Moxifloxacin as postoperative prophylaxis for Enterococcus faecalis-induced endophthalmitis after cataract surgery in aphakic rabbits.

PURPOSE: The development of endophthalmitis after cataract surgery often results in significant vision loss. Inhibition of bacterial proliferation in the anterior chamber using antibiotic eye drops is important to prevent endophthalmitis after cataract surgery. We aimed to determine the sensitivity of fluoroquinolones against Enterococcus faecalis ocular isolates and the efficacy of fluoroquinolones to prevent E. faecalis-induced endophthalmitis in aphakic rabbits.

METHODS

The minimum inhibitory concentrations (MICs) of moxifloxacin (MFLX) and levofloxacin (LVFX) used in ophthalmic solutions for 13 E. faecalis isolates obtained from the conjunctival sac or endophthalmitis cases were determined. Eye drops containing MFLX (0.5%), LVFX (0.5%), or saline were administered to aphakic rabbits with endophthalmitis induced by E. faecalis. The eye drops were administered immediately after lensectomy and at 3 and 6 h after cataract surgery (early instillation group) or immediately after lensectomy and at 12 and 15 h after cataract surgery (delayed instillation group). Bacterial growth, electroretinography (ERG), and slit-lamp examination (SLE) were determined throughout the course of infection.

RESULTS

In vitro susceptibility testing revealed that the MICs of MFLX for E. faecalis isolates were lower than those of LVFX. In the early ocular instillation groups, MFLX significantly improved SLE scores, ERG, and viable bacterial counts compared with LVFX and saline (all, P<0.05). There were no significant differences in any parameter between MFLX and saline in the delayed ocular instillation groups.

CONCLUSIONS

Early ocular instillation of MFLX delays retinal damage compared with LVFX when used to treat E. faecalis-induced endophthalmitis after cataract surgery.