[The effects on corneal wound healing of LASIK with ultra-thin corneal flaps and LASEK in rabbits].
OBJECTIVE
To evaluate the corneal wound-healing response of LASIK with ultra-thin corneal flaps and LASEK in rabbits.


METHODS
It was an experimental study. Thirty-two adult New Zealand rabbits were divided into 2 groups with 16 each. Two surgical procedures, LASIK with ultra-thin corneal flaps and LASEK were performed on the right eye of each group, with the left eye as control. A myopic ablation of 10 diopters was performed in each group. Corneal wound-healing and histopathological changes of the ablation zone were studied through slit lamp, light microscope and transmission electronic microscope. The expression levels of collagen I , collagen III, fibronectin (FN) and transforming growth factor beta-1 (TGF-beta1) were investigated by immunohistochemistry and RT-PCR assays.


RESULTS
In the group of LASIK with ultra-thin corneal flaps, the corneas were clear without haze followed by slight wound healing and fast recovery. While in the group of LASEK, corneal wound healing was obviously delayed. There was haze in grade 1 (62.5%) and grade 2 (37.5%) in 1 month, with grade 0.5 (43.75%) and grade 1 (56.25%) in 3 months. 1 month and 3 months after surgery, proteins and mRNA of collagen III, FN and TGF-beta1 were expressed in the anterior corneal stromal layer in each group. But the expression was much higher in the group of LASEK (t = 18.47, 11.98, P < 0.05). The protein and mRNA expression of collagen I had no difference between the two groups (t = 0.72, 0.36, 0.47, 2.38, P > 0. 05). The mRNA expression of collagen I, collagen III, FN and TGF-beta1 had no statistical difference between the groups of control and LASIK with ultra-thin flap in 3 months (t = 2.42, 1.54, -0.83, P > 0.05).


CONCLUSIONS
According to the animal experiments, it was suggested that the corneal wound-healing response of LASIK with ultra-thin corneal flaps was much better than that of LASEK.
Zou
Jun
J
Department of Ophthalmology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.
Chu
Ren-Yuan
RY
Zhou
Xing-Tao
XT
Dai
Jin-Hui
JH
D000818:Animals; D003315:Cornea / Q000601:surgery*; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D011817:Rabbits; D014945:Wound Healing