角膜塑形镜去片裸眼视力低下的影响因素及近视控制效果

目的：探讨配戴角膜塑形镜6个月后去片裸眼视力低下的影响因素及近视控制效果。方法：回顾性系列病例研究。收集2015年4月至2017年1月于北京同仁医院验光配镜中心验配角膜塑形镜并随访至少6个月的青少年儿童，以去片后即刻裸眼视力能否达到0.8为标准将入选儿童分为2组。比较2组间年龄、视力、屈光度、眼压、角膜曲率、e值、角膜直径、瞳孔直径、非对称性指数、规则性指数的异同，以及对近视的控制效果。采用单因素及多因素线性回归分析去片裸眼视力的影响因素。结果：共50例（96眼）入组，年龄（10.6±2.4）岁，球镜度（-3.62±1.18）D，柱镜度（-0.33±0.43）D，眼轴长度（25.18±0.75）mm。其中裸眼视力≤0.8组52眼，裸眼视力>0.8组44眼，通过单因素分析，较差的裸眼视力与基础较长的眼轴长度（b=-0.09，β=-0.29，P=0.003）、较高的球镜度（b=0.07，β=0.36，P<0.001）、较高的柱镜度（b=0.12，β=0.22，P=0.030）有关。通过多因素线性回归分析，较差的裸眼视力与基础较高的球镜度（b=0.05，β=0.27，P=0.018）有关。6个月后裸眼视力≤0.8组儿童眼轴增长（0.07±0.15）mm，裸眼视力>0.8组儿童眼轴增长（0.11± 0.15）mm，差异无统计学意义。结论：影响角膜塑形镜去片裸眼视力的主要因素是屈光度和眼轴长度，屈光度越高、眼轴越长，去片后裸眼视力越差，但其对近视仍有较好的控制作用。

Factors Associated with Low Visual Acuity after Orthokeratology Lens Removal and Myopia Control

Objective: To assess the factors associated with low visual acuity after orthokeratology lens removal and the efficacy of myopia control. Methods: This was a retrospective study. Children who were examined and followed up for at least 6 months at Tongren Eye Care Center during April 2015 and January 2017 were enrolled in the study. Participants were divided into two groups based on their uncorrected visual acuity (UCVA) after removing orthokeratology lenses. Age, visual acuity, refraction,intraocular pressure, corneal curvature, e value, corneal diameter, pupil diameter, and axial elongation were compared between groups. Univariate and multivariate regression analysis were conducted to assess the factors associated with visual acuity. Results: Fifty children (96 eyes) participated in the study, with 52 eyes in the group with UCVA≤0.8 and 44 eyes in the group with UCVA>0.8. Mean agewas 10.6±2.4 years. At baseline, mean spherical refraction was -3.62±1.18 D; mean cylinder refraction was -0.33±0.43 D; mean axial length was 25.18±0.75 mm. Using univariate analysis, and worse visual acuity was associated with longer axial length (b=-0.09, β=-0.29, P=0.003), higher spherical refraction (b=0.07, β=0.36, P<0.001), and higher cylinder refraction (b=0.12, β=0.22, P=0.030) at baseline. Using multivariate linear analysis, worse visual acuity was only associated with higher spherical refraction (b=0.05, β=0.27, P=0.018) at baseline. Axial elongation was 0.07±0.15 mm in the group with VA≤0.8 and 0.11±0.15 mm in the group with VA>0.8, the difference was not significant. Conclusions: Longer axial length and higher spherical refraction are the main factors associated with visual acuity after orthokeratology lens removal. Despite worse visual acuity, myopia control is still effective.