Evaluating Rotational Stability of an Extended Depth of Focus Toric Intraocular Lens Using a Slit Lamp and Image-Based Analysis

Purpose: To evaluate the rotational stability of a toric extended depth of focus (EDOF) intraocular lens (IOL), using either slit lamp evaluation or image-processing software.

Setting: Three clinical practices in the USA.

Design: Prospective unmasked randomized clinical trial.

Methods: Subjects presenting for routine cataract surgery that were interested in improved near vision received toric EDOF lenses (TECNIS Symfony^® Toric) in both eyes. The measures of interest in the current analysis were the change in orientation of the IOL between 1 day, 1 month and 3 months postoperative. Orientation was measured at the microscope on the day of surgery, and with the slit lamp at all other visits. Day 1, 1-month and 3-month images of the lens orientation were captured with a slit lamp camera. Differences in orientation were recorded and analyzed.

Results: A total of 150 eyes had IOL orientation data available. Image analysis showed mean absolute lens orientation changes from 1 day to 1 month and 3 months of less than 2 degrees. The percentage of lenses exhibiting rotation of ≤5 degrees between any measured time points was 97% or higher. Results were similar, but significantly more variable, when IOL orientation was measured at the slit lamp.

Conclusion: The toric EDOF lens evaluated here demonstrated rotational stability that exceeded the prior ANSI standard. The best method to determine IOL orientation changes was through image analysis. .