Abstract
Purpose: :
To compare the long-term rotational stability of a one-piece dual haptic spherical intraocular lens (AcrySof SA60AT - Alcon Fort Worth Texas) with a one-piece four closed-loop haptic spherical intraocular lens (Akreos Adapt - Bausch & Lomb Rochester NY).
Methods: :
A post-hoc retrospective analysis was undertaken assessing retro-illumination images taken in a contra-lateral eye study of PCO. Features of the IOL visible in the dilated images were identified and compared over a period of from 3 months to 24 months. Rotational stability was then assessed by comparing the angular rotation of lenses over the study period
Results: :
The total number of evaluable images was 30 at 6 months and 44 at 12 and 24 months for the Akreos lens and 27 at 6 months, 32 at 12 months and 42 at 24 months for the Acrysof lens. Mean (SD) absolute rotation for the Akreos lens was 2.53 (±2.40) at 6 months, 2.57 (±2.28) at 12 months and 3.20 (±2.57) at 24 months. For Acrysof the mean (SD) absolute rotation was 2.67 (±2.22) at 6 months, 3.66 (±3.00) at 12 months and 3.33 (±3.06) at 24 months. The differences between the lenses were not significant at any time point.
Conclusions: :
As expected, the long term rotational stability of lenses is generally good. However the study does show that lenses can continue to rotate even after it is assumed that capsular bag contraction is complete and in the case of the AcrySof lens, rotational stability defined in the current draft of the ANSI standard, was not achieved during the study assessment period. Early rotational stability, prior to six months, will be assessed in another study but it should be noted that the performance of toric intraocular lenses may vary due to the different thickness profiles between steep and flat meridian.
Keywords: intraocular lens