Document Detail


The reduction of retinal autofluorescence caused by light exposure.
MedLine Citation:
PMID:  19628734     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: A prior study showed that long exposure to 568-nm light at levels below the maximum permissible exposure safety limit produces retinal damage preceded by a transient reduction in the autofluorescence of retinal pigment epithelial (RPE) cells in vivo. The present study shows how the effects of exposure power and duration combine to produce this autofluorescence reduction and find the minimum exposure causing a detectable autofluorescence reduction.
METHODS: Macaque retinas were imaged using a fluorescence adaptive optics scanning laser ophthalmoscope to resolve individual RPE cells in vivo. The retina was exposed to 568-nm light over a square subtending 0.5 degrees with energies ranging from 1 to 788 J/cm(2), where power and duration were independently varied.
RESULTS: In vivo exposures of 5 J/cm(2) and higher caused an immediate decrease in autofluorescence followed by either full autofluorescence recovery (exposures <or= 210 J/cm(2)) or permanent RPE cell damage (exposures >or= 247 J/cm(2)). No significant autofluorescence reduction was observed for exposures of 2 J/cm(2) and lower. Reciprocity of exposure power and duration held for the exposures tested, implying that the total energy delivered to the retina, rather than its distribution in time, determines the amount of autofluorescence reduction.
CONCLUSIONS: That reciprocity held is consistent with a photochemical origin, which may or may not cause retinal degeneration. The implementation of safe methods for delivering light to the retina requires a better understanding of the mechanism causing autofluorescence reduction. Finally, RPE imaging was demonstrated using light levels that do not cause a detectable reduction in autofluorescence.
Authors:
Jessica I W Morgan; Jennifer J Hunter; William H Merigan; David R Williams
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2009-07-23
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  50     ISSN:  1552-5783     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  2009 Dec 
Date Detail:
Created Date:  2009-12-03     Completed Date:  2009-12-23     Revised Date:  2014-09-15    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  6015-22     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Female
Fluorescence*
Light / adverse effects*
Lipofuscin / metabolism*
Macaca fascicularis
Macaca mulatta
Macaca nemestrina
Male
Ophthalmoscopy / methods
Radiation Dosage
Radiation Injuries, Experimental / etiology,  metabolism*
Retina / radiation effects*
Retinal Degeneration / etiology,  metabolism*
Retinal Pigment Epithelium / metabolism*
Time Factors
Grant Support
ID/Acronym/Agency:
EY01319/EY/NEI NIH HHS; EY014375/EY/NEI NIH HHS; EY07125/EY/NEI NIH HHS; R01 EY004367/EY/NEI NIH HHS; R01 EY004367-24/EY/NEI NIH HHS
Chemical
Reg. No./Substance:
0/Lipofuscin
Comments/Corrections

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