COMPARISON OF THE ACCURACY OF TORIC INTRAOCULAR LENS FORMULAS USING PREDICTED AND MEASURED POSTERIOR CORNEAL ASTIGMATISM WITH OPTICAL LOW-COHERENCE REFLECTOMETRY AND SCHEIMPFLUG IMAGING

This study aims to compare the clinical outcomes of the Barrett toric intraocular lens (IOL) formula when using predicted posterior corneal astigmatism versus outcomes obtained by substituting measured posterior corneal astigmatism from a Scheimpflug camera.

Department of Ophthalmology, Eunpyeong St. Mary's Hospital, The Catholic University of Korea

Twenty eyes that underwent uncomplicated toric IOL cataract surgery by a single surgeon were included. Vector analysis was applied to calculate the mean absolute prediction error, standard deviation of the prediction error, and the proportion of eyes within ±0.50D, ±0.75D, and ±1.00D of the prediction error. Biometric measurements were taken with an optical low-coherence biometer (Lenstar LS900®; Haag-Streit, Bern, Switzerland), and posterior corneal curvature was measured with a Scheimpflug camera (Pentacam HR®; Oculus, Wetzlar, Germany). The main analysis focused on postoperative corneal curvature and the actual measured IOL axis to evaluate clinical outcomes for each formula.

No statistically significant difference was observed in the mean absolute prediction error between the two versions of the Barrett toric IOL formula—one using measured posterior corneal astigmatism and the other using predicted values. The average centroid value was 0.12D @ 97° ± 0.54D for the predicted astigmatism formula and 0.16D @ 93° ± 0.57D for the measured values formula, with no significant difference from zero (P > 0.05).

The Barrett toric IOL formula demonstrated excellent clinical outcomes, regardless of whether it used predicted or measured posterior corneal astigmatism from a Scheimpflug camera, based on optical low-coherence biometry.