| Laser in situ keratomileusis(LASIK) has been adapted to correct myopia in our country for about 6 to 7 years, compared with photorefractive keratectomy(PRK), Laser in situ keratomileusis (LASIK) involves the performing of an anterior cornea! flap (130μm~160μm of thickness) and removal of midstromal tissue by excimer laser photoablation. The preservation of the corneal epithelium, Bowman's layer and the most parts of anterior stroma makes LASIK safe and effective. Since 1990s it became the first choice of myopic correction. Although the good refractive results have been clearly demonstrated, few articles have been published regarding the wound healing process after LASIK and most of them confined to animal trial and organ cultured cornea. Recently, technological advances led to the development of powerful clinical confocal microscope which allows observation of the living human eye in situ at the cellular level. The confocal microscopy in vivo is an acceptable and reproducible method to detect the changes of corneal stroma and sublayer thickness. It is especially useful in the area of corneal refractive surgery, where it aids to detect the subtle short and long term changes in cornea.When correcting high myopia (refractive error>=10D), people have different views, for the corneal pachymetry is more thinner, and laser ablation is more deeper than low and moderate myopia, the complications rate increases after LASIK. This study evaluates the changes before and after LASIK at cellular level prospectively, analyzes the affecting factors, discusses the wound healing process and the probable method to prevent the complications about it.In this study, 54 eyes of 31 patients (mean preoperative refraction range: -10D to -18.00D) were analyzed. All the patients were examined before LASIK, 1 day, 1week,l month,3 month after LASIK ,48 eyes were also examined 6 months after LASIK. All the scan were reviewed and analyzed. The visual acuity and refractive changes were also analyzed. Results are as following:1. Uncorrected visual acuity evidently increased after LASIK, and uncorrected visual acuity 6 months postoperatively increased compared with the best corrected visual acuity before surgery. The differences were statistically significant.2. spherical refractive diopter changed markedly from 1 day postoperatively to 1 week, decreased gradually afterwards, and didn't reach a steady state till 6 months postoperatively. The change of spherical refractive diopter negatively correlated with thickness of the epithelium. Astigmatism decreased at 6 months after surgery compared with that before surgery. The differences were statistically significant.3. For high myopia the corneal patchmetry is more thinner, and cell count in anterior stroma, posterior stroma and endothelium is less than that of low and moderate myopia, and the differences were statistically significant. Pleomagthism of endothelium increased and polymagthism decreased compared with low and moderate myopia, The differences were statistically significant.4. After LASIK some patients may have neurotrophic epitheliopathy which may affect visual acuity or not, and disappeared about 6 months postoperatively. 1 week after LASIK, deposits were seen at the basal cells layer, and its area and reflection intensity increased with tune till 6 months, we didn't find it affect visual acuity.5. Nerve fiber could be seen 1 day after LASIK the same as that before surgery, but most of them disappeared 1 week later, the number of nerve fiber increased but didn't reach the level before surgery till 6 months postoperatively.6. Microfolds exiting at the anterior stroma and Bowman's layer. It didn't change with time and correlated with the irregular astigmatism after LASIK. High and low reflection intensity particles were seen at the corneal flap and stromal bed interface, and the total intensity level decreased with tune and became stead at 6 months postoperatively.7. Acellular area were observed at above and below the interface, and its thickness didn't change w...
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