The proposed research seeks clarification of neural and/or biochemical mechanisms that control postnatal ocular growth and the development of myopia (nearsightedness) good experimental model, evidence of retinal participation in the regulatory process and discovery of clear neuropharmacological effects on eye growth make this a reasonable goal. In the chick, juvenile monkey and likely in man, a vision-dependent feedback mechanisms influences postnatal ocular growth, hence implicating neural mechanisms in control of eye size and refractive error. Our recent observations of elevated vasoactive intestinal peptide in the myopic monkey retina and depressed dopamine in the myopic chick retina constitute the first identifications of neurochemical alterations in experimental myopia. Our follow-up pharmacological studies demonstrate that local application of dopaminergic agents not only can prevent the axial elongation characteristic of myopia but also can modify its shape. Expanding these studies, we have found that cholinergic agents also influence the growth of the chick eye in the axial dimension. We seek a more detailed understanding of how these neurochemical and neuropharmacological observations can be integrated into an improved understanding of the mechanisms that regulate ocular growth and refractive status. Using the chick as a model, studies will be directed to the following areas: 1) Further definition of the role of dopamine in ocular growth control and the development of refractive errors. We shall seek further correlates of retinal dopamine with experimental conditions influencing eye growth and shall continue to study the influence of locally applied dopamine agents. 2) Clarification of cholinergic influences on eye growth. Besides expanding our pharmacological findings, we shall initiate biochemical and histochemical studies. 3) Identification of other mechanisms governing ocular growth and refractive error. In seeking other possible neural mechanisms, we shall emphasize the peripheral nervous system and neuropeptides. By coordinating pharmacological, biochemical, histochemical and anatomical methods, we seek to clarify mechanisms controlling ocular growth, emmetropization and the development of myopia. We hope that these studies ultimately will lead to an improved understanding of human myopia and to a viable drug therapy to prevent its development.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY007354-03
Application #
3264271
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1990-08-01
Project End
1995-07-31
Budget Start
1992-08-01
Budget End
1994-07-31
Support Year
3
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Brown, Jamin S; Flitcroft, D Ian; Ying, Gui-shuang et al. (2009) In vivo human choroidal thickness measurements: evidence for diurnal fluctuations. Invest Ophthalmol Vis Sci 50:5-12
Liu, Ji; McGlinn, Alice M; Fernandes, Alcides et al. (2009) Nicotinic acetylcholine receptor subunits in rhesus monkey retina. Invest Ophthalmol Vis Sci 50:1408-15
Stone, Richard A; Pendrak, Klara; Sugimoto, Reiko et al. (2006) Local patterns of image degradation differentially affect refraction and eye shape in chick. Curr Eye Res 31:91-105
Stone, Richard A; Wilson, Lorri B; Ying, Gui-Shuang et al. (2006) Associations between childhood refraction and parental smoking. Invest Ophthalmol Vis Sci 47:4277-87
Wilson, Lorri B; Quinn, Graham E; Ying, Gui-shuang et al. (2006) The relation of axial length and intraocular pressure fluctuations in human eyes. Invest Ophthalmol Vis Sci 47:1778-84
Stone, Richard A; Sugimoto, Reiko; Capehart, Cheryl et al. (2006) Anterior segment growth and peripheral neural pathways in chick. Curr Eye Res 31:511-7
Reigada, David; Lu, Wennan; Zhang, Xiulan et al. (2005) Degradation of extracellular ATP by the retinal pigment epithelium. Am J Physiol Cell Physiol 289:C617-24
Chong, Yap-Seng; Liang, Yu; Tan, Donald et al. (2005) Association between breastfeeding and likelihood of myopia in children. JAMA 293:3001-2
Saw, Seang-Mei; Tan, Say-Beng; Fung, Daniel et al. (2004) IQ and the association with myopia in children. Invest Ophthalmol Vis Sci 45:2943-8
Saw, S-M; Chia, K-S; Lindstrom, J M et al. (2004) Childhood myopia and parental smoking. Br J Ophthalmol 88:934-7

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