Representative image for migraine.
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New Delhi: Changes in blood flow in the retina of the eye could explain why some migraine patients experience visual symptoms, a study has found.
The retina is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some mollusks.
The findings, published in the journal Headache: The Journal of Head and Face Pain, could represent a long-sought observable marker for migraines that doctors can use to aid in the clinical treatment of the condition.
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.
Researchers from the University of California, Los Angeles in the US used a non-invasive imaging technique, known as optical coherence tomography angiography, or OCTA, to visualise 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.
The 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, fhe researchers said.
Additionally, asymmetrical blood flow in the retinas was also correlated with which side of the head that migraine patients experienced pain, they said.
The findings could indicate why some patients experience visual symptoms and may represent a biomarker for migraine attacks, according to the researchers.