Basic And Clinical Study Of Both-sided Laser In Situ Keratomileusis For Myopia

Objectives: To investigate the effects of Both-sided laser in situ keratomileusis on the corneal wound healing in rabbits and evaluate the safety, effect and stability of BSL for treatment of myopia.Methods: 1.We choose twenty-four adult New Zealand white rabbits as animal model. LASIK were performed on right eyes to attempt a correction of–3.00D and BSL were performed on left eyes to attempt a correction of–3.00D also. All the rabbits were examined with slit-lamp microscope and in vivo confocal microscopy before surgery and at 1 day, 1 week, 1 and 3 months after surgery. At each time of post operation examination, six operated rabbits were killed randomly, and all the corneas were removed for histopathological observation of transmission electron microscopy and light microscopy.2.thirty-six eyes from eighteen patients with BSL and forty-eight eyes from twenty-four patient with LASIK were included in this study. The uncorrected visual acuity, best corrected visual acuity, refraction, aberration, topograghic features, functional acuity contrast testing were performed preoperatively and 1 week, 1 month, 3 months postoperatively for each case.Results: 1.The slit-lamp microscopy examination showed no Haze post operation. A part of corneas have growing epithelial rings at the flap margins both after LASIK and BSL. The ultrastructure changes of corneal epithelium, epithelial basement, collagen and fibroblast cell after BSL were analogy with LASIK. 2. The injury index and bear index were lower than that of regular procedure of LASIK (P<0.01). The uncorrected visual acuity in all eyes after surgery achieved or exceeded the preoperative best corrected visual acuity (BCVA), no serious complication occurred to threaten visual acuity. 1 week after surgery, almost all of the spherical equivalent (SE) dioptre of two groups were hyperopic. But with time, refraction moved to myopia. Cornea topography is regular configuration after surgery in two groups. In the OPD exam, the total aberrations postoperatively were less than that preoperatively. High order aberrations increased immediately after surgery in two groups, but decreased with time and did not return to preoperative values after 3 months(P<0.05). Spherical were larger than that preoperatively in two groups. Coma were not increased or decreased after surgery in two groups. CSF obviously decreased for all spatial frequencies 1 week post- operatively and restored to pre-operative level for some spatial frequencies 3 months postoperatively.Conclusion: 1.The corneal wound healing response was slight after BSL. And the extend after BSL was similar with after LASIK 2. BSL is a safe and effective method and appears another good choice for correcting myopic.