Clinical investigation of off-flap epi-LASIK for moderate to high myopia.
OBJECTIVE
To compare the clinical outcome of on-flap and off-flap epi-LASIK for moderate to high myopia.


METHODS
This prospective, observer-masked, randomized study included 62 eyes of 31 patients with myopia who underwent off-flap epi-LASIK (epikeratome; Moria, Antony, France) in one eye (off-flap group) and on-flap epi-LASIK in the contralateral eye (on-flap group). Corneal ablation was performed with a commercially available laser (Mel-80; Carl Zeiss Meditec, Oberkochen, Germany). Patients were seen at 3, 5, and 12 days and 1 and 3 months after surgery. Clinical outcomes were compared between groups.


RESULTS
No significant between-group differences in the mean preoperative spherical equivalent (-6.18 +/- 1.29 D vs. -6.47 +/- 1.70 D), the change in lines of best corrected visual acuity at 3 months after surgery, and postoperative pain were found. Compared with the on-flap group, outcomes of better uncorrected visual acuity at 3 and 5 days after surgery (P < 0.001), rapider reepithelialization (P < 0.001), and lower level of haze at 1 and 3 months after surgery (P = 0.04, 0.04) were found in the off-flap group. Three months after surgery, contrast sensitivity function (CSF), with and without glare, did not differ from before surgery in both groups (P > 0.05) except CSF at 18 cpd with glare increased significantly in the off-flap group 3 months after surgery (P = 0.04). Wavefront aberration increased significantly from baseline in both groups 3 months after surgery (P < 0.05). The on-flap group revealed greater but insignificant increasing amplitude in wavefront aberration compared with the off-flap group.


CONCLUSIONS
In comparison with on-flap epi-LASIK, off-flap epi-LASIK offers comparable postoperative pain, a lower level of haze formation, a rapider visual recovery, and better visual quality. Further investigations of a larger number of subjects and longer follow-up periods are warranted.
Affiliated Eye Hospital, Wenzhou Medical College, Zhejiang, Peoples Republic of China.
Qin-Mei
QM
Wang
Ai-Cun
AC
Fu
Ye
Y
Yu
Chen-Chen
CC
Xu
Xiao-Xing
XX
Wang
Shi-Hao
SH
Chen
A-Yong
AY
Yu
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / Q000601:surgery*; D004311:Double-Blind Method; D019573:Epithelium, Corneal / Q000502:physiology; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000601:surgery*; D010149:Postoperative Pain; D011446:Prospective Studies; D013524:Surgical Flaps; D014065:Tonometry, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014945:Wound Healing / Q000502:physiology