Open Drops in Ophthalmology Offices: Expiration and Contamination

Abstract

OBJECTIVE: To determine the relationship between eye drop use and contamination rate in ophthalmology offices. DESIGN: Following permission request, open bottles were examined and the nozzle tip and one drop of content was cultured on solid media. OUTCOME MEASURES: Drug category, volume, weight compared to full, clean legible label, expiration date; 2 or more bacterial colonies along the inoculation site. RESULTS: In 18 offices, of 1,485 open bottles (mean 12.2, range 4 to 23 per lane) on average 19.8% (range 0% to 88%) were expired (16.2 of 82.5 bottles per office). The frequency of occurrence (%) and expiration (%E) were 40.3% cycloplegics (19.4%E); 16.4% glaucoma (33.7%E); 10.8% anesthetics (8.8%E); and 4% steroids (8.8%E; or 42.2%E including one outlier). Most likely expired were glaucoma (P < 0.001); small 2-3 ml (P < 0.02), nearly empty (P < 0.05), or dirty (P < 0.001) bottles. Only one (5 ml cyclopentolate, not expired) grew a Micrococcus (0.07%). CONCLUSIONS: Drops in ophthalmology offices may be expired but are not contaminated.