[Preoperative conjunctival bacterial microbiota of antiangiogenic intravitreous injection for age-related macular degeneration compared to cataract surgery preoperative microbiota].

Purpose: To evaluate the conjunctival bacterial microbiota and antibiogram profile in the preoperative of antiangiogenic intravitreous injection for age-related macular degeneration, and compare to the preoperative microbiota of patients submitted to cataract surgery.

Methods: Cross-sectional, observational, case series study. Two groups were organized: group I (macular degeneration) with 26 eyes from 26 patients (12 men/14 women) with mean age of 69.2 +/- 11.5 years; group II (cataract) with 27 eyes from 27 patients (9 men/18 women) with mean age of 67.6 +/- 7.9 years. The groups were similar regarding age (p=0.538) and gender (p=0.787). The lower conjunctival sac was swabbed and the obtained material was immediately put in a tube filled with liquid culture media BHI ("brain heart infusion"). Samples were processed according to standard laboratory techniques and antibiogram was determined for each bacterial colony.

Results: Twenty-six bacterial colonies growth in group I, with 2 eyes showing no growth and 30 colonies growth in group II. Gram positive bacteria were more prevalent in both groups: 23/26 colonies (88.4%) in group I and 29/30 colonies (96.7%) in group II, with a Staphylococcus aureus predominance in both groups, with 16 samples (61.5%) and 17 (56.7%), respectively. Coagulase negative Staphylococcus was the second most common identified bacteria, with 19.2% in group I and 20.0% in group II. No differences between the groups reached statistical significance. No statistically significant difference was noted on the antibiotic sensibility between both groups.

Conclusions: There was no difference in the distribution of bacteria and antibiogram profile of the conjunctival microbiota in the preoperative of intravitreous injection of antiangiogenic for macular degeneration compared to the preoperative of cataract surgery.