There is increasing concern that exposure to ultraviolet light, found in solar radiation, may be involved in the etiology of ocular disorders such as age-related macular degeneration. There is, however, an incomplete understanding of the mechanisms by which light stress leads to retinal pathology. The proposed research will investigate the role of near- ultraviolet light in causing retinal degeneration and aging. Recent findings in our laboratory have established pigmented rats as a suitable experimental animal for studying near-ultraviolet light toxicity of the retina. Using primarily the rat model and in some cases rabbits, experiments are specifically designed to 2) characterize near-ultraviolet light retinal damage in sub-primate mammals and distinguish it from the well-known form of retinal damage in these species that is caused by green light (i.e. rhodopsin-mediated damage); 2) evaluate the role of various endogenous chromophores in mediating or influencing near-ultraviolet retinal damage; 3) examine the possible involvement of lipid peroxidation in the biochemical etiology of near-UV retinal toxicity; 4) examine the influence of near-ultraviolet light stress on retinal aging; and 5) evaluate the relative contribution of different visible wavelength bands in causing retinal lesions produced by operating microscope light. A quantitative, multidisciplinary approach will be applied to these studies using electroretinographic, morphometric and various biochemical techniques. The intention of the proposed studies is to provide an in-depth analysis of the mechanisms by which near-ultraviolet light leads to retinal pathology. The information obtained from these studies could help to predict the conditions predisposing the retinal to near-ultraviolet damage and to devise strategies for preventing and managing photically-induced retinal disease.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY004554-08
Application #
3258980
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1983-03-01
Project End
1995-03-31
Budget Start
1991-04-01
Budget End
1992-03-31
Support Year
8
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Rapp, L M; Maple, S S; Choi, J H (2000) Lutein and zeaxanthin concentrations in rod outer segment membranes from perifoveal and peripheral human retina. Invest Ophthalmol Vis Sci 41:1200-9
Rapp, L M; Ghalayini, A J (1999) Influence of UVA light stress on photoreceptor cell metabolism: decreased rates of rhodopsin regeneration and opsin synthesis. Exp Eye Res 68:757-64
Rakoczy, P E; Lai, M C; Vijayasekaran, S et al. (1996) Initiation of impaired outer segment degradation in vivo using an antisense oligonucleotide. Curr Eye Res 15:119-23
Rapp, L M; Fisher, P L; Suh, D W (1996) Evaluation of retinal susceptibility to light damage in pigmented rats supplemented with beta-carotene. Curr Eye Res 15:219-23
Pittler, S J; Fliesler, S J; Fisher, P L et al. (1995) In vivo requirement of protein prenylation for maintenance of retinal cytoarchitecture and photoreceptor structure. J Cell Biol 130:431-9
Rapp, L M; Fisher, P L; Dhindsa, H S (1994) Reduced rate of rod outer segment disk synthesis in photoreceptor cells recovering from UVA light damage. Invest Ophthalmol Vis Sci 35:3540-8
Rapp, L M; Fisher, P L; Sheinberg, C H (1994) Impact of lipofuscin on the retinal pigment epithelium: electroretinographic evaluation of a protease inhibition model. Graefes Arch Clin Exp Ophthalmol 232:232-7
Fliesler, S J; Florman, R; Rapp, L M et al. (1993) In vivo biosynthesis of cholesterol in the rat retina. FEBS Lett 335:234-8
Rapp, L M; Smith, S C (1992) Evidence against melanin as the mediator of retinal phototoxicity by short-wavelength light. Exp Eye Res 54:55-62
Rapp, L M; Smith, S C (1992) Morphologic comparisons between rhodopsin-mediated and short-wavelength classes of retinal light damage. Invest Ophthalmol Vis Sci 33:3367-77

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