ABSTRACT
PURPOSE: To compare the changes in posterior corneal curvature using scanning slit topography (Orbscan II) and Scheimpflug imaging (Pentacam) before and after Epi-laser in situ keratomileusis (LASIK) for myopia. METHODS: In a prospective observational case-series study, 20 myopic patients having undergone Epi-LASIK were examined serially with two different devices, Orbscan II and Pentacam, preoperatively and one month postoperatively. Posterior central elevation (PCE) and posterior maximal elevation (PME) were compared between the two devices, and the changes in parameters after Epi-LASIK were analyzed using a difference map. RESULTS: All parameters (preoperative and postoperative PCE and preoperative and postoperative PME) that were measured using the Orbscan II were significantly greater compared to those of the Pentacam (for all p < 0.001). PCE and PME were significantly increased one month postoperatively in the Orbscan II measurements (p < 0.05) but were not significantly increased in the Pentacam measurements. Also, DeltaPCE and DeltaPME, in the difference map obtained by each serial scanning, were significantly greater in the Orbscan II measurements than with the Pentacam (p = 0.012, p = 0.016). CONCLUSIONS: The Pentacam measurements displayed significantly reduced values in all parameters related to posterior corneal elevation compared to those of the Orbscan II. The Pentacam showed no significant change in posterior corneal curvature after Epi-LASIK, based on the difference map.
Subject(s)
Adult , Female , Humans , Male , Corneal Topography/methods , Keratomileusis, Laser In Situ/methods , Myopia/surgery , Prospective Studies , Treatment OutcomeABSTRACT
PURPOSE: To compare the results of laser epithelial keratomileusis (LASEK) and epi-laser in situ keratomileusis (Epi-LASIK) for the treatment of moderate to high myopia. METHODS: In this study, 50 patients with a manifest refraction of moderate to high myopia were assigned to two groups: 50 eyes of 25 patients treated with LASEK and 50 eyes of 25 patients treated with epi-LASIK. Uncorrected visual acuity (UCVA), manifest refraction, corneal haze, and postoperative pain were reviewed in LASEK and epi-LASIK treated eyes at 3 months after the operation. RESULTS: At one week after surgery, UCVA was recovered more rapidly after epi-LASIK than LASEK (LASEK: 0.61+/-0.23, Epi-LASIK: 0.79+/-0.11, p<0.05), but UCVA at both 1 and 3 months showed no significant difference between the LASEK and epi-LASIK groups. However, epi-LASIK-treated eyes had lower postoperative pain scores and lower corneal haze scores (1 month; p=0.01) than those of LASEK-treated eyes. CONCLUSIONS: Epi-LASIK showed a more rapid visual recovery than LASEK at 1 week after surgery for the correction of myopia. Epi-LASIK-treated eyes also had less postoperative pain and an earlier reduction of postoperative corneal haze. These results suggest epi-LASIK could be a viable alternative procedure for the correction of moderate to high myopia.