Comparison of toric IOL astigmatism predictions derived from IOLMaster 700 and iTrace keratometry

We compared toric intraocular lens planning predictions derived from the IOLMaster 700 (IOLM) and iTrace and evaluated differences in their postoperative astigmatism predictions after cataract surgery. This single-center prospective observational study included patients undergoing uncomplicated toric IOL implantation. The implanted lens was selected using IOLM-based calculations, while iTrace measurements generated a simulated alternative prediction. Prediction errors were assessed using vector analysis. A total of 216 eyes from 165 patients were included. Mean absolute prediction error was 0.47 ± 0.33 D for the IOLM and 0.49 ± 0.34 D for the iTrace. Prediction-error centroids for IOLM were 0.35 D at 91° in the with-the-rule (WTR) subgroup, 0.30 D at 2° in the against-the-rule (ATR) subgroup, and 0.22 D at 143° in the Oblique subgroup. The corresponding values for iTrace showed no significant difference to those from IOLM in either vector component. The devices recommended the same cylinder power in 56.94% of eyes and were within one step in 95.83%. Mean absolute prediction errors were similar in the WTR and ATR subgroups. The IOLM produced the highest proportion of eyes with an absolute prediction error of ≤ 0.50 D, reaching 62.9% in the overall cohort and 70.7% in the ATR subgroup. The IOLM and iTrace produced different toric planning predictions in 43.06% of eyes, however 95.83% of eyes were within one power difference. The IOLM produced a higher proportion of eyes with an absolute prediction error ≤ 0.50 D, but this finding should be interpreted cautiously because only the IOLM-recommended lens was implanted.