Eye drop contamination comes from bottle, not solution

Bottles of infected eye drops are more likely to be contaminated with bacteria at the bottle tip and not within the solution, according to a study presented at this year's American Society of Cataract and Refractive Surgery (ASCRS) meeting.

Gerald W. Zaidman, MD of New York Medical College, US and colleagues tested 47 bottles of glaucoma, anaesthetic, anti-inflammatory, dilating and antibiotic eye drops. The team found that 23% of bottles (n=11) that had previously been opened presented positive bacterial cultures, all of which were species of Staphylococcus.

The team surmised that the infections had been transferred onto the bottle from physical contact with physicians or patients. As these infections were limited to the tip of the bottle, cleaning the tip could prevent bacterial contamination.