OBJECTIVES: To compare the 1) visual recovery, 2) pain and 3) visual outcomes of patients who underwent epithelial laser in situ keratomileusis (epi-LASIK) Flap- ON versus Flap OFF.

METHODS: Prospective, comparative, subject-masked clinical study of 4 eyes of 24 patients with myopia of up to 9.00 diopters who underwent wavefront-guided epi-LASIK using the Bausch and Lomb Epi-separator. After randomization, the epithelium was removed in one eye (flap off) and repositioned in the other eye (flap on). Questionnaires were used to evaluate the postoperative pain and visual recovery in each eye during the first postoperative week. Visual results were analyzed at each postoperative visit.

RESULTS: Mean pain scores were lower with better vision perceived in the flap-off group during the first postoperative week. Seventy-nine percent in the flap-off group and 21% in the flap-on group saw 20/20 or better uncorrected visual acuity (UCVA). At 3 months, 79% of the flap-off group and 83% in the flap-on group had 20/20 UCVA. BCVA was 20/20 in 100% of the flap off group and 96% in the flap on group. Spherical equivalents were within +/-0.50 in 83% of the flap off and 100% in the flap on groups. Contrast sensitivity tests (day conditions with and without glare, and night without glare) were comparable between groups with night glare conditions having better scores in the flap-on group (P=2.97).

CONCLUSION: Eyes that underwent flap off epi LASIK had less pain and faster visual recovery compared to those where the flaps were retained. Visual results at 3 months showed that the UCVA, BCVA, and contrast sensitivity were comparable between the two groups. Key words: surface ablation, epi-LASIK, wavefront-guided LASIK, flap-on, flap-off