Quantitative analysis of wound healing after cylindrical and spherical excimer laser ablations.

Abstract

Superficial corneal ablation using the 193 nm excimer laser for the correction of myopia and astigmatism produces histologic changes in the corneal profile that can be quantitatively analyzed. Using the excimer laser, spherical and cylindrical corneal ablations were performed on rabbit eyes at depths of 2, 4, 6, and 8 diopters. After 12 weeks, the corneas were examined histologically using a dichlorotriazinyl aminofluorescein stain for collagen, and the results were quantified using a digital video image analysis system. Epithelial thickness and thickness of new collagen were positively correlated with the depth of ablation after spherical ablations. With astigmatic ablations, epithelial thickness and new collagen production were correlated with ablation depth in one axis only. These results suggest that during cylindrical corneal ablations with the excimer laser, radially asymmetrical stromal ablations produce quantitatively asymmetrical wound healing.