| Purpose: To study the changes of corneal topography and Morphologic changes to analyze the contribution in operation and clinical effects after excimer Laser Assisted In-situ Keratomileusis (LASIK) for high myopia correction.Methods: 58 eye's of 29 cases with myopia undergone LASIK was examined with uncorrected visual acuty(UCVA) , best corrected visual acuty(BCVA) ,diopter and corneal topography preoperatively and 1 month ,3month and 6 month postoperatively .Results: Before lasik ,the percentage of corneal topographic pattern including symmetric bow tie pattern and asymmetric bow tie pattern 38eyes,round pattern and ellipse pattern 18eyes, others as irregular pattern 2eyes was 65.51%, 31.03%, 3.45% respectively.and the probability of myopia complicated with astigmatism on symmetric bow tie pattern and asymmetric bow tie pattern is more than other patterns.The percentage of corneal topographic pattern after 1,3 month including smooth pattern was 82.76%,89.66%,93.10% respectively which was relatively stable, and the other pattern was seldom. No central islet was found. Artherectomy shape become regulating gradually. Vision acuty in smooth pattern is better than the other patterns. There are 2 cases whose UVCA in 6 month postoperation lower than BCVA preoperation are kidney pattern.The percentage of UCVA exceed and equal to 1.0 at l,3,6month after Lasik was 100%,96.56%,93.1% respectively .The dioptor after lasik was amendment evidently and turned to be stable at 3 month after Lasik.Simulated keratometer value (Simk) either isoeffect or the phase contrast one are decreased conspicuously after surgery,they tend to increased gradually slowly with the time going and was stable at 3 to 6 month later.Conclusion: Examination and analysis on the corneal topography before and after lasik can clearly display the morphological changes of the corneal surface morphology,which helps carry out lasik individually and then achieve perfect refractive correction. |
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