In Vivo Imaging of Retinal Oxidative Stress Using a Reactive Oxygen Species-Activated Fluorescent Probe.
OBJECTIVE
In vivo methods for detecting oxidative stress in the eye would improve screening and monitoring of the leading causes of blindness: diabetic retinopathy, glaucoma, and age-related macular degeneration.


METHODS
To develop an in vivo biomarker for oxidative stress in the eye, we tested the efficacy of a reactive oxygen species (ROS)-activated, near-infrared hydrocyanine-800CW (H-800CW) fluorescent probe in light-induced retinal degeneration (LIRD) mouse models. After intravitreal delivery in LIRD rats, fluorescent microscopy was used to confirm that the oxidized H-800CW appeared in the same retinal layers as an established ROS marker (dichlorofluorescein).


RESULTS
Dose-response curves of increasing concentrations of intravenously injected H-800CW demonstrated linear increases in both intensity and total area of fundus hyperfluorescence in LIRD mice, as detected by scanning laser ophthalmoscopy. Fundus hyperfluorescence also correlated with the duration of light damage and functional deficits in vision after LIRD. In LIRD rats with intravitreal injections of H-800CW, fluorescent labeling was localized to photoreceptor inner segments, similar to dichlorofluorescein.


CONCLUSIONS
Hydrocyanine-800CW detects retinal ROS in vivo and shows potential as a novel biomarker for ROS levels in ophthalmic diseases.
Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.
Megan C
MC
Prunty
Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.
Moe H
MH
Aung
Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta, Georgia, United States.
Adam M
AM
Hanif
Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta, Georgia, United States.
Rachael S
RS
Allen
Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.
Micah A
MA
Chrenek
Department of Ophthalmology, Emory University, Atlanta, Georgia, United States 2Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta, Georgia, United States.
Jeffrey H
JH
Boatright
Biomedical Research, Atlanta VA Medical Center, Atlanta, Georgia, United States 4Department of Medicine, Emory University, Atlanta, Georgia, United States.
Peter M
PM
Thule
LI-COR, Lincoln, Nebraska, United States.
Kousik
K
Kundu
Department of Bioengineering, University of California, Berkeley, California, United States.
Niren
N
Murthy
Department of Ophthalmology, Emory University, Atlanta, Georgia, United States 2Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta, Georgia, United States.
Machelle T
MT
Pardue
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D009887:Ophthalmoscopy / Q000379:methods*; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012162:Retinal Degeneration / Q000378:metabolism*
D015415:Biomarkers; D005456:Fluorescent Dyes; D017382:Reactive Oxygen Species