Accuracy Of The Toric Calculators On The Escrs Calculator

Accuracy assessment of the toric intraocular lens power (IOL) calculators available at the European Society of Cataract and Refractive Surgeons (ESCRS) online calculator.

Studio Oculistico d’Azeglio, Bologna, Italy.

For patients undergoing cataract surgery with toric IOL implantation, pre-operative measurements with the IOLMaster 700 were collected. Keratometry (K), biometric measurements and patient gender were inserted in the ESCRS online calculator. A surgical induced astigmatism of 0.15 diopters (D) at 180° was considered. For each calculator the predicted refractive astigmatism and the recommended axis of implantation were recorded. Using the Eyetemis “Toric Prediction Adjustment” tool each calculator’s predicted refractive astigmatism was transformed from their axis to the real post-operative IOL orientation. Vector analysis was performed to obtain the prediction error (PE) for each of the four calculators.

The study included 174 eyes (108 right-eyes) of 174 patients (104 females). Mean pre-operative astigmatism was 1.41 ± 0.90 D. A PE of 0.13 D @ 82.3° was obtained for the Barrett Toric Calculator, 0.14 D @ 82.4° with the EVO Calculator, whereas 0.02 D @ 23.9° for the Hoffer QST, and 0.04 D @ 77.6° for the Kane Calculator. With the EVO calculator, 61.49% of eyes had a PE within 0.50 D, with the Barrett and Kane calculators 60.34% and with the Hoffer QST, 56.90%. No statistically significant difference was found (Kruskal-Wallis test, p-value = 0.665).

The online ESCRS calculator provides accurate results from four new generation calculators for toric IOL power calculations. Overall, the calculators’ predictions obtained considering the postoperative IOL orientation were comparable with percentages around 60% of eyes within 0.50D.