准分子激光屈光性角膜切削术治疗中低度近视眼

Results after using the 193nm excimer laser for photorefractive keractectomy in mild to moderate myopia

目的探讨准分子激光屈光性角膜切削术（photorefractivekeractectomy，PRK）治疗中低度近视眼的疗效。方法233只中低度近视眼用PRK治疗并随访1a，角膜地形图观察角膜前表面屈光力和形态变化，对术后屈光回退和角膜雾浊进行临床研究。结果术后1a裸眼视力0．8以上眼占92％，屈光回退超过－1．00D眼占7．30％；术后1～3mo0．5～1级角膜雾浊眼占11．16％，术后1a0．5级雾浊眼占3．00％。角膜地形图显示平均角膜屈光力（ACP）术后无变化；角膜表面规则指数SRI和不对称指数（SAI）术后1mo时增高，但术后6mo和12mo无差异；角膜不规则散光指数（IAI）术前后无变化。结论PRK治疗中低度过眼疗效好，屈光稳定性高，对角膜表面形态影响小，术后角膜雾浊随时间推迟逐渐减轻或消失。

To investigate the results after using the193nm excimer laser for photorefractive keractectomy (PRK)in mild to mederate myopia.Methods: 233 eyes of mild to moderate myopia weretreated with PRK and followed - ups 1a. The change ofcorneal surface refractive and shapes were detected by cornealtopography. The refractive regression and corneal 'Haze'were studied by clinical evaluation.Results: 1a after PRK, 92 % myopia of uncorrective visual acuity were greater than 0. 8, only 7. 30% eyes of refractive regression were greater than- 1. 00 D. 11.16 %corneal 'Hare' was 0. 5 - 1 scale in 1 to 3 months afterPRK, but 3. 00% was 0. 5 scale in 1a after PRK. Cornealtopography showed that average corneal powers (ACP) hadno change after PRK ; surface regular indexes(SRI) and surface asmpmetry indexes (SAI) were increased in 1mo afterPRK, but no change between 6 mo and 12 mo; Irregularastigmatism indexes (IAI) had no change between beforePRK and after PRK.Conclusions: Results for mild to moderate myopia withPRK were good and high refractive stability. The influenceson corneal surface shapes were small after PRK and corneal'Haze' was decreased or disapeared as the long time folowed-ups.