Potential Microbial Contamination of Ophthalmic Solutions Commonly Used in Ophthalmology Outpatient Settings.

Abstract

Purpose : To determine the rate of microbial contamination of three commonly used eye drops following regular clinical use.

Methods : Bacterial cultures from 120 labeled bottles (stored at room temperature in clinics) of Fluorescein Sodium, Proparacaine, and Tropicamide were obtained at days 0, 28, 42, and 56 following regular clinical use by plating 100 μl volume onto chocolate agar and incubating at 37° C for 48 hours.

Results : Rates of bacterial contamination were found to be 1.66, 2.75, 0 and 0% at days 0, 28, 42 and 56, respectively.

Conclusions : Eye drops may be used safely for up to 56 days (potentially longer with additional testing) following regular clinical use without significant risk of microbial contamination, most likely secondary to self-sterilizing property (presence of preservatives) of the solutions.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Figure 1. One hundred twenty bottles of Fluorescein Sodium (n=40), Proparacaine (n=40), and Tropicamide (n=40) placed into service within Truhlsen Eye Institute were cultured, with rates of bacterial contamination found to be 1.67 (n=2), 2.73 (n=3), 0, and 0% at days 0, 28, 42, and 56, respectively. Of the solutions with positive bacterial cultures (n=5), four were contaminated with coagulase negative staphylococci and the remaining one with alpha hemolytic streptococci, both considered to be normal ocular flora.