目的：调查角膜塑形镜对近视儿童脉络膜厚度和脉络膜轮廓的长期影响。方法：受试者来自一项2年的随机对照试验。研究对象为年龄8~12岁、等效球镜在-1.00~-6.00 D的儿童(n=80)，这些研究对象被随机分配到对照组(n=40)和角膜塑形镜组(n=40)。本研究在基线和1、6、12、18、24个月的随访中收集光学相干断层扫描图像(optical coherence tomography,OCT)，然后基于OCT图像计算脉络膜厚度和脉络膜轮廓。在这些随访点也同时测量了眼轴长度(axial length,AL)和其他眼生物学参数。结果：在2年内，对照组的脉络膜厚度随时间变薄，脉络膜轮廓变得更加后凸(均P<0.001)。角膜塑形镜可以改善脉络膜厚度(均P<0.001)，并在所有随访中维持脉络膜轮廓不后凸(均P<0.05)。在角膜塑形镜组中，脉络膜轮廓在颞侧的变化小于鼻侧(P=0.008)，而脉络膜厚度在颞侧以黄斑中心凹为中心、直径3 mm线性扫描区域的增厚更明显(P<0.001)。2年内脉络膜厚度的变化与对照组中2年内AL变化呈负相关(r=-0.52，P<0.001)，然而，这一规律被角膜塑形镜打破(r=-0.05 P=0.342)。在多变量回归模型中校正其他变量后，角膜塑形镜对脉络膜厚度的影响是稳定的。结论：角膜塑形镜可以改善脉络膜厚度并维持脉络膜轮廓，但这种效果在长期内趋于减弱。

Objective: To investigate the long-term effect of orthokeratology on the choroidal thickness and choroidal contour in myopic children. Methods:Subjects were from a conducted 2-year Randomized Clinical Trial. Children (n=80) aged 8-12 years with spherical equivalent refraction of -1.00 to -6.00 D were randomly assigned to the control group (n=40) and ortho-k group (n=40). OCT images were collected at the baseline, 1-, 6-, 12-, 18-, and 24-month visits, then the choroidal thickness and choroid contour were calculated. Axial length (AL) and other ocular biometrics were also measured. Results: During two years, in the control group, the choroidal thickness became thinning and the choroidal contour became prolate with time at all visits (all P<0.001). Ortho-k can improve the choroidal thickness (all P<0.001) and maintain the choroidal contour at all visits (all P<0.05). In the ortho-k group, the choroidal contour was less changed in the temporal than nasal (P=0.008), and the choroidal thickness was more thickening in the temporal 3 mm (P<0.001). Two-year change in choroidal thickness was significantly associated with the two-year AL change in the control group (r=-0.52, P<0.001), however, this trend was broken by ortho-k (r=-0.05, P=0.342). After being adjusted by other variables in the multivariable regression model, the effect of ortho-k on choroidal thickness was stable. Conclusions: In a short term, ortho-k can improve the choroidal thickness and maintain the choroidal contour, but this effect diminished in a long term. Further study with larger sample size and longer follow-up is warranted to refine this issue.