[Effect of corneal e-value on myopia control in children and adolescents with orthokeratology].

Objective: To investigate the influence of corneal e-value on the effectiveness of orthokeratology in controlling myopia in children and adolescents. Methods: A retrospective cohort study was conducted, involving the data from 1 563 myopic patients (1 563 eyes) who underwent orthokeratology at the Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine from June 2015 to August 2021 and adhered to lens wear for at least 2 years. The cohort consisted of 737 males and 826 females with an average age of (10.84±2.13) years. Based on corneal e-value parameters obtained from corneal topography, patients were categorized into a low e-value group (n=425) and a high e-value group (n=1 138). Data on gender, age, parental myopia history, and baseline measures such as spherical equivalent (SE), axial length, and corneal e-value were collected. Differences in axial length change and corneal fluorescein staining rates were compared between the two groups at 1 and 2 years after the start of lens wear. A generalized linear mixed model was established with axial length change as the dependent variable to analyze the correlation between axial length change and baseline corneal e-value. Results: The initial age of the 1 563 myopic patients was (10.84±2.13) years, with a baseline SE of (-3.05±1.30) D. After 1 year of lens wear, the axial length change was (0.20±0.19) mm in the low e-value group and (0.24±0.20) mm in the high e-value group. After 2 years, the changes were (0.38±0.25) mm and (0.43±0.27) mm, respectively, with statistically significant differences (all P<0.05). The incidence of corneal staining after 1 year of lens wear was 9.2% (39/425) in the low e-value group and 14.1% (160/1 138) in the high e-value group. After 2 years, the rates were 15.8% (67/425) and 21.8% (248/1 138), respectively, with statistically significant differences (all P<0.05). After adjusting for parental myopia history, age, SE, and baseline axial length, the baseline corneal e-value was positively correlated with axial length change at 1 and 2 years after lens wear (all P<0.05). Conclusions: Corneal e-value is an independent factor influencing the effectiveness of orthokeratology in controlling myopia. A smaller corneal e-value is associated with slower axial length growth after orthokeratology, indicating better control of myopia in treated eyes.目的： 探讨角膜e值对角膜塑形镜控制儿童青少年近视眼效果的影响。 方法： 回顾性队列研究。收集2015年6月至2021年8月在山东中医药大学附属眼科医院验配角膜塑形镜并坚持戴镜满2年的近视眼患者1 563例（1 563只眼），其中男性737例，女性826例，年龄为（10.84±2.13）岁。根据角膜地形图检查结果的角膜e值参数是否>0.5，将患者分为低e值组425例和高e值组1 138例。收集所有患者性别、年龄、父母近视眼情况，以及戴镜前的等效球镜度数（SE）、眼轴长度、角膜e值等数据。比较患者戴镜后1年和2年的眼轴长度变化量和角膜荧光素染色点染发生率的差异。以眼轴长度变化量为因变量建立广义线性混合模型，分析眼轴长度变化量与基线角膜e值等因素的相关性。 结果： 1 563例近视眼患者基线SE为（-3.05±1.30）D。低e值组和高e值组患者戴镜1年后眼轴长度变化量分别为（0.20±0.19）和（0.24±0.20）mm，戴镜2年后则分别为（0.38±0.25）和（0.43±0.27）mm，差异均有统计学意义（均P<0.05）。两组患者戴镜1年后角膜点染的发生率分别为9.2%（39/425）和14.1%（160/1 138），戴镜2年则分别为15.8%（67/425）和21.8%（248/1 138），差异均有统计学意义（均P<0.05）。在调整父母近视眼情况、年龄、SE和基线眼轴长度后，基线角膜e值与戴镜后1年和2年的眼轴长度变化量均呈正相关（均P<0.05）。 结论： 角膜e值为影响角膜塑形镜控制近视效果的独立因素，角膜e值越小，配戴角膜塑形镜后眼轴增长越慢，对于近视眼的控制效果越好。.