Presbyopia, the age related loss of accommodation, affects everyone by about age 50. The impact of presbyopia on society is considerable from an economic and a quality of life standpoint. Although presbyopia is classically attributed to sclerosis of the lens, the precise causes remain unclear. Studies on humans and monkeys show age changes in both the crystalline lens and the extralenticular accommodative apparatus. No widely accepted cures or preventions for presbyopia currently exist, although the possibility of restoring accommodation using surgical procedures or intraocular accommodative lenses is under investigation. This application proposes 1) using central stimulation of the Edinger-Westphal (EW) nucleus of the brain in rhesus monkeys together with dynamic analyses to better understand how the young monkey eye undergoes accommodative optical changes, 2) to use in vitro mechanical stretching of monkey lenses to study the accommodative optical changes and to understand if these are similar to those that occur in vivo with natural accommodation and 3) to determine if and how the dynamic and accommodative optical performance of the monkey eye changes with age as rhesus monkeys develop presbyopia. Two experimental approaches will be used; 1) accommodative optical and geometric changes in the lens will be measured dynamically during EW stimulated accommodation in anesthetized monkeys. The dynamic accommodative responses will be compared in """"""""young"""""""" and """"""""middle-aged"""""""" monkeys. 2) In vitro mechanical stretching experiments will be performed on partially dissected enucleated monkey eyes to artificially induce accommodative changes in the lens. The mechanically induced optical and geometric changes will be compared with those that occur during accommodation in vivo and as a function of age. The results will quantify the dynamic accommodative responses in monkey eyes to understand the dynamics of accommodation, will allow a determination of the differences and similarities in the accommodative changes between in vitro mechanical stretching and in vivo accommodation of the lens and on how the accommodative performance of the monkey lens changes with age. The goal of this research is to gain a better understanding of how the monkey lens undergoes physical and optical accommodative changes and contribute to the progression of presbyopia. This research will provide a foundation for studies directed at understanding if accommodation can be restored with artificial accommodative intraocular lenses.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
1R01EY014651-01
Application #
6601403
Study Section
Special Emphasis Panel (ZRG1-VISA (01))
Program Officer
Liberman, Ellen S
Project Start
2003-05-01
Project End
2007-04-30
Budget Start
2003-05-01
Budget End
2004-04-30
Support Year
1
Fiscal Year
2003
Total Cost
$334,125
Indirect Cost
Name
University of Houston
Department
Type
Schools of Optometry/Ophthalmol
DUNS #
036837920
City
Houston
State
TX
Country
United States
Zip Code
77204
Wendt, Mark; Glasser, Adrian (2010) Topical and intravenous pilocarpine stimulated accommodation in anesthetized rhesus monkeys. Exp Eye Res 90:605-16
Baumeister, Martin; Wendt, Mark; Glasser, Adrian (2010) Influence of amplitude, starting point, and age on first- and second-order dynamics of Edinger-Westphal-stimulated accommodation in rhesus monkeys. Invest Ophthalmol Vis Sci 51:5378-90
Ostrin, Lisa A; Glasser, Adrian (2010) Autonomic drugs and the accommodative system in rhesus monkeys. Exp Eye Res 90:104-12
Ghosn, Mohamad G; Sudheendran, Narendran; Wendt, Mark et al. (2010) Monitoring of glucose permeability in monkey skin in vivo using Optical Coherence Tomography. J Biophotonics 3:25-33
Bossong, Heather; Swann, Michelle; Glasser, Adrian et al. (2009) Applicability of infrared photorefraction for measurement of accommodation in awake-behaving normal and strabismic monkeys. Invest Ophthalmol Vis Sci 50:966-73
Baumeister, Martin; Wendt, Mark; Glasser, Adrian (2008) Edinger--Westphal stimulated accommodative dynamics in anesthetized, middle-aged rhesus monkeys. Exp Eye Res 86:25-33
Rosales, Patricia; Wendt, Mark; Marcos, Susana et al. (2008) Changes in crystalline lens radii of curvature and lens tilt and decentration during dynamic accommodation in rhesus monkeys. J Vis 8:18.1-12
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
Ostrin, Lisa A; Glasser, Adrian (2007) Effects of pharmacologically manipulated amplitude and starting point on edinger-westphal-stimulated accommodative dynamics in rhesus monkeys. Invest Ophthalmol Vis Sci 48:313-20
Win-Hall, Dorothy M; Ostrin, Lisa A; Kasthurirangan, Sanjeev et al. (2007) Objective accommodation measurement with the Grand Seiko and Hartinger coincidence refractometer. Optom Vis Sci 84:879-87

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