[Effect of tonometry and nasolacrimal duct irrigation on bacterial flora of the conjunctiva].

This study was undertaken to assess the influence of preoperative ophthalmological examinations on the microbial flora of the conjunctiva. For this purpose, 112 patients awaiting ocular surgery were included in the study. Conjunctival swabs for microbiological investigation were taken by nurses on the day of admission. In addition, specimens were taken before an ophthalmological examination, after applanation and impression tonometry, after irrigation of the lacrimal duct and 2 h after the end of all examinations. A last swab was taken preoperatively. Comparison of the microbiological results of the first two specimens only showed an agreement in 53% of the cases. The increase after tonometry and irrigation of the lacrimal duct in the number of swabs that were positive was not permanent. Swabs that were primarily germ-free and those that were mostly contaminated also showed strong bacterial fluctuation. Based on the present results, there is no strong evidence that the microorganisms found at the preoperative examinations correlate with a higher risk of postoperative infection. Disinfection of the conjunctival sac and the application of antibiotic drops are necessary on the day before the operation and immediately before it.