青少年近视配戴角膜塑形镜后非接触眼压的变化

Intraocular pressure changes by Orthokeratology in myopic children

目的观察和分析配戴角膜塑形镜后非接触眼压（NCT）的变化。方法回顾性病例对照研究。对配戴角膜塑形镜的303例青少年近视患者，按照屈光度分为低、中、高度近视组。分别在戴镜前、戴镜后1d、1周、1个月及3个月时测量NCT,角膜曲率以及进行主、客观验光。对相关数据进行连续测量的单因素方差分析，两两比较采用LSD检验。结果配戴角膜塑形镜1周后NCT趋于稳定，并且较戴镜前降低（F=51．75，P〈0．01），但在戴镜后1d，中高度近视眼压分别较戴镜前升高1．04mmHg（t=-4．81．P〈0．01）及0．58mmHg（t=-2．65，P〈0．05），低度近视眼压则呈下降趋势（1=0．57，P〉0．05）。戴镜后3个月．屈光度改变量与眼压改变量呈正相关（r=0．131，P〈0．05），不同程度近视每单位屈光度所致眼压改变不同（F=3．57，P〈0．05）。其中，低度近视每单位屈光度改变导致眼压下降0250mmHg,高于中度近视（t=-2．57，P〈0．01），而低度与高度近视（t=-1．86，P〉0．05）、中度与高度近视（t=0：68，P〉0．05）之间则无明显差异。结论配戴角膜塑形镜后NCT下降，眼压值的下降应该与角膜形态因素以及眼调节功能等因素有关。

Objective To evaluate the changes of intraocular pressure （IOP） in myopic children undergoing overnight orthokeratology treatment. Methods It was a retrospective case-series study. Orthokeratology was performed to correct the refractive errors of 303 eyes of 303 teenagers. The patients were divided into 3 groups： low-myopia, moderate-myopia, and high-myopia, based on the diopters, IOP, corneal curvature and refraction were taken respectively at pre-wear, 1 day and 7, 30, 90 days after orthokeratology. Data were analyzed by repeated-measures ANOVA tests. LSD corrections were performed to compare the differences in IOP if significant differences were found. Results The change of IOP became stable after 1-week orthokeratology treatment, and were significant decrease in lOP after treatment （F=51.75, P〈0.01）. Moderate and high myopia had an increase of 1.04 mmHg （t=-4.81, P〈0.01） and 0.58 mmHg （t=-2.65, P〈0.05） respectively in IOP at 1-day visit, and low myopia only showed a downward trend at the same time （t=0.57, P〉0.05）. Furthermore, the changes in diopters were positively correlated with those in lOP （r=0.131, P〈0.05） 3 months post-treatment. The changes of IOP resulted by one unit change in diopter were significantly different among different degree of myopic group （F=3.57, P〈0.05）. With one unit change in diopter, the low-myopia teenagers showed significantly more reduction in IOP at 0.50 mmHg than moderate-myopia teenagers （t=-2.57, P〈0.01 ）. No significant differences were observed between low- and high-myopia groups （t=-1.86, P〉0.05）, moderate- and high-myopia groups （t=0.68, P〉0.05）. Conclusion Orthokeratology results a decrease in IOP measurements. The observed patterns of IOP changes may be caused cooperatively by the changes in corneal morphology and eye accommodation function.