Near-Infrared Photobiomodulation in Retinal Injury and Disease.
1Department of Biomedical Sciences, University of Wisconsin-Milwaukee, 2400 E. Hartford Ave., 53201, Milwaukee, WI, USA. email@example.com.
2College of Nursing, University of Wisconsin-Milwaukee, 53201, Milwaukee, WI, USA. firstname.lastname@example.org.
3Divsion of Biomedical Sciences, Research School of Biology, Australian National University, 0200, Acton, Australia. email@example.com.
Photobiomodulation Mitigates Diabetes-Induced Retinopathy by Direct and Indirect Mechanisms: Evidence from Intervention Studies in Pigmented Mice.
1Case Western Reserve University, Cleveland, Ohio, United States of America; Catholic University of Brasilia, Brasilia, Brazil.
2Case Western Reserve University, Cleveland, Ohio, United States of America.
3Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America.
4Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America; Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States of America.
5Case Western Reserve University, Cleveland, Ohio, United States of America; Cleveland Veteran’s Affairs Medical Center, Research Service 151, Cleveland, Ohio, United States of America.
Daily application of far-red light from the onset of diabetes mitigated diabetes-induced abnormalities in retinas of albino rats. Here, we test the hypothesis that photobiomodulation (PBM) is effective in diabetic, pigmented mice, even when delayed until weeks after onset of diabetes. Direct and indirect effects of PBM on the retina also were studied.
Diabetes was induced in C57Bl/6J mice using streptozotocin. Some diabetics were exposed to PBM therapy (4 min/day; 670 nm) daily. In one study, mice were diabetic for 4 weeks before initiation of PBM for an additional 10 weeks. Retinal oxidative stress, inflammation, and retinal function were measured. In some mice, heads were covered with a lead shield during PBM to prevent direct illumination of the eye, or animals were treated with an inhibitor of heme oxygenase-1. In a second study, PBM was initiated immediately after onset of diabetes, and administered daily for 2 months. These mice were examined using manganese-enhanced MRI to assess effects of PBM on transretinal calcium channel function in vivo.
PBM intervention improved diabetes-induced changes in superoxide generation, leukostasis, expression of ICAM-1, and visual performance. PBM acted in part remotely from the retina because the beneficial effects were achieved even with the head shielded from the light therapy, and because leukocyte-mediated cytotoxicity of retinal endothelial cells was less in diabetics treated with PBM. SnPP+PBM significantly reduced iNOS expression compared to PBM alone, but significantly exacerbated leukostasis. In study 2, PBM largely mitigated diabetes-induced retinal calcium channel dysfunction in all retinal layers.
PBM induces retinal protection against abnormalities induced by diabetes in pigmented animals, and even as an intervention. Beneficial effects on the retina likely are mediated by both direct and indirect mechanisms. PBM is a novel non-pharmacologic treatment strategy to inhibit early changes of diabetic retinopathy.
Low-intensity far-red light inhibits early lesions that contribute to diabetic retinopathy: in vivo and in vitro.
Case Western Reserve University, Cleveland, OH 44106, USA.
Treatment with light in the far-red to near-infrared region of the spectrum (photobiomodulation [PBM]) has beneficial effects in tissue injury. We investigated the therapeutic efficacy of 670-nm PBM in rodent and cultured cell models of diabetic retinopathy.
Studies were conducted in streptozotocin-induced diabetic rats and in cultured retinal cells. Diabetes-induced retinal abnormalities were assessed functionally, biochemically, and histologically in vivo and in vitro.
