青少年近视患者配戴角膜塑形镜5年的有效性及安全性

目的　评价青少年近视患者长期配戴角膜塑形镜延缓近视进展的有效性及其对角膜的安全性。方法　回顾性病例系列观察研究。选取2012年1月至2013年12月于天津市眼科医院视光中心配戴角膜塑形镜且连续配戴5 a的153例（153眼）青少年近视患者，分别于戴镜前及戴镜后1 a、2 a、3 a、4 a、5 a采用裂隙灯显微镜评估角膜状态，采用光学生物测量仪检测眼轴长度，采用角膜内皮细胞计数仪测量中央角膜厚度、角膜内皮细胞密度、角膜内皮细胞面积、六边形细胞比例及角膜内皮细胞面积变异系数等，并对所得数据进行分析。结果　配戴角膜塑形镜前后裸眼视力及等效球镜度数差异均有统计学意义(F=442.515、415.389,均为P<0.001)。青少年近视患者配戴角膜塑形镜后眼轴增长速度平均为每年0.16 mm。戴镜5 a中，64眼(41.83％)发生不同程度的并发症，其中70.31％为1级或2级角膜点状染色。与戴镜前中央角膜厚度相比，戴镜后不同时间的中央角膜厚度均变薄，差异均有统计学意义（均为P<0.05）。与戴镜前相比，配戴角膜塑形镜5 a角膜内皮细胞密度及内皮细胞面积均无显著变化（F=0.328、0.735，均为P>0.05）；但六边形细胞比例显著降低（F=12.020，P<0.001），角膜内皮细胞面积变异系数显著增高（F=23.016，P<0.001）。结论　青少年近视患者长期配戴角膜塑形镜可获得良好的裸眼视力,且可有效延缓眼轴增长速度，长期戴镜未引起严重的角膜或结膜并发症,对角膜内皮细胞、中央角膜厚度影响均甚微。

Efficacy and security of orthokeratology lens on myopia progression in teenagers for 5 years

Objective　To evaluate the efficacy and security of long-term orthokeratology in myopic adolescents.Methods　A retrospective case series observation study was adopted. Totally one hundred and fifty-three patients (153 eyes) of juvenile myopia who were wearing orthokeratology (ortho-k) lens for five years were chosen between January 2012 and December 2013 from Tianjin Eye Hospital Optometry Center. The health of cornea, axial length, central corneal thickness (CCT), corneal endothelial density, percentage of hexagonal cells and the coefficient of variation were measured before and after 1 year, 2 years, 3 years, 4 years, 5 years of wearing ortho-k lens. All parameters were tested by normal test and evaluated by repeated measurement one-way ANOVA.Results　There were significant differences in uncorrected visual acuity and spherical equivalent before and after wearing an ortho-k lens (F=442.515, 415.389, both P<0.001). The axial growth rate of myopia was 0.16 mm per year. During 5 years of ortho-k lens wearing, 64 eyes (41.80%) developed complications of varying degrees, among which 70.31% had mild grade 1,2 corneal epithelial staining. Compared with the CCT before lens wearing, the CCT was slightly thinner at each follow up time (all P<0.001). There were no significant changes in the corneal endothelial density and the average area of endothelium before and after 5 years of wearing the ortho-k lens (F=0.328, 0.735, both P>0.05). However, the hexagon ratio of endothelium was significantly decreased (F=12.020,P<0.001) and the coefficient of variation of corneal endothelium was significantly higher (F=23.016, P<0.001).Conclusion　Wearing ortho-k lens for a long period of time in adolescent myopic patients can obtain good uncorrected visual acuity and effectively delay the growth rate of axial length without serious corneal or conjunctival complications. There is little effect on corneal endothelium and central corneal thickness.