What Triggers an Ocular Migraine?

Harsh lighting, long screen time, other visual strain, stress, dehydration, food additives, and other causes all may trigger an ocular migraine, a subtype that focuses in the eye and causes vision changes.

An ocular migraine refers to subtypes of migraine that are characterized by vision changes such as vision loss, blind spots, zig-zag lines, flashes of light, or seeing stars. 

Unlike other types of migraine, an ocular migraine may or may not occur with head pain. 

The term ocular migraine may also be used to refer to a retinal migraine, which is a form of migraine in which visual disturbances occur in just one eye before the headache phase of a migraine attack.

Symptoms of ocular migraine include vision disturbances in one or both eyes such as:

• “Aura” around objects
• Blind spots, especially in the central part of the visual field
• Bright lines 
• Flickering lights
• Flashes of light
• Zig-zag lines
• Seeing stars or patterns
• Other minor sight issues 

Ocular migraines may or may not be accompanied by head pain. 

The cause of ocular migraines is unknown but migraine auras are believed to result from abnormal electrical activity involving the outer surface (cortex) of the brain. 

Risk factors for migraines may include: 

• Genetics
• Hormones

Triggers for ocular migraine include: 

• Visual triggers
• Fluorescent or other harsh lighting 
• Extensive time spent staring at a screen
• Driving long distances 
• Taxing visual activities 
• Certain food products and food additives 
• Monosodium glutamate (MSG)
• Processed meat containing nitrates
• Aged or smoked cheese
• Onions
• Pickled products
• Avocados
• Dairy products
• Nuts
• Chocolate
• Caffeine
• Alcoholic beverages (in particular, red wine)
• Stress
• Dehydration
• High altitude
• Low blood sugar

Ocular migraine is diagnosed with a patient history, physical examination, and other tests such as: 

• Eye screening test
  • Direct examination
    • Patient sits in a chair in a room with the lights out
    • A doctor looks through the lenses of the ophthalmoscope to examine the eyes
    • Patient may be asked to look in various directions during the examination 
  • Indirect examination
    • Patient lies down or is seated in a reclined position
    • A doctor can see structures at the back of the eye in a little more detail with this method
    • The lens of the ophthalmoscope is held directly in front of the eye 
    • Patient may be asked to look in various directions during the examination 
    • A small, blunt probe may be used to apply a little pressure to the eye
  • Slit lamp examination
    • A slit lamp provides greater magnification of the back of the eye than an indirect exam
    • Drops may be administered to dilate the pupils 
    • The slit lamp positioned across from the patient who rest their chin and forehead on the instrument
    • A bright light is shined directly into the eye and a microscope is used to evaluate the back of the eye
• Other tests
  • Computerized tomography (CT) scan
  • Magnetic resonance imaging (MRI) scan
  • Blood tests
  • Spinal tap (also called a lumbar puncture)

Treatment for ocular migraine includes: 

• Medications
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) for pain
  • Anti-nausea medications
  • Calcium channel blockers
  • Antiepileptics 
  • Tricyclic antidepressants
• Lifestyle modifications
  • Don’t smoke
  • Avoid use of oral contraceptives or hormone replacement therapy
  • Rest your eyes
  • Get out of bright sunlight or other harsh lighting
  • Take breaks from looking at screens
  • Avoid triggers 
    • Visual triggers
    • Food products and food additives 
    • Stress
    • Dehydration
    • High altitude
    • Low blood sugar
    • Excessive heat