Comparative evaluation of surgical correction of corneal astigmatism by toric IOL implantation using various keratometric data and calculation methods

Abstract

Purpose. Compare the effectiveness of regular corneal astigmatism correction with toric monofocal IOL using various keratometric data and calculation methods. Material and methods. The study included 28 patients (31 eyes) with age-related cataracts and regular corneal astigmatism who underwent phacoemulsification (n=31) with implantation of a monofocal toric IOL (EnVista Toric). Two groups were formed according to the type of calculation and possible options of keratometric data: 1) keratometric data of IOL-master 500 + online manufacturer's calculator; 2) keratometric data of the anterior and posterior corneal surfaces (Pentacam HR) + Barrett's toric calculator. Results. The mean absolute deviation of the predicted residual astigmatism from the actual one was distributed as follows: 1st group – 0.62±0.62 D, 2nd group – 0.41 ± 0.71 D. The values of the mean absolute vector and mean centroid error in diopters were: 0.80±0.59 D and 0.06 D in 1st group, 0.48±0.65 D and 0.02 D in 2nd group, respectively. Conclusion. When using the measured astigmatism of the anterior and posterior surface of the cornea, Barrett's toric calculator showed the best result. The most accurate forecast of residual astigmatism was obtained using the Barrett calculator in combination with Pentacam keratometry data (Axial\Sagittal (Front), Axial\Sagittal (Back)). Key words: corneal astigmatism, posterior corneal astigmatism, toric IOL, centroid analysis, keratometry, cataract surgery