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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
The John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia. riccardo.natoli@anu.edu.au
Riccardo
R
Natoli
Krisztina
K
Valter
Marconi
M
Barbosa
Jane
J
Dahlstrom
Matt
M
Rutar
Alison
A
Kent
Jan
J
Provis
D000818:Animals; D008168:Lung / Q000473:pathology / Q000528:radiation effects; D008171:Lung Diseases / Q000150:complications / Q000473:pathology / Q000517:prevention & control; D051379:Mice; D008810:Mice, Inbred C57BL; D009389:Neovascularization, Pathologic / Q000139:chemically induced / Q000150:complications / Q000473:pathology / Q000517:prevention & control*; D010100:Oxygen / Q000009:adverse effects*; D010789:Phototherapy / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000473:pathology* / Q000528:radiation effects; D012171:Retinal Vessels / Q000473:pathology* / Q000528:radiation effects; D012178:Retinopathy of Prematurity / Q000139:chemically induced / Q000150:complications / Q000473:pathology / Q000517:prevention & control*
D010100:Oxygen