670nm photobiomodulation as a novel protection against retinopathy of prematurity: evidence from oxygen induced retinopathy models

• Published in: PloS one 2013-08, Vol.8 (8), p.e72135
• Main Authors: Natoli, Riccardo, Valter, Krisztina, Barbosa, Marconi, Dahlstrom, Jane, Rutar, Matt, Kent, Alison, Provis, Jan
• Format: Article
• Language: English
• Subjects: Abnormalities; Analysis; Animal models; Animals; Birth weight; Blood vessels; Cell death; Cytochrome; Edema; Exposure; Hemorrhage; Histochemistry; Histopathology; Hyperoxia; Light levels; Light therapy; Lung - pathology; Lung - radiation effects; Lung diseases; Lung Diseases - complications; Lung Diseases - pathology; Lung Diseases - prevention & control; Medical research; Medical schools; Medical treatment; Metabolism; Mice; Mice, Inbred C57BL; Neovascularization; Neovascularization, Pathologic - chemically induced; Neovascularization, Pathologic - complications; Neovascularization, Pathologic - pathology; Neovascularization, Pathologic - prevention & control; Organs; Oxygen; Oxygen - adverse effects; Pathogenesis; Phototherapy - methods; Preventive medicine; Rats; Rats, Sprague-Dawley; Retina; Retina - pathology; Retina - radiation effects; Retinal Vessels - pathology; Retinal Vessels - radiation effects; Retinopathy; Retinopathy of prematurity; Retinopathy of Prematurity - chemically induced; Retinopathy of Prematurity - complications; Retinopathy of Prematurity - pathology; Retinopathy of Prematurity - prevention & control; Science
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0072135

To investigate the validity of using 670nm red light as a preventative treatment for Retinopathy of Prematurity in two animal models of oxygen-induced retinopathy (OIR). During and post exposure to hyperoxia, C57BL/6J mice or Sprague-Dawley rats were exposed to 670 nm light for 3 minutes a day (9J/cm²). Whole mounted retinas were investigated for evidence of vascular abnormalities, while sections of neural retina were used to quantify levels of cell death using the TUNEL technique. Organs were removed, weighed and independent histopathology examination performed. 670 nm light reduced neovascularisation, vaso-obliteration and abnormal peripheral branching patterns of retinal vessels in OIR. The neural retina was also protected against OIR by 670 nm light exposure. OIR-exposed animals had severe lung pathology, including haemorrhage and oedema, that was significantly reduced in 670 nm+OIR light-exposed animals. There were no significance differences in the organ weights of animals in the 670 nm light-exposed animals, and no adverse effects of exposure to 670 nm light were detected. Low levels of exposure to 670 nm light protects against OIR and lung damage associated with exposure to high levels of oxygen, and may prove to be a non-invasive and inexpensive preventative treatment for ROP and chronic lung disease associated with prematurity.