Effect of anterior chamber depth on the accuracy of different intraocular lens rsquo; formulas

• Published in: BioMedica Vol. 38; no. 3; pp. 143 - 148
• Main Authors: Muhammad Moin, Tayyaba Gul Malik, Rabail Alam
• Format: Journal Article
• Language: English
• Published: Discover STM Publishing Ltd 01.09.2022
• DOI: 10.51441/BioMedica/5-751

Background and Objectives: Due to the difference in anterior segments among different races, intraocular lens formulas behave differently. Asian eyes have smaller anterior segment dimensions than Caucasian eyes. This study was carried out to evaluate the effect of different values of anterior chamber depth on the accuracy of Sanders, Retzlaff, Kraff/Theoretical (SRK/T), Hill Radial Basis Function (Hill RBF 2), and Barrett Universal II (Barrett U II) formulas. Methods: This was a descriptive observational study. Ninety-six eyes of patients, who underwent phacoemulsification with intraocular lens implantation and ended uneventfully, were included. The patients were divided into two groups based on the anterior chamber depth (ACD). Group 1 had ACD > 3 mm and group 2 had ACD < 3 mm. Intraocular lens (IOL) power with SRK/T was calculated with a built-in formula in IOL Master 500. Barrett Universal II and Hill RBF 2 formulas were calculated using online calculators. Descriptive statistics were calculated for both groups. An independent t-test was applied for group comparison. Results: Comparisons of the mean prediction errors of groups 1 and 2 using three different formulas were not statistically significant (p > 0.05). However, SRK/T had the lowest median prediction error for both groups but the highest percentage of eyes within ±0.5 D of absolute prediction error (APE) for group 1 and the lowest percentage of eyes within ±0.5 D of APE for group 2. Conclusion: There was no statistically significant effect of different anterior chamber depths on the accuracy of SRK/T, Barrett U II, and Hill RBF 2. The three formulas behaved similarly with different depths of the anterior chamber.