We observed beneficial effects of PBM on the neural and vascular elements of retina. Daily 670-nm PBM treatment (6 J/cm(2)) resulted in significant inhibition in the diabetes-induced death of retinal ganglion cells, as well as a 50% improvement of the ERG amplitude (photopic b wave responses) (both P < 0.01). To explore the mechanism for these beneficial effects, we examined physiologic and molecular changes related to cell survival, oxidative stress, and inflammation. PBM did not alter cytochrome oxidase activity in the retina or in cultured retinal cells. PBM inhibited diabetes-induced superoxide production and preserved MnSOD expression in vivo. Diabetes significantly increased both leukostasis and expression of ICAM-1, and PBM essentially prevented both of these abnormalities. In cultured retinal cells, 30-mM glucose exposure increased superoxide production, inflammatory biomarker expression, and cell death. PBM inhibited all of these abnormalities.
PBM ameliorated lesions of diabetic retinopathy in vivo and reduced oxidative stress and cell death in vitro. PBM has been documented to have minimal risk. PBM is noninvasive, inexpensive, and easy to administer. We conclude that PBM is a simple adjunct therapy to attenuate the development of diabetic retinopathy.
Mitochondrion. 2004 Sep;4(5-6):559-67.
Mitochondrial signal transduction in accelerated wound and retinal healing by near-infrared light therapy.
Eells JT, Wong-Riley MT, VerHoeve J, Henry M, Buchman EV, Kane MP, Gould LJ, Das R, Jett M, Hodgson BD, Margolis D, Whelan HT.
Department of Health Sciences, College of Health Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA. firstname.lastname@example.org
Photobiomodulation by light in the red to near infrared range (630-1000 nm) using low energy lasers or light-emitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury in the heart and attenuate degeneration in the injured optic nerve. Recent evidence indicates that the therapeutic effects of red to near infrared light result, in part, from intracellular signaling mechanisms triggered by the interaction of NIR light with the mitochondrial photoacceptor molecule cytochrome c oxidase. We have demonstrated that NIR-LED photo-irradiation increases the production of cytochrome oxidase in cultured primary neurons and reverses the reduction of cytochrome oxidase activity produced by metabolic inhibitors. We have also shown that NIR-LED treatment prevents the development of oral mucositis in pediatric bone marrow transplant patients. Photobiomodulation improves wound healing in genetically diabetic mice by upregulating genes important in the promotion of wound healing. More recent studies have provided evidence for the therapeutic benefit of NIR-LED treatment in the survival and functional recovery of the retina and optic nerve in vivo after acute injury by the mitochondrial toxin, formic acid generated in the course of methanol intoxication. Gene discovery studies conducted using microarray technology documented a significant upregulation of gene expression in pathways involved in mitochondrial energy production and antioxidant cellular protection. These findings provide a link between the actions of red to near infrared light on mitochondrial oxidative metabolism in vitro and cell injury in vivo. Based on these findings and the strong evidence that mitochondrial dysfunction is involved in the pathogenesis of numerous diseases processes, we propose that NIR-LED photobiomodulation represents an innovative and non-invasive therapeutic approach for the treatment of tissue injury and disease processes in which mitochondrial dysfunction is postulated to play a role including diabetic retinopathy, age-related macular degeneration, Leber’s hereditary optic neuropathy and Parkinson’s disease.
|Vestn Oftalmol. 2001 Sep-Oct;117(5):11-4.|
Comparative effectiveness of different methods of quantum hemotherapy in the treatment of juvenile diabetic retinopathy
[Article in Russian]
Effects of ultraviolet exposure of the blood (UVEB), intravenous laser exposure of the blood (IVLEB), and transcutaneous magnetic laser exposure of the blood (TMLEB) on ocular functions, microcirculation, and hemodynamics were studied in 79 patients with juvenile diabetic retinopathy. All these treatments had a nonspecific positive effect on the spatial contrast sensitivity, microcirculation, and choroid hemodynamics of the eye. Correcting mainly intravascular changes in the microcirculatory bed, quantum hemotherapy methods are pathogenetically justified in the treatment and prevention of tissue ischemia in diabetic involvement of the organ of vision. Results of noninvasive TMLEB with generalized and local effects were statistically similar to results of invasive UVEB and IVLEB.