1Health Sciences, University of Wisconsin, Milwaukee, Milwaukee, Wisconsin
ACell Biology, Neurobiology and Anatomy, BOphthalmology, 2Medical College of Wisconsin, Milwaukee, Wisconsin
Commercial Relationships: Sandeep Gopalakrishnan, None; Betsy Abroe, None; Heather Schmitt, None; Adam M. Dubis, None; Phyllis Summerfelt, None; Joseph Carroll, None; Janis T. Eells, None
Support: JTE: FFB TA-NP-0709-0465-UWI, International Retinal Research Foundation. JC: NIH (EY017607, EY001931, EY014537), MCW Research Affairs Committee, RBP Career Development Award.
Purpose:Irradiation by light in the far-red to NIR region of the spectrum (photobiomodualtion, PBM) has been demonstrated to attenuate the severity of neurodegenerative disease in experimental and clinical studies. The purpose of this study was to test the hypothesis that a brief course of PBM would protect against the loss of retinal function and improve photoreceptor survival in a rodent model of retinitis pigmentosa.
Methods:P23H-1 pups were treated once per day for 180 seconds with 830 nm light (25 mW/cm2; fluence 4 J/cm2) using a light-emitting diode array (Quantum Devices, Barneveld WI) from postnatal day p10 to p25. Sham-treated rats were restrained for 180 seconds, but not exposed to NIR light. The status of the retina was determined at p30 by measuring indices of photoreceptor function by ERG (scotopic series from 100mcd.s/m2 to 25000mcd.s/m2) and retinal morphology by Spectral Domain Optical Coherence Tomography (SD-OCT; Bioptigen, Inc).
Results:830 nm PBM protected against retinal degeneration in the P23H rat as assessed by ERG and SD-OCT. In NIR treated animals the a-wave amplitude at 1000 mcd.s/m2 was 117 ± 10 µV compared to 77 ± 7 µV in sham treated animals (p=0.007). The b-wave amplitude in NIR treated rats was 643 ± 49 µV compared to 415 ± 27 µV in sham treated animals (p=0.002). Total retinal thickness measured by SD-OCT linear scans was 179 ± 8 µm in NIR treated animals compared to 147± 8 µm for sham treated animals (p=0.04).
Conclusions:Studies from our laboratory have documented preservation of retinal function and attenuation of photoreceptor loss by PBM in animal models of mitochondrial injury and light-induced retinal degeneration. Results from this study demonstrate the retinoprotective effects of 830nm PBM in a transgenic animal model of retinitis pigmentosa and support the use of PBM as an innovative, non-invasive therapeutic approach for the treatment of retinal degenerative disease.
Keywords: retinal degenerations: hereditary photoreceptors mitochondria
© 2011, The Association for Research in Vision
and Ophthalmology, Inc., all rights reserved. Permission to republish any
abstract or part of an abstract in any form must be obtained in writing
from the ARVO Office prior to publication.