The objectives of the proposed research are to 1) more narrowly define homogeneous subgroups of retinitis pigmentosa (RP), 2) characterize the natural course of the spread of retinal degeneration in RP, and 3) describe the pathophysiology of visual function loss in RP. We propose to perform over a period of five years annual follow-up measures of 1) visual fields, 2) electroretinogram intensity-response and flicker-phase functions, 3) static two-color perimetric absolute thresholds, 4) rhodopsin density, photosensitivity, and regeneration kinetics by densitometry, and 5) focal psychophysical thresholds in relation to fundus features using our stimulator fundus camera. These results will enable us to characterize the nature of the spread of retinal degeneration. To characterize the pathophysiology of visual function loss we propose perimetric measures of flash-on-flash increment thresholds on different steady backgrounds and at different times in relation to the onset and offset of the background. These results will yield information about photoreceptor neural adaptation mechanisms in RP. Subgroupings of RP will be more narrowly defined based on cross-comparisons of natural history and visual function data. We will extend our segregation analyses to test various genetic hypotheses for the different functional subgroups of RP.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY001791-13
Application #
3256207
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1979-07-01
Project End
1990-06-30
Budget Start
1988-07-01
Budget End
1989-06-30
Support Year
13
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
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