Accidental ingestion of methanol, a common ingredient in antifreeze and windshield wiper fluid, can cause blindness within two days. Researchers believe that formic acid, a product of methanol metabolism, robs a victim of sight by attacking the mitochondria of cells in the retina and optic nerve. Now the results of a rat study published online this week by the Proceedings of the National Academy of Sciences suggest that shining red light on affected eyes may stave off methanol's blinding effects.

Janis T. Eells and her colleagues at the Medical College of Wisconsin exposed both control rats and animals that had ingested methanol to a red light-emitting diode (LED) in a process known as photobiomodulation. Just three brief irradiation treatments promoted the recovery of retinal function and prevented damage to photoreceptor cells in the poisoned animals, the team found. The light caused no damage to the eyes of the control rats. The results build on previous work indicating that light in the far-red to near-infrared spectral range can help wounds heal more quickly and stimulate growth in cultured cells.

Because mitochondrial dysfunction is thought to play a role in a variety of eye diseases, including macular degeneration and glaucoma, the scientists posit that photobiomodulation with red light could represent a novel therapy for these conditions. Diseases that attack the human retina are much more complex than the animal model used in the current study, however, so more research will be needed to determine if this approach can help more people see the light.