Eye pain

Eye pain is pain felt in or around the eye (ocular), behind it (retro-orbital) or around the orbit (periocular), with or without redness. It can arise from the eye surface, intraocular structures, optic nerve, orbit, cranial nerves, or referral from the head, face, sinuses and teeth.

Anatomy. The cornea, iris and ciliary body are innervated by the ophthalmic division of the trigeminal nerve. The optic nerve sheath, extraocular muscles, orbit and periorbita are also pain sensitive. Referred pain from the sinuses, teeth, temporal arteries and brainstem can present as eye pain.

Classification. Ocular surface (corneal, conjunctival, lid), intraocular (glaucoma, uveitis), optic nerve, orbital and muscle, neuralgic and neurovascular headache, referred, and functional.

Key distinctions. Pain on eye movement suggests optic neuritis or orbital disease. Photophobia suggests corneal or uveal inflammation. Pain with a normal eye and autonomic features suggests cluster headache. A burning, gritty feeling suggests dry eye.

History. Site, character, severity, onset, duration, relation to eye movement and light, photophobia, redness, discharge, vision loss, halos, double vision, floaters. Also: headache, nausea, jaw claudication, scalp tenderness, facial pain, sinus symptoms, toothache, rash, contact lens use, screen use, trauma, recent surgery, autonomic symptoms (tearing, nasal congestion, ptosis), neurological symptoms, systemic disease, and previous episodes.

Drug history. Topical drops and preservatives, topiramate and other drugs causing angle closure, anticholinergics, and drugs causing dry eye (antihistamines, isotretinoin, antidepressants).

Examination. Visual acuity, colour vision (Ishihara plates), pupils (relative afferent pupillary defect), visual fields, eye movements (pain on movement, diplopia), intraocular pressure, slit lamp (cornea, anterior chamber, lens), fundus (disc swelling, pallor), proptosis, lid, temporal artery tenderness and pulses, sinuses, teeth, neck and cranial nerves.

Red flags

• Reduced vision, colour desaturation or relative afferent pupillary defect (optic neuritis)
• Severe pain with a red eye, halos, nausea or fixed pupil (angle closure)
• Corneal opacity, ulcer or contact lens related pain
• Proptosis, painful movement, or lid swelling with fever (orbital cellulitis)
• Jaw claudication, scalp tenderness, headache and age over 50 (giant cell arteritis)
• Horner syndrome with neck pain or recent neck trauma (carotid dissection)
• Sudden severe headache with third nerve palsy (posterior communicating aneurysm)
• Trauma or chemical exposure

Special groups. Children: optic neuritis and orbital cellulitis. Pregnancy: pre-eclampsia can cause visual pain and disturbance. Older adults: giant cell arteritis and angle closure. Region specific: trachoma, onchocerciasis and vitamin A deficiency.

Ocular surface and anterior segment

• Corneal abrasion, foreign body, keratitis, ulcer, recurrent erosion, ultraviolet keratitis
• Dry eye and blepharitis, meibomian gland dysfunction, conjunctivitis, contact lens overwear
• Acute angle closure glaucoma, anterior uveitis, scleritis, endophthalmitis, lens subluxation

Optic nerve and orbit

• Optic neuritis (multiple sclerosis, neuromyelitis optica spectrum disorder, MOG antibody disease, infection, sarcoidosis), ischaemic optic neuropathy (arteritic and non-arteritic)
• Orbital cellulitis, thyroid eye disease, orbital inflammatory syndrome (idiopathic orbital pseudotumour), myositis, orbital tumour, carotid cavernous fistula
• Tolosa Hunt syndrome, cavernous sinus thrombosis, ophthalmoplegic migraine

Neurovascular and headache

• Cluster headache, migraine, tension type headache, paroxysmal hemicrania, hemicrania continua, SUNCT
• Giant cell arteritis, carotid artery dissection, aneurysm (posterior communicating)
• Trigeminal neuralgia, post-herpetic neuralgia, herpes zoster ophthalmicus
• Raised intracranial pressure (idiopathic intracranial hypertension)

Referred and other

• Sinusitis, dental disease, temporomandibular disorder, nasopharyngeal carcinoma, cervical spine disease
• Convergence insufficiency, refractive error, eye strain (asthenopia), uncorrected hyperopia
• Functional ocular pain, depression and anxiety

Reasoning. Measure acuity and look at the eye. If the eye is normal, think optic nerve, orbit and neurovascular causes.

First line. Visual acuity, pupils, colour vision, visual fields, fluorescein staining, tonometry, slit lamp, dilated fundus, and examination of the head and face.

Targeted tests.

