Comparison of toxicities of moxifloxacin, cefuroxime, and levofloxacin to corneal endothelial cells in vitro

Purpose To evaluate and compare the toxic effects of moxifloxacin, cefuroxime, and levofloxacin on human corneal endothelial cells in vitro and determine the safe intracameral concentrations for them. Setting Tottori University, Tottori, Japan. Design Experimental study. Methods Human corneal endothelial cells in culture were exposed to moxifloxacin, cefuroxime, and levofloxacin at concentrations up to 2000 μg/mL. Evaluation of membrane damage was determined by ethidium homodimer-1 uptake and cell viability, by intrinsic esterase activity. The inhibitory effects of the 3 antibiotics on the constitutive secretion of interleukin-6 (IL-6) by human corneal endothelial cells were determined by enzyme-linked immunosorbent assay. Results The acute effects (6 hour) of the 3 antibiotics on membrane damage and cell death were dose-dependent for moxifloxacin and levofloxacin (≥500 μg/mL). For cefuroxime, membrane damage was not observed at 6 hours and only slight damage was detected at 24 hours at concentrations higher than 500 μg/mL. The half maximum inhibitory concentrations on cell viability of moxifloxacin, levofloxacin, and cefuroxime were 487 μg/mL, 578 μg/mL, and 1600 μg/mL, respectively. The inhibitory effects of the 3 antibiotics on the constitutive secretion of IL-6 were observed at 15.6 μg/mL or higher, indicating the antibiotics can impair the secretion of the protective cytokine even at low concentrations. Conclusions Moxifloxacin at more than 500 μg/mL caused damage to the cell membranes of corneal endothelial cells; even higher concentrations decreased cell viability. Considering the lower minimum inhibitory concentration for inhibiting 90% growth by moxifloxacin, intracameral moxifloxacin at 500 μg/mL or less is recommended for prophylactic use. Financial Disclosure Dr. Inoue is a medical advisor to Alcon Japan Ltd. No author has a financial or proprietary interest in any material or method mentioned.