Because of the close correlation between eyes and headaches, ophthalmologists are often the first doctors to assess patients with headaches or migraines, visual disturbances associated with headaches and eye pain. In fact, eye pain and visual disturbances are symptoms many times of neurological origin.
The International Headache Society classifies headaches into two main categories: primary headaches and secondary headaches.1
Primary headaches include various types of migraine:
- tension headache
- cluster headache
- paroxysmal migraine
- other miscellaneous headaches not associated with a structural lesion.
Secondary headaches are, on the other hand, associated with1:
- head injuries
- vascular disorders
- other intracranial processes (such as mass lesions, infections, metabolic disorders, drugs, cranial neuralgia)
- other craniofacial disorders.
Migraine with aura and migraine variants with visual afferent symptoms
In addition to headaches, visual manifestations are the most common symptoms of migraine and, more often than not, these fall under the so-called 'aura'. The aura consists of neurological symptoms that precede, accompany or, rarely, follow a migraine. The symptoms of an aura, which usually affect both eyes, usually develop within 5-20 minutes and last less than an hour. Visual symptoms are classified as positive or negative.1
Positive symptoms include:
- the vision of sparkling spots (called scotomas)
- the vision of flashes (phosphenes)
- heat waves
- kaleidoscopic effects
- fragmented vision (as of cracked glass).
All these symptoms persist even when the eyelids are closed. In addition, migraine is often accompanied by blurred vision. As with other migraine aura symptoms, visual disturbances often develop gradually and may progress from one type to another.1
Negative symptoms include1:
- homonymous hemianopsia
- concentric narrowing of the visual field (tunnel vision)
- cortical blindness
- transient loss of monocular visual acuity.
A special case of adverse symptoms is transient monocular visual loss. Vision loss may be partial (curtain, shadow or tunnel vision) or complete, with sudden or gradual onset and resolution. It usually lasts from 4 to 45 minutes, although it can last from seconds to hours. There need not be an accompanying headache.1
When migraine is associated with headaches and transient monocular visual symptoms that last less than one hour, it is called retinal migraine. The latter is a rare condition, usually consisting of negative symptoms such as scotoma or loss of vision.1
Most people with migraine with aura experience isolated, headache-free auras in their lives. Many migraineurs report triggers associated with the visual environment, such as bright lights, fluorescent lights, strobe lights, flickering computer screens and busy visual environments, such as grocery shop aisles.1
Ephemeral and autonomous manifestations of migraine
During a migraine attack, abnormalities of the eyelids, pupils and ocular motility are occasionally present. For example, benign episodic pupillary mydriasis produces anisocoria (i.e. a different pupil width), which may be associated with blurred vision, head pain, photophobia, conjunctival injection or transient visual obscurations. Patients with migraine may also experience diplopia (visual disturbance involving double vision of the image) and cranial nerve palsy. The latter, which affects the oculomotor nerve, occurs in oculomotor ophthalmoplegic migraine, which, however, is no longer considered a type of migraine by the International Headache Society because it is often associated with a secondary cause.1
Other types of migraine may present ophthalmic symptoms: cluster headache, for example, affects the ipsilateral eye. During a migraine attack, ptosis, miosis and anisocoria may occur. Patients may also manifest conjunctival injection, eyelid oedema and lacrimation.2 A form of migraine similar to cluster headache is paroxysmal migraine, whose ophthalmic features include ptosis and miosis, lacrimation, conjunctival injection and eyelid oedema. Many patients also present with photophobia.2 SUNCT (Unilateral short-lasting neuralgiform headache with conjunctival injection and lacrimation) and SUNA (Unilateral short-lasting neuralgiform headache with cranial autonomic symptoms) are rare forms of primary headache in which lacrimation and eyelid oedema occur.2
Other causes of headache and periocular pain
- Dry eye is a very common disorder, affecting 10% to 15% of adults. It is associated with tear deficiency states or excessive tear evaporation. Since the cornea is richly innervated, dryness of the corneal surface can be painful. Dry eye can mimic headaches and drugs used to treat headaches can cause or worsen this condition.2
- Angle-closure glaucoma is caused by blockage of the drainage of aqueous humour (the fluid contained in the eye) resulting in a rapid increase in intraocular pressure. Acute angle-closure glaucoma is characterised by pain, blurred vision, rainbow-coloured halos around lights, nausea and vomiting. Because of these characteristics, subacute angle-closure glaucoma can mimic migraine.2
- Many other conditions produce orbital inflammatory diseases and the differential diagnosis includes systemic disorders, neoplasms, congenital malformations, infectious diseases and trauma.2
Bibliography
- Friedman DI. et al. Headache and the Eye. Curr Pain Headache Rep. 2008 Aug;12(4):296-304.
- Friedman DI. The eye and headache. Ophthalmol Clin North Am. 2004 Sep;17(3):357-69
Dr. Carmelo Chines
Direttore responsabile