Comparison of Ultrasound and Lenstar Biometry Methods in Determining Axial Length and Refractive Error after Cataract Surgery

Ocular biometry refers to the measurement of the axial length of the eye and thickness of the intraocular structures. This process is routinely performed for all patients before cataract surgery. The accuracy of the biometric data is directly associated with the refractive status after cataract surgery. Currently, two methods of biometry, namely ultrasound and optical biometry, are used to calculate the intraocular lens power. The purpose of this study was to compare the Lenstar and ultrasound biometry methods in determining the axis length and refractive error after cataract surgery. This descriptive cross-sectional study was conducted on 372 patients with cataract. The study population was randomly divided into two groups of Lenstar and ultrasound based on the biometry methods they received. A total of 17 patients were excluded from the study due to having mature and dense cataract. Therefore, the study was continued with 355 patients, 186 and 169 cases of whom were managed with ultrasound and Lenstar biometry methods, respectively. Postoperative refractive errors were evaluated in each patient 4-6 weeks after the surgery. The two groups were compared in terms of the mean absolute refractive error using paired sample t-test. The mean absolute refractive errors before the surgery were obtained as 2.38±3.93 and 2.19±2.68 diopter in the ultrasound and Lenstar groups, respectively, which were not significantly different between the two groups (P=0.2). The mean axial lengths of the eye were 23.10±1.19 and 23.34±1.17 mm in the ultrasound and Lenstar groups, respectively. The two groups showed no significant difference in this regard (P=0.96). After the operation, the mean absolute refractive errors in the ultrasound and Lenstar groups were 0.56±0.45 and 0.51±0.38 diopter, respectively. This variable was not significantly different between the two groups after the surgery (P=0.11). The findings of this study revealed no significant difference between the ultrasound and Lenstar biometry methods in terms of determining the axis length and mean absolute refractive error after cataract surgery.