A recent study found changes in blood flow in the retina could explain why some migraine patients experience visual symptoms. The findings could represent a long-sought observable marker for migraines that physicians can use to aid in the clinical treatment of the condition, according to University of California, Los Angeles (UCLA) Health researchers who led the study.

While patients with migraines often experience symptoms such as pain around the eye, sensitivity to light, blind spots, and visual blurring, the mechanisms behind those symptoms have not been well understood. UCLA Health researchers used a non-invasive imaging technique, known as optical CT angiography, or OCTA, to visualize changes in the retinal blood vessels of migraine patients both during and between migraine attacks. The imaging was performed on 37 migraine patients with aura symptoms, 30 migraine patients without aura symptoms, and 20 healthy patients for a control group.

Researchers found that blood flow decreases in the retina during migraine attacks for both migraine patients with and without aura symptoms. However, patients with aura symptoms were found to have lower blood flow in certain areas of the retina compared to patients without aura symptoms. Additionally, asymmetrical blood flow in the retinas was also correlated with which side of the head that migraine patients experienced pain.

The findings could indicate why some patients experience visual symptoms and may represent a biomarker for migraine attacks, UCLA Health researchers say.