Evaluation of porcine crystalline lenses in comparison with molded polymer gel lenses with an improved ex vivo accommodation simulator

The ex vivo accommodation simulator stretches crystallin e lenses radially under controlled conditions, while monitoring the changes in zonular tension and lens di ameter. A dual coaxial laser beam system was added for measuring changes in optical power as the lens is stretched. The EVAS instrument was fully characterized and calibrated. The results from 3 porcine eyes will be presented. Several crystalline lenses, similar in shape and size to porcine lenses, were cast molded in silic one gels of different stiffness. These lenses were evaluated using the EVAS instrument and custom made lens holding fixtures. With their well defined shape and material properties, results from these measurements will be useful for cross-validation of finite element models.

[1]  Jean-Marie A Parel,et al.  Ex vivo accommodation simulator II: concept and preliminary results , 2004, SPIE BiOS.

[2]  F. Manns,et al.  Dioptric Power vs Zonular Tension During Ex-vivo Simulated Accommodation of Primate Crystaline Lenses Before and After Refilling , 2003 .

[3]  F. Manns,et al.  Method For Ex-vivo Assessment Of Accommodation Forces , 2002 .

[4]  J. Parel,et al.  Accommodation Stress-Strain Relation in Human and Non-Human Primate Eyes Ex-Vivo , 2002 .

[5]  O. Nishi,et al.  Capsule opacification after refilling the capsule with an inflatable endocapsular balloon , 1997, Journal of cataract and refractive surgery.

[6]  David A. Atchison,et al.  Continuous gradient index and shell models of the human lens , 1995, Vision Research.

[7]  J. Parel,et al.  Accommodation of an endocapsular silicone lens (Phaco-Ersatz) in the aging rhesus monkey. , 1994, Journal of refractive and corneal surgery.

[8]  D A Atchison,et al.  Modeling the power of the aging human eye. , 1992, Journal of the Optical Society of America. A, Optics and image science.

[9]  E W Norton,et al.  Accommodation of an endocapsular silicone lens (Phaco-Ersatz) in the nonhuman primate. , 1987, Ophthalmology.

[10]  J. Parel,et al.  Phaco-Ersatz: Cataract surgery designed to preserve accommodation , 1986, Graefe's Archive for Clinical and Experimental Ophthalmology.

[11]  J KESSLER,et al.  EXPERIMENTS IN REFILLING THE LENS. , 1964, Archives of ophthalmology.

[12]  Aart C Kooijman,et al.  Polymer refilling of presbyopic human lenses in vitro restores the ability to undergo accommodative changes. , 2003, Investigative ophthalmology & visual science.