Clinical Results Of The Barrett Toric Intraocular Lens Formula Using Posterior Corneal Astigmatism Measurements

To compare the accuracy of the Barrett toric calculator using predicted posterior astigmatism and posterior astigmatism measurements using a swept-source optical coherence tomography (SS-OCT) and Scheimpflug camera, respectively.

Seoul St.Mary's Hospital, Seoul, Korea

A total of 163 eyes of 163 patients who underwent uncomplicated cataract surgery by a single surgeon were studied. Using vector analysis, the mean absolute prediction error, the standard deviation of prediction error, percentage of eyes with a prediction error within ±0.50 diopters (D), ±0.75D, and ±1.00D were calculated. Biometric measurements, including posterior astigmatism, were performed using a SS-OCT (IOL Master 700®; Carl Zeiss Meditec AG, Jena, Germany) and a Scheimpflug camera (Pentacam HR®, Oculus, Wetzlar, Germany). The main analysis analyzed the clinical results for each formula using the postoperative keratometry and the measured postoperative intraocular lens axis.

The centroid of prediction error for the Barrett toric calculator with measured posterior astigmatism using a SS-OCT was only not statistically significant from 0. The mean absolute prediction error of the Barrett formula using measured posterior astigmatism utilizing a SS-OCT and Scheimpflug camera, and posterior astigmatism prediction value was 0.39, 0.36, and 0.38 D, respectively. The prediction error within ±0.50D was 71.2, 73.6, and 73.6%, and there was no statistically significant difference between the three versions of the formula.

The Barrett toric calculator with measured posterior astigmatism using a SS-OCT showed the most accurate postoperative refractive astigmatism prediction error, and all three versions of the Barrett formula showed excellent accuracy.