Corneal epithelial wound healing after excimer laser photorefractive and photoastigmatic keratectomy (PRK and PARK).

PURPOSE

This study compared the duration of corneal reepithelialization between photorefractive (PRK) and photoastigmatic (PARK) keratectomy and evaluated the possible correlation of the epithelial healing rate with clinical parameters as well as the refractive outcome.

METHODS

The duration until complete reepithelialization was examined in 33 eyes of 33 patients (14 men), not suffering from any known disease, who underwent PRK or PARK surgery. In all cases, a +0.5 diopters (D) therapeutic contact lens (Acuvue Vistakon) was used postoperatively. Clinical parameters such as age, sex, preoperative spherical equivalent, attempted correction, corneal curvature, and surgical plan were recorded in the patient file. All patients received standard medication and were followed up for 12 months postoperatively. Results were statistically analyzed by using the package SPSS 6.0.

RESULTS

The duration of reepithelialization was significantly correlated to age and was longer in PARK than in PRK cases and in eyes with an average K reading >43.5D. A shorter reepithelialization period correlated to myopic regression, 1 month postoperatively, but the correlation was annulled thereafter.

CONCLUSION

The longer reepithelialization period in older patients and in PARK surgery could be attributed to the age-related decrease in the healing response and to differences in the profile of the ablation area, respectively. Epithelial healing was shorter in eyes with steeper K readings, perhaps because of better contact lens mobility. Understanding the role of factors involved in epithelial healing could allow better postoperative surveillance and treatment.