Presbyopia, the age-related loss of the ability to accommodate, is the most common ocular affliction, affecting every human over the age of 45 years. Its pathophysiology is poorly understood. In the rhesus monkey, the only known animal model for the human condition, the ciliary muscle loses its configuration response to cholinomimetic drugs or central stimulation with age. Although some evidence suggests that this loss of mobility may be due to restriction by a progressively inelastic posterior attachment, it is not clear that the muscle's contractile machinery continues to function normally, nor what roles the lens, lens capsule and zonule might play. This project will determine, by digital image analysis of Scheimpflug, goniographic and infrared photorefractive video recordings in living surgically aniridic rhesus monkeys encompassing the entire species lifespan: ( 1 ) the real-time dynamics of ciliary muscle, lenticular and zonular movement in response to midbrain stimulation; (2) the effect of extra- and intra-capsular lens extraction, posterior capsulotomy and complete posterior capsulectomy following extracapsular lens extraction, and anterior and posterior regional zonulolysis on these real-time dynamics; (3) correlations of these interactions with age; (4) the role of choroidal/ciliary muscle elasticity in the development of presbyopia (by severing or scarifying the posterior attachment of the ciliary muscle). These studies will generate new information about the pathophysiology of presbyopia.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
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Visual Sciences A Study Section (VISA)
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Liberman, Ellen S
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University of Wisconsin Madison
Schools of Medicine
United States
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Croft, Mary Ann; Heatley, Gregg; McDonald, Jared P et al. (2016) Accommodative movements of the lens/capsule and the strand that extends between the posterior vitreous zonule insertion zone & the lens equator, in relation to the vitreous face and aging. Ophthalmic Physiol Opt 36:21-32
Flügel-Koch, Cassandra M; Croft, Mary Ann; Kaufman, Paul L et al. (2016) Anteriorly located zonular fibres as a tool for fine regulation in accommodation. Ophthalmic Physiol Opt 36:13-20
Croft, Mary Ann; McDonald, Jared P; Katz, Alexander et al. (2013) Extralenticular and lenticular aspects of accommodation and presbyopia in human versus monkey eyes. Invest Ophthalmol Vis Sci 54:5035-48
Croft, Mary Ann; Nork, T Michael; McDonald, Jared P et al. (2013) Accommodative movements of the vitreous membrane, choroid, and sclera in young and presbyopic human and nonhuman primate eyes. Invest Ophthalmol Vis Sci 54:5049-58
Lütjen-Drecoll, Elke; Kaufman, Paul L; Wasielewski, Rainer et al. (2010) Morphology and accommodative function of the vitreous zonule in human and monkey eyes. Invest Ophthalmol Vis Sci 51:1554-64
Croft, Mary Ann; McDonald, Jared P; Nadkarni, Nivedita V et al. (2009) Age-related changes in centripetal ciliary body movement relative to centripetal lens movement in monkeys. Exp Eye Res 89:824-32
Wendt, Mark; Croft, Mary Ann; McDonald, Jared et al. (2008) Lens diameter and thickness as a function of age and pharmacologically stimulated accommodation in rhesus monkeys. Exp Eye Res 86:746-52
Wasilewski, Rainer; McDonald, Jared P; Heatley, Gregg et al. (2008) Surgical intervention and accommodative responses, II: forward ciliary body accommodative movement is facilitated by zonular attachments to the lens capsule. Invest Ophthalmol Vis Sci 49:5495-502
Croft, Mary Ann; McDonald, Jared P; James, Rebecca J et al. (2008) Surgical intervention and accommodative responses, I: centripetal ciliary body, capsule, and lens movements in rhesus monkeys of various ages. Invest Ophthalmol Vis Sci 49:5484-94
Croft, Mary Ann; Glasser, Adrian; Heatley, Gregg et al. (2006) The zonula, lens, and circumlental space in the normal iridectomized rhesus monkey eye. Invest Ophthalmol Vis Sci 47:1087-95

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