影响LASIK术后不同时期屈光状态改变的因素分析

Analysis of factors influencing the change of refractive state at different stages after LASIK

目的分析超高度近视患者LASIK术后中远期屈光状态的变化及其影响因素。方法采用回顾性研究,选择LASIK术后患者99人(166眼),术前等效球镜值:-8.5D~-15.5D,平均(-12.12±2.82)D,分别记录术前、术后的视力、屈光度、角膜厚度、眼轴等指标,分析屈光状态改变与上述因素之间的关系。结果(1)裸眼视力:术后6月~1年时趋于稳定,达0.85±0.22(2)屈光度:术后屈光度由正向负逐渐变化,术前屈光度越高,术后的屈光度变化越大。(3)角膜厚度及曲率:术后这两项指标在2年内增加较快(术后屈光度与角膜厚度增长呈负相关r=-0.193,P=0.044;r=-0.233,P=0.024),3年至5年趋于缓慢。(4)眼轴:术后3年和5年的屈光回退与其眼轴长呈明显相关性(P=0.023,P=0.001;P=0.01,P=0.004)。结论角膜增厚引起的角膜曲率改变是导致超高度近视患者LASIK术后早、中期屈光回退的主要原因,远期以眼轴增长产生新的近视为主。

Objective:To study the influence factors of mid-and long-term refractive change for ultra-high myopi-a patients after laser in situ keratomileusis(LASIK).Methods:A retrospective study was conducted of the records of 99 patients(166eyes)undergoing LASIK for correction of ultra-high myopia(spherical equivalent-12.12±2.82 D;range,-8.50 to-15.5D).The visual acuity(VA),diopter,central corneal thickness(CCT),and axial length was measured preoperatively and postoperatively.The relationship between the refractive change and the influence factors mention above were analyzed.Results:(1)UCVA Postoperative uncorrected visual acuity reached 0.85±0.22at 6 months to 1 year after operation,.(2)Diopter:The refractive status of patients changed from hyperopia to myopia dur-ing follow-up.The higher the preoperative refraction,the greater the postoperative refraction change was.(3)CCT and corneal curvature:They increased rapidly within 2 years after operation(Postoperative refraction was negatively cor-related with corneal thickness increase r=-0.193,P=0.044;r=-0.233,P=0.024)and then tended to be slow from 3 to 5 years after operation(4)Axial length:refractive regression and diopter at 3 years and 5 years after operation were significantly correlated with axial length(P=0.023,P=0.001;P=0.01,P=0.004.)Conclusion:After LASIK,the corneal curvature caused by corneal thickening changes is the main reason for early and mid-term refractive regres-sion and the long-term is due to the axial growth of new myopia-based.