Migraine can be a very debilitating affliction which anyone who has ever suffered such a headache can attest to; some sufferers sadly succumb to these on a regular basis.
Ocular migraine headaches are characterised by visual disturbance in one or both eyes. Technically there are two subtypes of ocular migraine:
- Retinal migraine which has a visual disturbance in one eye
- Migraine with an aura which has a visual disturbance in both eyes
In the case of the subtype of retinal migraine, it is important that this is diagnosed correctly because if a patient presents with visual disturbance in one eye only it may be a symptom of something much more serious such as a detached retina or stroke
The visual disturbance associated with ocular migraines makes them very disturbing to sufferers and they can disrupt lives by limiting the sufferer's ability to perform tasks; driving, going to work or school, or even leaving the house may not be possible
Retinal Migraine
Retinal migraine is the less common of the subtypes. There is however a specific list of visual disturbances that have been reported by those with the condition:
- Partial loss of eyesight- 12%
- Complete loss of eyesight – 50%
- Blurred eyesight – 20%
- Dimmed eyesight – 7%
- Blindspot (scotoma) – 13%
In addition, some sufferers will experience flashes of light (scintillations)
These symptoms are only experienced in one eye and this is made clear when the affected eye is closed and it is noted that the vision in the other eye is normal. It is believed that the disturbances, in this case, are coming from issues within the eye itself whereas in cases where both eyes are affected (migraine with aura) the issues are in the brain
The visual disturbances are temporary and will last from a few seconds up to an hour and maybe during or after the headache itself begins
Causes
Like all types of migraine headaches, they have general triggers which include stress, hypertension, smoking, stress, tension, tiredness, and sensitivity to some foods
Some triggers that are specific to retinal migraines include:
- Looking at a screen for long periods of time
- Spending periods of time in harsh lighting such as fluorescent lighting
- Driving for long periods of time
- Any activity which is visually taxing
The exact physiology behind the occurrence of a retinal headache is not known for sure but a theory exists that the mechanism of the headache involves vasospasm or a narrowing of the blood vessels which supply the retina and ciliary body of the eye. The ciliary body contains the muscle which changes the shape of the lens when the eye is focusing
Risk factors
There are some groups of people who are considered to be more at risk of suffering from retinal headaches than others:
- Those people who are in their 20’s and 30’s
- Some women may be susceptible due to hormonal changes during the menstrual cycle
- Have historically suffered from other types of migraine
- If there is a family history of migraine
- People who suffer from atherosclerosis, sickle cell anaemia, or lupus
Diagnosis
There are no tests specifically aimed at identifying the presence of retinal headaches. Diagnosis involves looking at medical history, performing a physical examination, and ordering tests to exclude any other more serious causes of headaches with visual disturbance. A brain scan may be considered as a way of excluding a stroke as the cause and blood or urine tests may be carried out to check for lupus or sickle cell anaemia
In order that the headache can be diagnosed as retinal migraine, the visual disturbance must only affect one eye, it is temporary and has at least two of the following symptoms:
- The disturbance must last from a few minutes up to an hour
- The aura spreads gradually over a period off five minutes or more
- The aura is accompanied by or followed by (within an hour) a headache
Migraine with aura
A migraine is defined as ‘a recurrent throbbing headache that typically affects one side of the head and is often accompanied by nausea and disturbed vision’. The disturbed vision is the aura and may present as a warning to the onset of the headache or be present during the headache. Other symptoms include nausea, intense head pain, and hypersensitivity to light and sound
The visual symptoms associated with the aura tend to start in the centre of the field of visions and spread outwards. The disturbances may include:
- Changes in eyesight or loss of eyesight
- Flashes of light
- Shimmering spots or stars
- Zigzag lines which float across the line of vision
- Blind spots or scotomas
Some other disturbances may also occur including the following:
- Muscle weakness
- Difficulty with speech or language
- Numbness which may be felt as tingling in the hand that may spread along the limb or may be felt on one side of the face
It is important if you experience a migraine with aura that you seek medical help urgently; the reason for this is that it may also be a symptom of stroke or detached retina as is the case with retinal migraine
Causes
As in the case of retinal migraine, the physiological cause of migraines with aura is not really understood. There is some evidence either an electrical or chemical wave which moves across the part of the brain which processes the nerve impulses associated with vision (visual cortex) and it is this that causes the visual disturbances
Similar triggers to those associated with retinal migraine (and other forms of migraine) are also associated with migraines with aura:
- Stress
- Tiredness
- Too much screen time
- Driving for long periods
- Menstrual cycle
- Sensitivity to foods and medication
It is more likely that you will suffer from migraines with aura if you have a family history of the condition; it is also more common for women to suffer these headaches.
Conclusion
The management of retinal migraine is best if it is based on prevention rather than the approach of using medication to stop them once they have started.
This can be handled by keeping a log of when these headaches occur and noting any possible triggers that may have happened at that time. For instance, if you had spent all day in front of the computer which was unusual to you and you developed a retinal migraine then this would be a trigger to be avoided in future
If preventative medication is needed there are some drugs that may be considered:
- Calcium channel blockers
- Beta-blockers
- Amitriptyline (a tricyclic antidepressant)
- Some anti-seizure medication
General painkillers such as nonsteroidal anti-inflammatory drugs (NSAIDs) may be taken for the associated pain
As a migraine sufferer in general there is a small added risk of having a stroke
Sources
- Retinal Migraine https://www.nhs.uk/conditions/retinal-migraine/
- Should I be concerned about ocular migraines https://www.brainandlife.org/articles/should-i-be-concerned-about-ocular-migraines/
- Ocular Migraine https://migraine.com/migraine-types/ocular-migraine/
- An overview of ocular migraines https://www.verywellhealth.com/retinal-migraine-3862386
