Interchangeability of bilateral anterior chamber depth in intraocular lens power calculation and its application in unilateral lens subluxation

Abstract

Aims/Purpose: To assess the interchangeability of bilateral anterior chamber depth (ACD) in intraocular lens (IOL) power calculation, and to evaluate whether using the unaffected fellow eye's ACD can enhance refractive results in unilateral lens subluxation.Methods: Axial length (AL), keratometry (K) and ACD were obtained by IOLMaster 700. In cataract surgery candidates (Group 1), the virtual implantation of the same IOL model was used. The predictive results closest to the Plano of the Kane formula, using the right eye's biometry (AL, K and ACD), served as a benchmark. The results of the corresponding IOL power were further calculated by substituting the left eye's ACD for the right eye's one and compared with the benchmark. Eyes with unilateral lens subluxation (Group 2) underwent in‐the‐bag IOL placement after the capsular hook(s) implantation, with refraction conducted at least 1 month post‐operatively. Prediction errors (PE) of the Kane formula with or without the unaffected fellow eye's ACD were compared.Results: 392 eyes of 196 patients were analysed, including 173 candidates and 23 patients with unilateral subluxated lenses. In Group 1, there was no significant difference in bilateral ACD (p = 0.30). The predictive refraction using the right eye's ACD was −0.16 ± 0.10 diopter (D), and that obtained by the left eye's one was −0.16 ± 0.11 D (p = 0.64), with an absolute difference of 0.03 ± 0.03 D. In Group 2, the ACD was 2.89 ± 0.86 mm of the affected eye and 3.14 ± 0.37 mm of the fellow eye (p = 0.17). The median absolute PE, mean absolute PE and the percentage of PEs within ±0.50 D using the affected eye's ACD were 0.50 D, 0.59 D and 52.17%. Using the unaffected eye's ACD improved the outcomes to 0.45D, 0.52 D and 60.87%.Conclusions: Bilateral ACD values are interchangeable in routine IOL power calculation, and using the unaffected fellow eye's ACD can improve its accuracy in cases of unilateral lens subluxation undergoing in‐the‐bag IOL implantation.