Abstract:

Objective   To investigate the influence on postoperative response,effectiveness and complications of high myopia(≥-6.00D) by removing or reserving the corneal epithelial flap during epipolis laser in situ keratomileusis( Epi-LASIK). Methods   A series of 40 patients(80 eyes) with high myopia who would prospectively undergo Epi-LASIK in our centre were studied. After getting the agreement of each patient, one eye randomly had on-flap Epi-LASIK(on-flap group) and the other eye had off-flap Epi-LASIK(offflap group). All eyes wore bandage contact lens after operation. Corneal irritation symptoms and time of epithelial healing were observed at 3rd and 5th after operation. Naked visual acuity at the 1st week, 1st and 6th month and postoperative corneal haze at the 1st and 6th month after Epi-LASIK were statistically compared between the two groups. Results   There were fewer corneal irritation symptoms in the offflap group on the 3rd and 5th day after the operation than in the on-flap group(P＜0.05).  The time of epithelial healing in the off-flap group and the on-flap group was (2.96±0.51) days and (4.92±1.38) days respectively， and there was significant difference between the two groups(P＜0.05). At the first week after the  operation, the naked visual acuity of the off-flap group was better than the on-flap group, and there was significant difference between the two groups(P＜0.05). There was no statistical difference between the two groups in terms of naked visual acuity at the 1st and 6th month after the operation respectively(P＞0.05). On the developing of corneal haze after the operation, there was statistical difference between the two groups at the 1st and 6th month(P＜0.05). Conclusions   Although the off-flap Epi-LASIK can relieve corneal irritation symptoms and shorten epithelial healing time,at the same time it can increase the development of corneal haze in patients with high myopia. So reserving the epithelial flap in high myopia patients is suggested.

Key words: Epi-LASIK; Corneal epithelial flap; High myopia; Epipolis laser