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Biomimetic accommodating intraocular lens

Citation

DeBoer, Charles Meno Theodore (2012) Biomimetic accommodating intraocular lens. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z9B56GQH. http://resolver.caltech.edu/CaltechTHESIS:06042012-135440197

Abstract

The crystalline lens allows the eye to focus on near and far objects. During the aging process, it loses its ability to focus and often becomes cloudy during cataract formation. At this point, traditional medical therapy replaces the lens with an artificial replacement lens. Although replacement lenses for the crystalline lens have been implanted since 1949 for cataract surgery, none of the FDA-approved lenses mimic the anatomy of the natural lens. Hence, they are not able to focus in a manner similar to the youthful lens. Instead, they function in a manner similar to the aged lens and only provide vision at a single distance or at a very limited range of focal distances. Patients with the newest implants are often obliged to use reading glasses when using near vision, or suffer from optical aberrations, halos, or glare. Therefore, there is a need to provide youthful vision after lens surgery in terms of focusing ability, accurate optical power, and sharp focus without distortion or optical aberrations.

This thesis presents an approach to restoring youthful vision after lens replacement. An intraocular lens (IOL) that can provide accurate visual acuity along with focusing ability is proposed. This IOL relies on the natural anatomy and physiology of the eye, and therefore is actuated in a manner identical to the natural lens. In addition, the lens has the capability for adjustment during or after implantation to provide high-acuity vision throughout life.

The natural anatomy and physiology of the eye is described, along with lens replacement surgery. A lens design is proposed to address the unmet need of lens-replacement patients. Specific care in the design is made for small surgical incisions, high visual acuity, adjustable acuity over years, and the ability to focus similar to the natural lens. Methods to test the IOL using human donor tissue are developed based upon prior experiments on the ex vivo natural lens. These tools are used to demonstrate efficacy of the newly developed accommodating intraocular lens.

To further demonstrate implant feasibility, materials and processes for building the lens are evaluated for biocompatibility, endurance, repeatable manufacture, and stability. The lens biomechanics are determined after developing an artificial anatomy testing setup inspired by the natural anatomy of the human focusing mechanism. Finally, based upon a mechanical and optical knowledge of the lens, several improved lens concepts are proposed and demonstrated for efficacy.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Intraocular Lens, Accommodating, IOL, MEMS, microelectromechanical systems, biomedical, implant, ophthalmology
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Tai, Yu-Chong
Thesis Committee:
  • Tai, Yu-Chong (chair)
  • Humayun, Mark
  • Choo, Hyuck
  • Yang, Changhuei
  • Emami-Neyestanak, Azita
Defense Date:30 May 2012
Non-Caltech Author Email:charlesdeboer (AT) gmail.com
Funders:
Funding AgencyGrant Number
1Co, Inc.UNSPECIFIED
Projects:2011 SURF project by Hyung Wan Do: "Test Setup to Measure Properties of the Crystalline Lens"
Record Number:CaltechTHESIS:06042012-135440197
Persistent URL:http://resolver.caltech.edu/CaltechTHESIS:06042012-135440197
DOI:10.7907/Z9B56GQH
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7130
Collection:CaltechTHESIS
Deposited By: Charles DeBoer
Deposited On:17 Jun 2016 22:57
Last Modified:22 Aug 2016 21:11

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