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

Abstract

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.