[Use conditions of boric acid solution in the eye: handling and occurrence of contamination]

To evaluate use conditions and detect contamination in bottles of boric acid solution.

A convenience sample of 42 recruited patients using boric acid solution came to the Ophthalmology Emergency Room of the São Paulo Hospital from February to March of 2003. Cultures were taken from material of the conjunctival sac, inner surface of bottle edge, inner part of cap and from 1 ml of boric acid solution of each bottle.

Of the 42 boric acid solution bottles, 17 (40.5%) showed contamination: 1 (2.4%) in the solution, 17 (40.5%) in the inner cap and 6 (14.3%) in the inner part of the bottle edge. Of the 17 contaminated bottles, 10 (58.8%) were handled inappropriately and 13 (76.5%) of the bottles were not discharged after first use. The most common microorganisms found in the caps and edges of the bottles were Staphylococcus sp (69.6%), followed by Gram-positive bacillus (26.1%). Sixteen bottles (38.1%) had been opened more than a month ago and 5 (31.3%) of those showed contamination. The boric acid solution bottle directions shown on the labels were incomplete and not clear. The use of boric acid solution was on recommendation of their own, friends or relatives in 26 (61.9%) cases; pharmacists in 8 (19.0%) cases, ophthalmologists in 5 (11.9%) cases and general practitioners in 3 (7.1%) cases.

In most cases, the topic use of boric acid solution was recommended by non-physicians. The bottles, in general, were handled inappropriately, and hence presented a much higher level of contamination that did the boric acid solution inside. The lower level of contamination in the solution is possibly associated with the anti-septic characteristics of the boric acid solution.