Bacterial contamination of multi-use antibiotic steroid eye ointments and drops

This comprehensive prospective study aimed to investigate the bacterial contamination of antibiotic steroid eye ointments and drops frequently used by eye patients.

In this comprehensive prospective study, a total of 410 multi-use topical eye medications containing 15 different ingredients from 22 pharmaceutical companies used by 185 patients were analyzed. Four groups were formed as follows: group 1: antibiotic ointments (n: 109); group 2: antibiotic drops (n: 103); group 3: steroid ointments (n: 67); and group 4: steroid drops (n: 131). Topical multi-use eye drops and ointments used by patients at home for at least 1 week were randomly collected. The caps and contents were separately bacteriologically examined in a chocolate agar medium.

Our study detected bacterial contamination in 23 containers (5.6%) of the total 410 topical drugs. According to the groups, bacterial contamination was detected in 10 of 67 (14.9%) steroid ointments, 6 of 109 (5.5%) antibiotic ointments, 4 of 131(3.1%) steroid drops, and 3 of 103 (2.9%) antibiotic drops. While the bacterial contamination rate in ointments was 9.1%, this rate was 3% in drops. The difference between them was statistically significant (p = 0.015). According to the post-hoc pairwise comparisons, the difference between steroid drops and steroid ointment (p = 0.0023) was statistically significant. Among all drugs, contamination was detected in 12 of the 93 (12.9%) containers used after keratitis, conjunctivitis, and inflammatory conditions. It was determined that preservatives statistically reduced bacterial growth on the cap. The preservatives did not have a statistically significant effect on the bacterial contamination of the contents compared to the caps. While all contaminations were detected in illiterate and primary school graduates, no contamination was seen in the drugs used by any secondary school or university graduate.

Our study detected contamination in all topical ophthalmic drug groups. Contamination rates were found to be higher in ointments and steroids. Bacterial contamination was also seen in drugs containing preservatives. We should be careful in the use of topical medications. We do not recommend the bilateral use of ointments and drops in infected eyes, such as those with keratitis, or after intraocular surgeries, such as those for cataracts.