Indian Journal of Clinical and Experimental Ophthalmology 2022;8(4):549–554 Content available at: https://www.ipinnovative.com/open-access-journals Indian Journal of Clinical and Experimental Ophthalmology Journal homepage: www.ijceo.org Original Research Article Study of accuracy of biometric measurements in relation to intra ocular lens power calculation Prashansa Yadav 1, *, S. K. Prabhakar 1 , Feba Mary 1 1 Dept. of Ophthalmology, JSS Academy of Higher Education and Research, Mysuru, Karnataka, India ARTICLE INFO Article history: Received 27-09-2022 Accepted 01-11-2022 Available online 29-12-2022 Keywords: ACD ( Anterior Chamber Depth) IOLP (Intra ocular lens power) Kh (Horizontal meridian of cornea) Kv (Vertical meridian of cornea) ABSTRACT Introduction: Preoperative eye biometric measurements are critical for calculating IOL power, so it is essential to grasp how the various biometric parameters interact. The aim of this study is to determine the predictability and influence of biometric values on power calculation. Aim: To determine the relationship between IOL power and biometric values. Materials and Methods: It is an observational cross-sectional study done at a tertiary care center in Mysore, Karnataka. 110 eyes undergoing cataract surgeries were evaluated in the study over a period of four months. Preoperative biometry was performed and IOL power was calculated by SRK–II and A-scan. Pearson correlation coefficient matrix was tabulated. Model was obtained using multiple linear regression analysis. The comparison was made among all 6 models using the R square value and the standard error of the estimate. Results: Ka had a positive correlation with the Kh (r=0.955) and Kv(r=0.963), which had a weak negative correlation with AL (r =-0.358). Model 2 (SRK II-IOLP= (-0.900)*Ka + (-2.500)*AL+118.200) had the highest R square with no error, indicating the highest predictability in estimating IOLP. Estimating IOLP using an A-scan was a significant predictor but had the highest error with an R Square value of 0.206.Model 1 (A-scan- IOLP=(-0.191) *Ka +(-1.002)*AL+52.445) was the second most successful model. Ka can provide better predictability with both the methods to calculate the IOLP and AL. Conclusion: There is a limited evidence in comparing both the formulas. The SRK-II IOLP measurement showed higher accuracy using Ka and AL with no error in refractive error. A scan provided precise biometry data and IOL power calculation within an average range of ALs. The SRK- II formula’s predictability is higher than the A-scan formula. This is an Open Access (OA) journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms. For reprints contact: reprint@ipinnovative.com 1. Introduction Successful cataract surgery is determined by the final refractive outcome and patient’s satisfaction. It is crucial to calculate preoperative intraocular lens (IOL) power to achieve the required refractive outcome. 1 Biometry is important, which includes axial length (AL), keratometry (K) values and anterior chamber depth (ACD) to calculate IOL power. 2,3 Optical biometry provides several * Corresponding author. E-mail address: prashansa.yadav.26@gmail.com (P. Yadav). advantages, such as it is a fast and easy-to-use technique. Compared to ultrasonography, optical biometry provides reduced risk of trauma and infection, increased patient comfort and improved accuracy and repeatability of measurements. 4 To obtain optimum outcomes, an accurate IOL power formula should be used. 5 The variability in parameters used in the formula can lead to significant refractive errors postoperatively, requiring the use of glasses which would negate the sole purpose of cataract surgery. 5 Both SRK-II and A-scan can be used to calculate the IOLP. However, https://doi.org/10.18231/j.ijceo.2022.111 2395-1443/© 2022 Innovative Publication, All rights reserved. 549