Assessing postoperative toric intraocular lens rotation: comparative analysis

Abstract

Purpose: To investigate the accuracy of 3 distinct postoperative toric intraocular lens (TIOL) rotational stability measurement methods.

Setting: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.

Design: Single-center, prospective, interventional clinical trial.

Methods: 128 eyes of 81 patients with age-related cataract received a hydrophobic acrylic TIOL Clareon CNW0T3-9. To evaluate rotational stability, 3 distinct assessment methods were used: (Rotix) comparing the TIOL axis at the end of surgery (EoS) with 1 week and 6 months postoperatively using reference vessels at the sclera, (Slitlamp) comparing the intended axis (IA) with the axis at 1 week and 6 months using slitlamp photography using the horizontal axis as a reference, and (Casia) comparing the IA with the axis at 1 week and 6 months using the axis determination tool of a swept-source anterior segment optical coherence tomographer (Casia 2).

Results: Mean absolute rotation from EoS/IA to 6 months differed significantly among Rotix (1.33 ± 1.99 degrees [0.01; 19.80]), Casia (2.88 ± 2.64 degrees [0.00; 19.00]), and Slit-lamp (4.38 ± 3.38 degrees [0.02; 19.38]), as indicated by the Friedman test (χ 2 = 71.852, P < .001). Bland-Altman coefficients of repeatability (CoRs) indicated the closest agreement of results between Casia and Rotix, with a CoR of ±3.95 degrees, followed by Slit-lamp and Casia (±6.82 degrees), and finally, between Slit-lamp and Rotix (±7.19 degrees).

Conclusions: When assessing true TIOL rotational stability, it is imperative to use fixed anatomical landmarks as a reference and establish a baseline at the EoS. When assessing TIOL rotation along the horizontal axis, considering cyclorotation of the eye is crucial and must not be underestimated.