Optimal Duration for the Use of 0.5% LevofloxacinEye Drops Before Vitreoretinal Surgery

To investigate various regimens of prophylactic antibiotic therapy for vitreoretinal surgery.

This study compared different prophylactic therapies with 0.5% levofloxacin eye drops.

Two hundred nine patients from 7 hospitals scheduled to undergo vitreoretinal surgery were randomized into 3 groups to receive 0.5% levofloxacin eye drops for 1 day (6 times/d), 2 days (3 times/d), or 3 days (3 times/d) before surgery (groups 1D, 2D, and 3D, respectively). all patients received 3 applications of levofloxacin eye drops at 15-minute intervals beginning 1 hour before surgery and conjunctival sac disinfection with 5.0% povidone-iodine 15 minutes before surgery. conjunctival swabs were cultured before levofloxacin therapy (T0), on the morning of surgery (T1), after povidone-iodine disinfection (T2), immediately after surgery (T3), 1 day postoperatively (T4), and 1 week postoperatively (T5).

The positive bacterial culture rates in groups 1D, 2D, and 3D fell, respectively, from 37.33%, 30.77%, and 31.88% at t0 to 10.67%, 12.31%, and 11.59% at t1 and 1.33%, 0%, and 0% at T2. at each time point (T0-T5), there were no significant differences among the groups in positive bacterial culture rate. the bacterial eradication rates in groups 1D, 2D, and 3D were, respectively, 100%, 94.74%, and 90.00% at T1 (after levofloxacin) and 100% in all groups at T2 (after povidone-iodine).

The efficacy of levofloxacin in preventing postoperative infection was similar in the 3 treatment groups. it is recommended that 0.5% levofloxacin be used for only 1 day before vitreoretinal sur-gery (6 times/d) to minimize the use of prophylactic antibiotics.