Rotational Stability and Centration of a New Toric Lens Design Platform Using Objective Image Analysis Over 6 Months.

PURPOSE: To determine the rotational stability of the Rayner 600S intraocular lens (IOL) (Rayner, Worthing, United Kingdom) using objective image analysis techniques. METHODS: A total of 66 patients (mean age: 69.92 +/- 8.45 years) with healthy eyes presenting for routine cataract surgery were implanted monocularly with the 600S IOL and followed up over 90 to 180 days postoperatively. Images of the IOL were captured through a maximally dilated pupil (tropicamide 1.0%, phenylephrine 2.5%) immediately after surgery and after 1 to 3 days, 30 days, and 90 to 180 days using a digital slit-lamp biomicroscope. The orientation of the IOL markings were image analyzed compared to conjunctival blood vessel landmarks visible across all time points to correct for head and rotation. Centration was assessed by drawing ovals to circumscribe the IOL, pupil, and limbus to compare the centers (0.01 mm per-pixel resolution). RESULTS: Absolute values for rotation postoperatively were 1.60 degrees +/- 1.13 degrees at 1 to 3 days, 1.58 degrees +/- 1.36 degrees at 30 days, and 1.83 degrees +/- 1.44 degrees at 90 to 180 days. No lens rotated more than 5 degrees. The average centration relative to the limbus was -0.04 +/- 0.25 mm horizontally and 0.04 +/- 0.26 mm vertically at 1 to 3 days, 0.00 +/- 0.38 mm vertically and 0.01 +/- 0.28 mm horizontally at 30 days, and 0.08 +/- 0.37 mm vertically and 0.07 +/- 0.47 mm horizontally at 90 to 180 days. CONCLUSIONS: The Rayner 600S IOL showed exceptional rotational stability and centration after implantation, meeting the U.S. Food and Drug Administration prescribed American National Standards Institute standards for toric IOLs.