Do you suffer from migraines?
If you do, you are part of the 15% of the
with migraine. You will also know that migraines are debilitating – attacks can happen spontaneously and typically involve a throbbing headache, nausea and/or vomiting, and sensitivity to light and sound. You might also have experienced sensory disturbances, particularly visual disturbances with your attacks, such as blurred vision or a visual aura (e.g. bright zig zag patterns or a blindspot appearing in your vision).
We have been interested in testing people while they are not having a migraine (called the interictal period) and over the years, we have found that migraine sufferers do not always perform normally on certain visual tests even though they are asymptomatic and apparently normal. For example, when we test how sensitive people are to lights appearing in their side vision (visual field tests), people with migraine can show areas of reduced sensitivity. When we place electrodes on a person’s scalp over the visual part of the brain and record electrical signals (electrophysiology tests), the responses are not as strong in people with migraine. Some studies also find subtle thinning of the retina near the optic nerve head in migraine sufferers using advanced imaging techniques.
3D optic nerve head imaging using a confocal scanning laser ophthalmoscope
While we don’t know exactly why these visual abnormalities occur, their presence creates a problem for eyecare clinicians and researchers. Visual field, electrophysiology and imaging tests are conducted as part of an eye examination to diagnose and manage patients with glaucoma, which is a progressive disease that affects the optic nerve and can eventually lead to blindness. Some studies also suggest that migraine may increase the risk of glaucoma, so it’s important to be able to differentiate between these two conditions.
Bao, one of our research fellow, recently published a review paper in Progress in Retinal and Eye Research titled ‘Clinical impact of migraine for the management of glaucoma patients’ that collates evidence from many studies of migraine to date, and provides some practical suggestions for managing patients who come in for glaucoma testing but who also happen to suffer from migraines.