Predictive accuracy of an intraoperative aberrometry device for a new monofocal intraocular lens

Abstract

Purpose: To evaluate refractive outcomes for the Clareon monofocal intraocular lens (IOL) in terms of achieved target refraction for the ORA (ALCON) intraoperative wavefront aberrometry device and preoperative noncontact biometry.

Setting: University Eye Clinic Maastricht, Maastricht University Medical Center+, the Netherlands.

Design: Prospective observational clinical trial.

Methods: Patients with bilateral age-related cataracts undergoing phacoemulsification, either by delayed sequential surgery or on the same day, were included in the study. Exclusion criteria were an increased risk for refractive surprise or complicated surgery. Implanted IOL power was based on noncontact optical biometry data using the Barrett Universal II (BU-II) formula, optimized for the Clareon IOL. Postoperative subjective refraction was measured 4 to 6 weeks after surgery. Catquest-9SF questionnaires were completed preoperatively and 3 months after surgery.

Results: 100 eyes (51 patients) were included. The percentages of eyes within 1.0 diopters (D), 0.75 D, 0.50 D, and 0.25 D of target for ORA vs BU-II were 84% (84 eyes), 72% (72 eyes), 57% (57 eyes), and 21% (21 eyes) vs 97% (97 eyes), 88% (88 eyes), 77% (77 eyes), and 53% (53 eyes), respectively. Mean absolute prediction error was significantly higher for ORA vs preoperative biometry (P < .001). After global optimization, the prediction accuracy of ORA improved significantly (P < .001). Catquest-9SF questionnaires showed improved levels of ability at 3 months after surgery (P < .001).

Conclusions: This study showed lower percentages of eyes within target refraction for ORA (prior to lens constant optimization) compared with the BU-II formula when implanting the Clareon IOL. However, prediction accuracy of ORA improved significantly after global optimization. Therefore, further intraoperative measurements, postoperative measurements, and optimization are needed to improve the ORA prediction for this IOL.

Figure 1.

One-month results of the percentage of eyes with an achieved spherical equivalent refraction within 1.0 D, 0.75 D, 0.50 D, and 0.25 D of target for the Barrett Universal II formula vs ORA-recommended power (both prior and after optimization) for the Clareon monofocal IOL.

Figure 2.

One-month results of the percentage of eyes with an achieved spherical equivalent refraction within 1.0 D, 0.75 D, 0.50 D, and 0.25 D of target for ORA prior to global optimization vs after global optimization.

Figure 3.

Double-angle vector plot of preoperative keratometric astigmatism (measured by the IOLM700), intraoperative astigmatism, and the manifest postoperative refractive astigmatism after implantation with the Clareon monofocal IOL.

Figure 4.

Double-angle vector plot of the astigmatism difference (SIA) between preoperative keratometric and postoperative manifest refraction (A) and intraoperative ORA and postoperative manifest refraction (B). SIA = surgically induced astigmatism.