Multiple sclerosis (MS) involves an immune system attack against the central nervous system and causes progressive paralysis by destroying nerve cells and the spinal cord. It interrupts vision, balance, and even thinking. Although there is still no cure, there are some medications and alternative treatments that may help. Exploring another possible alternative treatment, exposure to a certain wavelength of light called near-infrared (NIR), are scientists at the University of Wisconsin-Milwaukee.

In rodent models, early MS-like symptoms were treated with exposure to NIR light for a week, alternating with a week of no light, and the clinical condition of the mice improved. Other experiments with blinded rats revealed that certain doses of NIR light allowed the lab animals to regain their sight.

Scientists have known for years that certain wavelengths of light in certain doses can heal, but they are only now uncovering exactly how phototherapy works. In applying NIR light therapy to MS, they have identified the right timing and dose. Furthermore, analyzing the effect the light had on the animal's genes revealed that molecules that would make the disease worse were weakened after exposure to light, and ones responsible for improvement were strengthened. They said that correctly dosed NIR light acts on the mitochondria and a particular enzyme, cytochrome C oxidase, to stimulate cell repair. NIR light heals by ensuring that cytochrome oxidase binds with oxygen to turn on protectors and stimulate cell metabolism.

Determining the best wavelength of light for phototherapy is a difficult task. Studies show that 670 nanometer (nm) and 830 nm light are beneficial, but 730 nm is not. The other difficult task is determining the appropriate dose and dose regimen for delivering the light.

The researchers explained that phototherapy holds the potential to improve other degenerative diseases, including cancer and even recalcitrant bedsores. Wounds treated with phototherapy healed two and a half times more quickly than untreated wounds.

Blue light, on the other hand, causes a toxic environment when the immune response has been triggered. That poisonous effect hastens healing of topical wounds by killing bacteria that cause infection.