Preventive Effect Against Post-Cataract Endophthalmitis: Drug Delivery Intraocular Lens versus Intracameral Antibiotics 

Purpose: To compare hydrophilic acrylic intraocular lenses (IOLs) as an antibiotic drug-delivery system with intracameral antibiotic administration in terms of the ability to prevent endophthalmitis. Methods: Antibiotic solutions of 0.3% (3 mg/ml) and 0.5% (5 mg/ml) gatifloxacin (GFLX) and 0.5% (5 mg/ml) and 1.5% (15 mg/ml) levofloxacin (LVFX) were prepared. IOLs made of hydrophilic acrylic and silicone were used. Hydrophilic acrylic IOLs were allowed to adsorb the antibiotic solutions. A clinically isolated strain, KOS1, of Enterococcus faecalis was used to induce experimental endophthalmitis in vivo. Antibiotic concentrations were determined with high-performance liquid chromatography (HPLC). Twelve hydrophilic acrylic IOLs with antibiotics were used for the in vitro antibiotic concentration assay. In vivo experiments were conducted with 51 rabbits in total. Antibiotic concentrations in the aqueous humor and effects against bacterial proliferation were evaluated. Results: Concentrations of released antibiotics in vitro were highest on the first day and had decreased by the second day. When a comparison was made between similar initial concentrations, GFLX was released to a significantly higher concentration than LVFX (p < 0.001). In the antibiotic-treated IOL group, GFLX concentrations in the aqueous humor reached a peak at four hours postoperatively and then decreased. The intracameral antibiotic group showed similar tendencies, with a remarkably higher peak concentration. Effects against bacterial proliferation were comparable between the antibiotic-treated IOLs and intracameral antibiotic administration. Conclusions: Preventive effects against endophthalmitis were similar between antibiotic-treated IOL implantation and intracameral antibiotic administration.