Comparison of Epi-LASIK and Off-Flap Epi-LASIK for the Treatment of Low and Moderate Myopia
Received 14 April 2008; received in revised form 8 August 2008; accepted 8 August 2008.
Purpose
To compare the early postoperative course and the 1-year clinical results of off-flap Epi-LASIK and Epi-LASIK for the treatment of low and moderate myopia.
Design
Pilot double-masked, randomized, comparative study.
Participants
Fifty-six patients (112 myopic eyes).
Methods
Epithelium was separated in all eyes with the use of Centurion SES epikeratome (Norwood Abbey EyeCare, Vic, Australia). The first eye treated and surgical method in the first eye were randomized. One eye of each patient underwent standard Epi-LASIK, whereas in the contralateral eye, the epithelial sheet was not retained on the photoablated stroma (off-flap Epi-LASIK eyes). Mean preoperative spherical equivalent was −3.50±1.22 diopters (D; range, −1.75 to −6.37 D) in Epi-LASIK eyes and −3.61±1.22 D (range, −1.50 to −6.50 D) in off-flap Epi-LASIK eyes (P>0.05, paired Student t test). Excimer laser corneal ablation was performed using the Allegretto 200Hz (Wavelight Laser Technologie AG, Erlangen, Germany). Patients were followed up daily until the epithelial healing was complete and at 1, 3, 6, and 12 months.
Main Outcome Measures
Epithelial healing time, subjective pain score, and uncorrected visual acuity (UCVA) were evaluated during the first postoperative days. Uncorrected visual acuity, spherical equivalent refraction, best spectacle-corrected visual acuity, haze scores, and wavefront aberrations were recorded at all subsequent intervals.
Results
Time of epithelial healing did not differ significantly in Epi-LASIK and off-flap Epi-LASIK eyes (4.76±0.84 days in Epi-LASIK eyes vs. 4.54±0.93 days in off-flap Epi-LASIK eyes). No significant difference in UCVA was found after the 2 techniques during the first postoperative days. Subjective pain score was lower in off-flap Epi-LASIK eyes at 2 postoperative hours, whereas no significant difference in pain scores was noted between the 2 techniques at the other intervals. There was no significant difference in spherical equivalent, line gain or loss, haze scores, and higher-order aberrations between Epi-LASIK and off-flap Epi-LASIK eyes at any interval. Uncorrected visual acuity was significantly better in Epi-LASIK eyes only at 6 months (−0.05±0.08 in Epi-LASIK eyes vs. 0.00±0.07 in off-flap Epi-LASIK eyes). Preoperative wavefront aberrations did not change significantly 1 year after either procedure.
Conclusions
Epi-LASIK and off-flap Epi-LASIK had equal visual and refractive results for the treatment of low and moderate myopia in this study.
Financial Disclosure(s)
Proprietary or commercial disclosure may be found after the references.
1Institute of Vision & Optics (IVO), Crete, Greece
2Department of Ophthalmology, University Hospital of Heraklion, Crete, Greece
Correspondence: Maria I. Kalyvianaki, MD, PhD, Institute of Vision and Optics, Medical School, University of Crete, Crete, Greece
Manuscript no. 2008-465.
Financial Disclosure(s): The author(s) have made the following disclosure(s): Ioannis G. Pallikaris is a patent holder of the Centurion SES epikeratome (Norwood Abbey, Australia). The rest of the authors have no financial interest in any device or instrument reported herein.
ABSTRACT