Toric intraocular lens outcomes with a new protocol for IOL selection and implantation

Abstract

The published literature on toric intraocular lenses (IOL) reports postoperative refractive cylinder less than or equal to 0.5 D in anywhere from 25% to 100% of implantations with both the Acrysof® Toric and Tecnis® Toric IOL, depending upon the article. However, the majority of articles tend to cite rates between 70% and 80%. The purpose was to evaluate my personal outcomes for both models of toric IOL, in terms of one-month postoperative refractive cylinder, after implementation of new methods of IOL selection, calculation and implantation. The new protocol included measurement of centroid surgically induced astigmatism by vector analysis; calculations using only the Barrett toric calculator, for which the keratometry values were obtained by optical biometry, while the keratometric axes were chosen by visual inspection of the axial topographic map; preoperative marking with the toriCAM cell phone appliance; and corneal incisions performed either manually or with a femtosecond laser. A prospective, observational study was conducted of all consecutive monofocal toric IOL implantations from September 2016 through April 2017. One-month postoperative refractive cylinder was recorded for each eye. Seventy eyes were implanted with monofocal toric IOL, 31 Acrysof® Toric and 39 Tecnis® Toric. Mean postoperative refractive cylinder was 0.48 D (0.00-1.50) for the Acrysof® Toric group and 0.46 D (0.00-1.00) for the Tecnis® Toric group. There were no statistically significant differences in postoperative refractive cylinder between IOL models or methods of incision. The percentage of eyes achieving postoperative refractive cylinder ≤0.50 D ("success") was 77% for the Acrysof® Toric group (82% for laser-assisted and 75% for manual) and 72% for the Tecnis® Toric group (80% for laser-assisted and 69% for manual). The implementation of the new protocol resulted in an overall surgical success rate of 77% for Acrysof® Toric IOL and 72% for Tecnis® Toric IOL (P=0.7702). Femtosecond laser-assisted surgery resulted in higher success rates than manual surgery (82% vs. 75% for Acrysof® Toric and 80% vs. 69% for Tecnis® Toric), but these differences were not statistically significant (Acrysof® Toric P=0.7336; Tecnis® Toric P=0.8862).