Assessing Astigmatic Prediction Errors: A Comparative Analysis Of The Barrett’S Toric And Tecnis Amo Toric Iol Calculators

To compare the predictive accuracy of the Barrett’s Toric and Tecnis AMO Toric IOL calculators in estimating residual astigmatism and spherical equivalent (SE) in eyes undergoing toric intraocular lens implantation.

Tertiary Eye care centre

Seventy-four eyes of 74 patients undergoing uneventful cataract surgery with Tecnis Toric IOL implantation were included. IOL power was calculated using either the Barrett’s Toric calculator or the Tecnis AMO Toric calculator. Primary outcome was the prediction error in residual astigmatism. Secondary outcomes included mean absolute error (MAE), centroid error, and prediction error in SE. Vector analysis was performed using standard double-angle plots. Statistical comparisons were made using t-tests, Mann-Whitney U tests, and chi-square tests where appropriate.

There was no statistically significant difference in residual astigmatism, centroid error, or MAE between the two calculators. However, the Barrett’s calculator demonstrated significantly better accuracy in predicting SE (p < 0.05). Both calculators performed similarly in predicting residual astigmatism across a homogenous sample in terms of biometric parameters.

While both calculators are effective for astigmatism correction, the Barrett’s Toric calculator may offer enhanced predictability in SE outcomes, especially in refractively demanding patients. This supports its use in precision-based IOL planning for toric lens implantation.