Dynamic performance of accommodating intraocular lenses in a negative feedback control system: a simulation-based study.
A dynamic model of ocular accommodation is used to simulate the stability and dynamic performance of accommodating intraocular lenses (A-IOLs) that replace the hardened natural ocular lens that is unable to change focus. Accommodation simulations of an older eye with A-IOL materials having biomechanical properties of a younger eye illustrate overshoots and oscillations resulting from decreased visco-elasticity of the A-IOL. Stable dynamics of an A-IOL are restored by adaptation of phasic and tonic neural-control properties of accommodation. Simulations indicate that neural control must be recalibrated to avoid unstable dynamic accommodation with A-IOLs. An interactive web-model of A-IOL illustrating these properties is available at http://schorlab.berkeley.edu.
Schor
Clifton M
CM
Vision Science group, School of Optometry, University of California at Berkeley, Berkeley, CA 94720-2020, USA. schor@socrates.berkeley.edu
Bharadwaj
Shrikant R
SR
Burns
Christopher D
CD
D000065:Accommodation, Ocular / Q000502:physiology*; D000375:Aging / Q000502:physiology; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D004548:Elasticity; D005246:Feedback; D006801:Humans; D007910:Lenses, Intraocular; D008954:Models, Biological; D008959:Models, Neurological; D011305:Presbyopia / Q000503:physiopathology