Aim: To evaluate and compare the clinical outcomes of epi-LASIK performed either on-flap or off-flap with or without 0.02% mitomycin-C (MMC) in terms of corneal haziness, pain scores and satisfaction scores.
Methods: In this nonrandomised comparative retrospective study, the charts of 198 patients (394 eyes) who had undergone an epi-LASIK procedure for myopia (-1.5D to -8.0D spherical equivalent) correction were reviewed. Patients were classified into four groups: Group I: on-flap without MMC, 181 eyes; Group II: on-flap with MMC, 52 eyes; Group III: off-flap without MMC, 93 eyes; Group IV: off-flap with MMC, 68 eyes. We compared the group outcomes on the first day, 1, 3 and 6 months and 1 year after the operation.
Results: The mean uncorrected visual acuity was significantly better in the off-flap groups (III, IV) than the on-flap groups (I, II) on day 1 (P = 0.002). There was no significant difference in the spherical equivalent among all groups at 1 year (P = 0.305). Some degree of haziness was present in 10 eyes (Grade II: 2, Grade I: 8), but the haziness level was not significantly different among groups at 1 year (P = 0.533). Pain scores (0-10) were lower in the off-flap groups (III, IV) (P = 0.010). Satisfaction scores (0-10) were higher in the off-flap groups (III, IV), but the difference was not statistically significant (P = 0.248).
Conclusions: Myopic correction by epi-LASIK surgery with all four methods showed stable visual results in terms of the one-year postoperative clinical outcomes. Haziness levels revealed that treatment with 0.02% MMC was less effective than expected. Overall, the off-flap method offered faster visual recovery and less postoperative pain than the on-flap method.