Comparative Accuracy of Barrett Toric Calculator With and Without Posterior Corneal Astigmatism Measurements and the Kane Toric Formula

To compare the accuracy of the Barrett toric calculator with and without posterior corneal astigmatism and the Kane toric calculator. Retrospective cross-sectional study. The study included a total of 79 eyes of 79 patients who underwent toric intraocular lens (IOL) insertion during uncomplicated cataract surgery by a single surgeon. Using vector analysis, the mean absolute prediction error, the standard deviation of the prediction error, and the percentage of eyes with a prediction error within ±0.50 diopter (D), ± 0.75 D, and ± 1.00 D were calculated. The IOL Master 700 (Carl Zeiss Meditec AG, Jena, Germany) was used for measuring biometry including posterior corneal astigmatism. The main analysis was designed to provide the clinical outcomes with each formula using the postoperative keratometry values and the measured postoperative IOL axis. Real-world analysis was performed using the preoperative keratometry values and the intended IOL axis. There was no significant difference in mean absolute prediction errors calculated with 2 versions of the Barrett toric formula (predicted posterior corneal astigmatism and measured posterior corneal astigmatism) and the Kane toric formula (P > .05). The Barrett toric calculator with predicted and measured posterior corneal astigmatism yielded the best results, with 60.8%