Effect of mitomycin-C on the corneal endothelium during excimer laser surface ablation

To study the effects of mitomycin-C (MMC) on the corneal endothelium after surface ablation.

This prospective observer-masked study comprised 40 consecutive patients (80 eyes) scheduled to have laser-assisted subepithelial keratectomy (LASEK) to correct myopia. The patients were divided into 2 groups. Group 1 included 32 eyes in which the ablation depth was 50 mum or less and that received no MMC. Group 2 included 48 eyes in which the ablation depth exceeded 50 mum and were treated with intraoperative MMC 0.02% for 30 seconds over the ablated zone. Preoperatively and 3 months postoperatively, 3 photographs of the central cornea of each eye were obtained using specular microscopy. A masked observer evaluated the endothelial cell density and compared the results between groups and the preoperative versus the postoperative results within the same group.

The mean patient age was 31.5 years +/- 4.6 (SD) in Group 1 and 33.2 +/- 7.9 years in Group 2 (P = .3). Within-group comparison between the preoperative and postoperative endothelial cell density values showed a statistically significant increase in both groups. The mean values in Group 1 were 2462.5 +/- 226.8 cells/mm(2) preoperatively and 2562.5 +/- 258.7 cells/mm(2) postoperatively (P = .0001). The means in Group 2 were 2466.6 +/- 294.1 cells/mm(2) and 2525 +/- 312.5 cells/mm(2), respectively (P = .0008). The differences in endothelial cell counts between Group 1 and Group 2 preoperatively and postoperatively were not statistically significant (P = .9 and P =.5, respectively).

A single intraoperative application of MMC 0.02% for 30 seconds after laser surface ablation did not seem to cause a substantial change in corneal endothelial cell density.