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° ± 1.13° at 1 to 3 days, 1.58° ± 1.36° at 30 days, and 1.83°
± 1.44° at 90 to 180 days. No lens rotated more than 5°. 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.