To perform the external validation of a model to predict postoperative axial length (AL) in children over 2 years of age who were undergoing bilateral cataract surgery with primary intraocular lens (IOL) implantation. Validation study using a retrospective case series. Using a population different from the one that created the model, but with the same characteristics regarding age, bilateral cataract, primary IOL implantation, and follow-up assessment, AL was estimated. The AL values estimated by the model were compared with the AL measured in the follow-ups. In all, 55 eyes of 30 children were selected for this study; in 5 children with bilateral cataracts, only 1 eye was included. The median age at the time of surgery was 5.01 years. Follow-up AL measurements were obtained for 179 visits. The median age at the final follow-up visit was 10.15 years. The median AL measured and estimated by the model in all visits were 22.37 mm and 22.16 mm, respectively (Pearson coefficient: 0.9534; Lin correlation: 0.9258). In the Bland–Altman analysis, the 95% limit of agreement between the 2 methods (measured and estimated AL) was 0.71 to −1.19. In 3 eyes (1.68%) with AL shorter than 21.2 mm, the difference was >0.71, and in 9 eyes with AL longer than 22.5 (5.03%), it was less than −1.19. The median AL measured and estimated at the final visit were 22.69 mm and 22.43 mm, respectively. Our previously developed prediction model for globe AL growth demonstrated good external validity by accurately predicting measured AL changes with growth in the validation cohort.

中文翻译：

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预测双侧白内障手术后儿童术后眼球轴长的模型的外部验证

对模型进行外部验证，以预测 2 岁以上接受双侧白内障手术并植入人工晶状体 (IOL) 的儿童术后眼轴长度 (AL)。使用回顾性病例系列进行验证研究。使用与创建模型的人群不同但在年龄、双侧白内障、初次人工晶状体植入和随访评估方面具有相同特征的人群来估计 AL。将模型估计的 AL 值与后续测量的 AL 值进行比较。总共选取了 30 名儿童的 55 只眼睛进行这项研究；在 5 名患有双眼白内障的儿童中，仅包括 1 只眼睛。手术时的中位年龄为 5.01 岁。对 179 次就诊进行了后续 AL 测量。最终随访时的中位年龄为 10.15 岁。模型在所有就诊中测量和估计的中位 AL 分别为 22.37 mm 和 22.16 mm（Pearson 系数：0.9534；Lin 相关性：0.9258）。在 Bland-Altman 分析中，两种方法（测量的 AL 和估计的 AL）之间的 95% 一致性极限为 0.71 至 -1.19。在 AL 短于 21.2 mm 的 3 只眼（1.68%）中，差异 >0.71，在 AL 长于 22.5 毫米的 9 只眼（5.03%）中，差异小于 -1.19。最后一次就诊时测量和估计的中位 AL 分别为 22.69 毫米和 22.43 毫米。我们之前开发的全球 AL 增长预测模型通过准确预测测量的 AL 随着验证队列的增长而发生的变化，表现出良好的外部有效性。