The effect of ofloxacin on the human corneal endothelium

Purpose. Possible toxic effects of ofloxacin on human corneal endothelia were assessed by using electron microscopy and in vitro specular perfusion. Methods. Five pairs of corneas [with one cornea of each pair receiving balanced salt solution (Endosol; Allergan, Irvine, CA, U.S.A.) and the other receiving Endosol with 10 mu g/ml of ofloxacin] underwent perfusion for 3 h with corneal pachymetry every 15 min followed by tissue fixation. A mean corneal swelling rate was calculated from a first-order regression line fit for each of the five experiments. The swelling rates between groups was compared by using a paired t test. Scanning and transmission electron micrographs were examined for cellular architecture. Another group of five pairs of corneas was perfused the same way with the only difference being a test dose of 30 mu g/ml. Results. The mean swelling rate for corneas perfused with 10 mu g/ml of ofloxacin of -3.5 mu m/h was not significantly different from that of the Endosol-alone corneas at -3.0 mu m/h (p = 0.71). The mean swelling rate for cornea perfused at 30 mu g/ml of ofloxacin was -4.1 mu m/h, not significantly different from Endosol-alone per fused corneas at -6.5 mu m/h (p = 0.08). NO consistent ultrastructural changes could be attributed to exposure to 10 or 30 mu g/ml of ofloxacin. Conclusion. Human corneal endothelium can be exposed to ofloxacin at a dose of 30 mu g/ml for a period of 3 h without adverse ultrastructural or physiologic side effects.