A Study on Comparison of Axial Length and IOL Power in A-Scan Biometry versus IOL Master

Author(s): B. L. Sujatha Rathod1 , Divya N. Raj2 , Bharathi Narasimhamurthy3 , Vidyadevi M.4 , Ranjitha Chowkahally Sadananda5 , Anupriya A.6

BACKGROUND Cataract is the leading cause of preventable blindness in the world. Accurate biometry is an essential component in determining the visual outcome after cataract surgery. With the introduction of newer instruments, various studies have been conducted regarding the accuracy of axial length and IOL power measurements. The aim of our study is to compare axial length (AXL) and IOL power values in A-scan biometry versus IOL master. METHODS A cross-sectional study was performed on 100 eyes in 100 patients presenting to clinical practice for cataract surgery with no retinal pathology in a tertiary eye care centre. Keratometry values were obtained from Auto ref-keratometer and the values were kept constant for both methods. Axial length was measured with Biomedix applanation ultrasound A-scan biometry and the Zeiss-700 IOL-Master. IOL power was calculated using SRK/T formula from the obtained values. Both values were compared between A-scan biometry and IOL-master. RESULTS Out of 100 patients, 67 were females and 33 were males. Mean age of the patients was 62.74 ± 7.92. The mean K1 and K2 were 44.30D and 44.90D respectively. The mean AXL measured by A-scan was 23.34 ± 0.72 mm and that with IOL master was 23.20 ± 0.65 mm. There was no statistically significant difference between two methods (p=0.1). The mean IOL power was 20.15 ± 4.84D with Ascan versus 20.85 ± 4.75D with IOL-master and the difference between the two methods was not statistically significant (p=0.2). CONCLUSIONS There is no significant difference in axial length and IOL power values when measured in A-scan biometry and IOL master. Both methods give accurate results and can be chosen accordingly.