Contamination of dropper bottles with tear fluid in an ophthalmic outpatient clinic.

Contamination of dropper bottles with tear fluid in an ophthalmic outpatient clinic The isolation of the human immunodeficiency virus (HIV) from the tears of a patient with the acquired immune deficiency syndrome (AIDS)' has aroused concern about the risks of transmission of the virus during various ophthalmic procedures.2 Current recommendations permit the use of multiple application dropper bottles in ophthalmic outpatient departments, though opened bottles shotild be discarded at the end of each day.3 We performed a simple study to discover whether such bottles can become contaminated with tear fluid during normal use. Methods and results The study took place during a single ophthalmic outpatient clinic. Oxybupro-caine (Benoxinate) was supplied in glass mnultiple application dropper bottles incorporating a dropper in the screw cap. One bottle was provided for each of eight slit lamps. For tonometry we asked that a drop of oxybuprocaine should be instilled into the tear sac after 1% fluorescein, thus reversing the usual order of application. To eliminate bias and otherwise maintain normal practice we did not explain the purpose of the study to the medical staff until afterwards. At the end of the clinic the eight bottles were collected and examined for contamination with fluorescein by using a Perkin Elmer 3000 fluorescence spectrometer set for an excitation frequency of 440 nm and an emission frequency of 510 nm. The instrument was calibrated by using serial dilutions of 1% fluorescein. The volume of drops remaining in each bottle was also measured as a rough guide to the number of times each bottle had been used. The table shows that six of the eight bottles were contaminated with fluorescein. The bottles that were used more frequently tended to have heavier contamination.