Purpose: To evaluate the sterility of topical glaucoma medications among chronic glaucoma medication users in the community.
Setting: Glaucoma service, Sanz Medical Center, Laniado Hospital, Netanya. Research mode: Cross-sectional laboratory and clinical study.
Patients and methods: Chronic glaucoma patients were asked to submit their topical glaucoma preparations to the microbiology laboratory at Laniado hospital. Samples taken from the interior of the bottle and the tip were cultured using MacConkey agar, blood agar, and chocolate agar plates.
Results: Sixty-two bottles of topical glaucoma medications used by 27 patients were tested. Bacterial growth was detected in eight (12.9%) preparations, three of which revealed Pseudomonas aeruginosa, three Staphylococcus epidermidis, one Streptococcus viridans, and one Klebsiella. During the study, acute conjunctivitis was found in one patient, possibly due to the use of infected drops. In another case, two identical medications, which had been used simultaneously for more than 6 weeks by the same patient, were found to be infected.
Conclusions: Glaucoma topical preparations are generally found safe in terms of sterility, though bacterial growth may be found in a small percentage. In most cases, the cause of the loss of sterility could not be determined. However, in two preparations, contamination was related to the noncompliance of the patient who continued using the same preparation longer than instructed. It is imperative to increase the awareness of glaucoma patients to the fact that improper use can lead to eye-drop contamination.