses fitted for the management of persistent corneal epithelial defects and to evaluate potential variables that could influence contamination risk. This prospective comparative case series enrolled 57 consecutive eyes fitted with bandage contact lenses for the treatment of persistent corneal epithelial defects. The lenses were collected at the time of epithelial closure or when it was necessary to exchange contact lenses and were immediately placed in sterile tubes containing an enriched thioglycolate liquid medium. When contamination of the contact lens was detected, the microorganism was cultured in different media and identified based on various tests. All isolates were tested for susceptibility to various antibiotics. Univariate analyses were used to evaluate the influence of different variables on bandage contact lens contamination. Seventeen of the contact lenses (29.8%) were contaminated. The most commonly isolated pathogen was Staphylococcus epidermidis (n=10), followed by Enterobacter cloacae (n=3), Staphylococcus aureus (n=1), Streptococcus viridans (n=1), and Alcaligenes spp. (n=1). One contact lens yielded a mixed infection with Enterobacter cloacae and Candida spp. Infectious keratitis was not observed in any eyes. Correlations between contact lens contamination and investigated variables were statistically non-significant. A significant number of bandage contact lenses used for the management of persistent corneal epithelial defects yielded positive cultures for aerobic bacteria. However, no cases of infectious keratitis were observed. Contamination was independent of different investigated variables, including the duration of contact lens use.