Cone-Driven Retinal Pathways Involved in Migraine Photophobia Pathophysiology
Blue wavelengths of light invoked the most responses from thalamic neurons.
HealthDay News - Migraine photophobia appears to be induced, at least in part, by specific light wavelengths processed by cone driven retinal pathways, according to a study published online in the journal Brain. Using electroretinography and visual evoked potential recordings, researchers showed that light wavelengths corresponding to green activated cone-drive retinal pathways to a lesser extent than other wavelengths.
Rami Burstein, PhD, of the Beth Israel Deaconess Medical Center in Boston, and colleagues exposed 69 migraine patients to different colors of light. In addition, multi-unit recordings from dura- and light-sensitive thalamic neurons in rats were also recorded.
The researchers found that while blue light exacerbated headache pain, a narrow spectrum of low-intensity green light significantly reduced photophobia. In some cases, this green light also reduced migraine pain by about 20%.
"Although photophobia is not usually as incapacitating as headache pain itself, the inability to endure light can be disabling," Burstein said in a medical center news release.
"More than 80% of migraine attacks are associated with and exacerbated by light sensitivity, leading many migraine sufferers to seek the comfort of darkness and isolate themselves from work, family, and everyday activities."
1. Noseda R, Bernstein CA, Rony-Reuven Nir RR, et al. Migraine photophobia originating in cone-driven retinal pathways. Brain, 2016 DOI:10.1093/brain/aww119