Dry eye after photorefractive keratectomy (PRK) and transepithelial photorefractive keratectomy (T-PRK): a comparative clinical study.

PURPOSE

To compare dry eye disease (DED) following PRK and T-PRK surgeries using a combined approach of subjective and objective measures, focusing on clinically meaningful outcomes and adjusted statistical modeling.

METHODS

In this prospective observational study, 89 eyes of patients aged over 20 years were enrolled and grouped into PRK (43 eyes) and T-PRK (46 eyes). The primary outcome was change in ocular surface diseases index (OSDI) score at 6 months. Secondary outcomes included non-invasive tear breakup time (NITBUT) and meibomian gland expressibility. Exploratory parameters such as tear meniscus height (TMH), redness score, strip meniscometry (SM Tube), meibomian gland dropout, and meibum quality were also assessed. Statistical models were adjusted for baseline age differences, and corrections for multiple comparisons were applied.

RESULTS

The mean age of the patients was 34.16 ± 7.23 in the PRK and 28.72 ± 6.26 in the T-PRK group (P < 0.001). The two groups were not significantly different for gender (P = 0.367). After statistical adjustment, only the change in OSDI and NITBUT at 1-month remained significant between groups (adjusted P = 0.038 and P < 0.05, respectively). Effect sizes were small to moderate, and none of the differences exceeded minimal clinically important thresholds. Exploratory analyses revealed no significant between-groups differences. Age was identified as an independent predictor of OSDI change.

CONCLUSION

In short-term follow-up, both procedures induced some degree of DED. However, T-PRK was associated with slightly fewer signs and symptoms of dry eye disease, but the differences were not clinically significant.