Synchrony dual-optic accommodating intraocular lens: Part 1: Optical and biomechanical principles and design considerations
Accepted 4 September 2006.
Purpose
To describe a dual-optic accommodating intraocular lens (IOL) based on theoretical considerations.
Setting
University and independent research group.
Methods
Ray-tracing analysis using optical modeling software (ZEMAXTM, Focus Software Inc., Tucson, Ariz) in a theoretical model eye was used to analyze lens configurations to optimize the accommodative and magnification effects of axial lens displacement. Finite-element modelling using a commercially available PC-based software package (COSMOS DesignSTAR) was applied to design the biomechanical parameters of the inter-optic articulations and optics.
Results
Ray-tracing analysis indicated that a dual-optic design with a high plus-powered front optic coupled to a minus posterior optic produced greater change in conjugation power of the eye compared to a single-optic intraocular lens and that magnification effects were unlikely to account for improved near vision. Finite-element modelling indicated that the 2 optics can be linked by spring-loaded haptics that allow anterior and posterior axial displacement of the front optic in response to changes in ciliary body tone and capsular tension.
Conclusion
A dual-optic design linked by spring haptics increases the accommodative effect of axial optic displacement with minimal magnification effect and has promise for improving the performance of accommodative intraocular lenses.
From the Department of Ophthalmology, University of California San Francisco (McLeod), San Francisco, Visiogen Inc. (Vargas, Ting), Irvine, and a private consultant (Portney), Tustin, California, USA
Corresponding author: Stephen D. McLeod, MD, University of California San Francisco, Department of Ophthalmology, 10 Koret Way, K-304, San Francisco, California 94143, USA.
Supported in part by unrestricted grants from That Man May See, San Francisco, California, and Research to Prevent Blindness, New York, New York, USA
Drs. McLeod, Vargas, Portney, and Ting have a financial interest in Visiogen Inc. and in the intraocular lens described.
ABSTRACT