[Correlation between corneal sensitivity and nerve regeneration following excimer laser ablation].

To compare the recovery of corneal sensitivity and corneal regeneration following excimer laser and manual epithelial debridement, the corneal epithelium of the right eye of New Zealand white rabbits (n = 21) was manually debrided and the left eye was ablated with the excimer laser (47 microns depth, 5 Hz, and 160 mJ/cm2). We observed the wound healing rate and corneal sensitivity. The relative density of innervation on the intraepithelial layer was measured using gold chloride staining or right microscopic examination for 30 weeks. In the laser-ablated cornea sensitivity rapidly increased to a normal level by day 5, and then it continued to increase gradually and reached a maximum at day 42. Thereafter it remained elevated to 126 days and returned to normal at 210 days. There were significant differences in the recovery of sensitivity following excimer ablation and manual epithelial removal. The relative density of innervation on the intraepithelial layer after excimer ablation was significantly higher than manual debridement at day 35. We observed a correlation between increased sensitivity levels and increased nerve density. This result suggests that for photorefractive keratectomy or phototherapeutic keratectomy, manual debridement of the corneal epithelium should be performed before stromal excimer ablation.