Supplementary Material for: Improving Accuracy of In-the-bag Intraocular Lens Power Calculation in Adult Eyes with Unilateral Subluxated Lenses by Using the Anterior Chamber Depth of the Unaffected Eye

Introduction: This study aimed to determine the interchangeability of bilateral anterior chamber depth (ACD) in intraocular lens (IOL) power calculations for cataractous eyes and refractive outcomes using the unaffected fellow-eye ACD in lens subluxation. Methods: The predicted postoperative spherical equivalent (SE) calculated using the Kane formula with and without fellow-eye ACD in 202 cataract patients was compared. Refractive outcomes of the newer formulas (the Kane, Barrett Universal II (BUII), and Pearl-DGS formulas) with affected-eye ACD and with unaffected fellow-eye ACD were compared in 33 eyes with lens subluxation (the affected eye) undergoing in-the-bag IOL implantation. The SD of the prediction error (PE) was assessed using the heteroscedastic method. Results: In 202 paired cataractous eyes, no marked ACD difference was found bilaterally; the predicted SE obtained without the fellow-eye ACD was comparable with that calculated with the fellow-eye one (P = .90), with a mean absolute difference of 0.03 ± 0.03D. With the affected-eye AL, keratometry, and ACD, the median absolute error (MedAE) was 0.38-0.64D, and the percentage of PE within ±0.50D was 30.30-57.58%. The unaffected-eye ACD improved the results (MedAE, 0.35-0.49D; the percentage of PE within ±0.50D, 54.55-63.64%). The SDs of the BUII (0.82D) and Pearl-DGS formulas (0.87D) with the affected-eye ACD were significantly larger than those of the Kane and Pearl-DGS formulas (both 0.69D) with the unaffected-eye ACD. Conclusion: Bilateral ACD was interchangeable in IOL power calculation for cataractous eyes. Unaffected-eye ACD in lieu of affected-eye ACD can enhance the accuracy of newer formulas in patients with unilateral subluxated lenses undergoing in-the-bag IOL implantation.引言：本研究旨在明确白内障眼人工晶状体（intraocular lens, IOL）度数计算中双侧前房深度（anterior chamber depth, ACD）的互换性，以及在晶状体半脱位患者中使用健侧前房深度时的屈光预后效果。 方法：本研究对202例白内障患者分别采用患侧与健侧前房深度，通过凯恩公式（Kane formula）计算术后预测球镜当量（spherical equivalent, SE）并对比二者差异。此外，针对33例接受囊袋内人工晶状体植入术的晶状体半脱位患眼，分别采用患眼前房深度与健侧前房深度，对比新型公式（凯恩公式、巴雷特通用II式（Barrett Universal II, BUII）以及Pearl-DGS公式）的屈光预后结果。本研究采用异方差法（heteroscedastic method）评估预测误差（prediction error, PE）的标准差。 结果：在202例双侧白内障眼中，双侧前房深度无显著差异；不使用健侧前房深度计算得到的预测球镜当量，与使用健侧前房深度的计算结果相当（P=0.90），平均绝对差值为0.03±0.03D。仅采用患眼眼轴长度、角膜曲率与前房深度时，三种新型公式的中位绝对误差（MedAE）为0.38~0.64D，预测误差在±0.50D范围内的占比为30.30%~57.58%。采用健侧前房深度后，预测效果得到改善：中位绝对误差降至0.35~0.49D，预测误差在±0.50D范围内的占比提升至54.55%~63.64%。采用患侧前房深度时，巴雷特通用II式（0.82D）与Pearl-DGS公式（0.87D）的预测误差标准差，显著高于采用健侧前房深度的凯恩公式与Pearl-DGS公式（二者均为0.69D）。 结论：在白内障眼的人工晶状体度数计算中，双侧前房深度具有互换性。对于接受囊袋内人工晶状体植入术的单侧晶状体半脱位患者，采用健侧前房深度替代患侧前房深度，可提升新型公式的计算准确性。