Synchrony dual-optic accommodating intraocular lens. Part 1: optical and biomechanical principles and design considerations.
OBJECTIVE
To describe a dual-optic accommodating intraocular lens (IOL) based on theoretical considerations.


METHODS
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.


CONCLUSIONS
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.
McLeod
Stephen D
SD
Department of Ophthalmology, University of California San Francisco, San Francisco, California, USA. mcleods@vision.ucsf.edu
Vargas
Luis G
LG
Portney
Val
V
Ting
Albert
A
D000065:Accommodation, Ocular / Q000502:physiology*; D001696:Biomechanical Phenomena; D002387:Cataract Extraction; D003198:Computer Simulation; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008433:Mathematics; D008962:Models, Theoretical; D055095:Optics and Photonics; D011474:Prosthesis Design; D012029:Refraction, Ocular / Q000502:physiology