中文摘要：

【目的】探讨过夜配戴角膜塑形镜（OK镜）治疗青少年轻度、中度及高度近视的效果差异。【方法】前瞻性病例研究。收集54例（107眼）青少年近视患者，平均年龄（11．6±2．4）岁，按患者戴镜前等效球镜度分为低度近视组（51眼，-0．75- -3．00D）、中度近视组（36眼，-3．25- -5．00D）及高度近视组（20眼，-5．25- -9．00D）。观察配戴前1天及配戴1年后3组内及组间等效球镜度、中央角膜厚度、角膜曲率、前房深度和眼轴变化。【结果】轻度近视组、中度近视组及高度近视组基线平均等效球镜度（D）分别为-2．15±0．63、-4．20±0．54和-6．63±1．18；三组基线眼轴（mm）分别为24．50±0．66、25．16±0．65及26．35±0．87。三组患者基线中央角膜厚度、前房深度、中央角膜K值、平K值及陡K值差异均无统计学意义。戴镜1年后3组眼轴增长值（ram）分别为0．22±0．27、0．09±0．22和0．02±0．22；其中低度近视组与中度近视组、高度近视组相比，组间眼轴增长值差异有统计学意义（P值分别为0．04、0．008），中度近视组与高度近视组两组间眼轴增长值差异无统计学意义（P值为0．35）。三组戴镜1年后等效球镜度显著下降，3组内差异均有统计学差异（t9均〈0．0001），低度近视组与中度、高度近视组间差异具有统计学意义（P均〈0．0001）。1年前后3组中央角膜K值、平K值、陡K值均明显变平坦，组内差异比较均有统计学差异（P均〈0．0001）。中央角膜厚度、前房深度及角膜直径1年前后差异无统计学意义。【结论】中高度近视者采用角膜塑形镜控制近视的作用较低度近视更优。角膜曲率改变的量可能是影响OK镜近视治疗效果的主要因素之一。

英文摘要：

[Objective ] This prospective study was conducted to assess the influence of overnight orthokeratology （OK） on low, middle and high myopia in southern Chinese teenagers. [Methods] Fifty-four subjects （107 eyes, age 11.65±2.44 years, mean±SD） who matched the inclusion criteria for OK were enrolled in the study. The subjects were divided into three groups according to the different refraction baseline （low myopia group： 0.75±3.00 D, 51 eyes; middle myopia group： 3.25±5.00 D, 36 eyes; high myopia group ： 5.25 - 9.00 D, 20 eyes ）. Refraction, central corneal thickness, corneal keratometry, anterior chamber depth and axial length （AL） were measured at baseline and after 1 years using ocular biometry. The changes were evaluated and compared among the groups. Results were analyzed by SPSS 17.0 software. [ Results ] Fifty-four subjects （total 107 eyes） completed the 1-year follow-up examinations. At baseline, the spherical equivalent refractive error （SER） was -2.15 D ± 0.63 D, -4.20 D ± 0.54 D, and -6.63 D ±1.18 D in three groups. The axial length was （24.50 ± 0.66） mm, （25.16 ± 0.65） mm, and （26.35 ±0.87） mm in the three groups, respectively. There were no significant differences among the groups in initial central corneal thickness, anterior chamber depth, central, flat and steep kerotometry. The increase in axial length during the 1-year study period was （0.22 ± 0.27） ram, （0.09 ± 0.22） mm and （0.02 ± 0.22） mm in three groups, respectively, and the difference was significant between low myopia group and middle myopia group （P = 0.04）, low myopia group and high myopia group （P = 0.008） , whereas no significant difference was found between middle myopia group and high myopia group （P = 0.35 ）. Spherical equivalence decreased dramatically in three groups after one year （all P 〈 0.0001 ）. And the difference was significant between low myopia group and middle myopia group （P 〈 0.0001 ）, low myopia group and high myopia group （P ?