Evaluation of Enhancement after LASIK

Objective To investigation the effectiveness,safety and feasibility of enhancement after LASIK in myopia,retrospectively analysis the 5752 cases.Methods From November 2000 through November 2002,the patients loss UCVA examined refraction monthly in 5752 cases undergone LASIK.The refraction was steady continutly 3 months.To measure the cornal thickness and corneal topography.The patients undergone enhancement were examined at postoperative 1 day、1 week、2 weeks、1 month、3 month、6 month、1 year and 2 years.Results 97 patients were enhanced amony 5752 myopia cases.There were 68 patients in high myopia and 29 patients in middle myopia.High myopia were 70.1%;middle myopia were 29.9%.The 78.7% patients were multi-optical zone ablation in high myopia,the middle myopia was 3.4%.The mean time was 3.335 months that the uncorrected visual acuity was oss in high myopias,the middle myopia mean time was 3.196 months.Thre mean UCVA was 4.7±0.21 in high myopia,the middle myopia was 4.8±0.15.The mean sphere needed correction was -2.531D,(dioptor),cylinder was -0.815D,in high myopia;The sphere was -1.288D,cylinder was -0.796D.There was main irregular astigmatism.The mean UCVA after enhancement was 5.03±0.13 in high myopia,the middle was 5.08±0.09.The interval time between two operation was 7.698 months in high myopia and was 10.747 months in middle myopia.The corneal thickness before enhancement was 456.753μm in high myopia and 485.451μm in middle myopia.The mean corneal curvature in creased 1.89D in high myopia ad 0.77D in middle myopia after LASIK.There were statiscally significant difference in the increasing k.values.The epithelial ingrowth was 5.9% in high myopia and 6.9% in middle myopia.There wasn′t infection and diffus lamellar keratitis(DLK).Conclusions The enbancement was safe and effective after LASIK for under-correction,over-correction and regression.