• MRI brain and orbits with gadolinium and fat suppression for optic neuritis, orbital disease and demyelination; CT orbits for orbital cellulitis and trauma; MR or CT angiography for suspected dissection, aneurysm or carotid cavernous fistula.
• ESR, C reactive protein and platelet count for suspected giant cell arteritis (a normal ESR does not exclude it), with temporal artery ultrasound or biopsy (biopsy remains useful for up to 2 weeks after steroids start).
• Aquaporin-4 and MOG antibodies, antinuclear antibody, angiotensin converting enzyme, syphilis serology, and chest radiograph for optic neuritis of uncertain cause.
• Visual evoked potentials and optical coherence tomography for optic nerve disease.
• Thyroid function and thyroid antibodies for thyroid eye disease.
• Lumbar puncture with opening pressure for suspected idiopathic intracranial hypertension (over 25 cmH2O in adults is abnormal) or neuroinflammation, after imaging.
• Tear break up time and Schirmer test (under 5 mm in 5 minutes) for dry eye.
• Sinus CT and dental radiographs for suspected referred causes.

Limitations. Normal eye examination does not exclude optic neuritis early. MRI can be normal in early orbital disease.

Giant cell arteritis. Prednisolone 40 to 60 mg orally each morning started before biopsy, with aspirin 75 mg daily; if visual symptoms, methylprednisolone 500 mg to 1 g IV daily for 3 days; give a proton pump inhibitor and bone protection; same day specialist review.

Optic neuritis. Methylprednisolone 1 g IV daily for 3 to 5 days (or oral methylprednisolone 500 mg to 1 g daily) under neurology and ophthalmology care, to speed recovery; do not use low dose oral prednisolone alone (increased recurrence). Plasma exchange for severe cases not responding.

Acute angle closure. Acetazolamide 500 mg IV or orally then 250 mg orally every 6 hours, timolol 0.5 percent 1 drop, apraclonidine 1 percent 1 drop, and pilocarpine 2 percent once pressure is falling; same day ophthalmology for iridotomy.

Keratitis and corneal ulcer. Same day ophthalmology: fluoroquinolone drops (ofloxacin 0.3 percent or moxifloxacin 0.5 percent, 1 drop every 15 to 60 minutes initially) after scraping, with cycloplegic drops.

Orbital cellulitis. Admit. Ceftriaxone 2 g IV every 12 hours plus metronidazole 500 mg IV every 8 hours; urgent CT, ENT and ophthalmology.

Cluster headache. 100 percent oxygen 12 to 15 L/min by non-rebreather mask for 15 minutes, and sumatriptan 6 mg subcutaneously, repeated after 1 hour (maximum 12 mg in 24 hours). Prevention with verapamil 80 mg orally three times daily increased by 80 mg every 2 weeks to 240 to 480 mg daily, with an ECG before each increase; neurology referral.

Migraine. Sumatriptan 50 to 100 mg orally at onset, repeated after 2 hours (maximum 300 mg in 24 hours), with ibuprofen 400 to 600 mg or paracetamol 1 g; contraindicated in ischaemic heart disease, uncontrolled hypertension, stroke, and ergot or monoamine oxidase inhibitor use.

Herpes zoster ophthalmicus. Valaciclovir 1 g orally three times daily for 7 days (adjusted for kidney function: creatinine clearance 30 to 49 mL/min, 1 g every 12 hours; 15 to 29 mL/min, 1 g daily; under 15 mL/min, 500 mg daily), analgesia, and same day ophthalmology.

Dry eye and blepharitis. Lubricants (hypromellose 0.3 percent or sodium hyaluronate 0.1 to 0.2 percent, 1 drop 4 to 6 times daily, preservative free when frequent), warm compresses and lid hygiene, omega 3 supplements (evidence is limited). Treat lid disease (doxycycline 100 mg orally daily for 6 to 12 weeks; avoid in pregnancy and in children under 12 years). Topical ciclosporin 0.05 percent twice daily for moderate to severe disease by ophthalmology. Screen for Sjogren syndrome.

Eye strain and refractive error. Correct refraction, use of 20 20 20 breaks (every 20 minutes look at an object 20 feet or 6 metres away for 20 seconds), and ergonomic changes.

Thyroid eye disease. Smoking cessation, euthyroid state, lubricants, selenium 100 micrograms orally twice daily for 6 months in mild disease, and ophthalmology and endocrinology care. Moderate to severe disease: methylprednisolone 500 mg IV weekly for 6 weeks, then 250 mg weekly for 6 weeks (cumulative dose under 8 g), with monitoring of liver function, and teprotumumab by specialists.

Sinusitis, dental and temporomandibular causes. Amoxicillin 500 mg orally three times daily for 5 days for bacterial sinusitis or dental abscess, with dental referral; ibuprofen 400 mg orally three times daily with food for temporomandibular disorder.

Neuralgias. Carbamazepine 100 mg orally twice daily, increased by 100 to 200 mg every 2 to 3 days to a usual 400 to 800 mg daily (maximum 1.6 g daily). Sodium, blood count and liver function are monitored, with HLA-B*1502 testing in people of Han Chinese, Thai or other South East Asian ancestry.

Carotid dissection and aneurysm. Emergency stroke and neurosurgical care.

Monitoring. Visual acuity, colour vision and fields at each review for optic nerve disease; intraocular pressure with steroid treatment; blood count, glucose and blood pressure on high dose corticosteroids.

Referral and escalation. Same day ophthalmology for red flags and for any pain with reduced vision. Neurology for optic neuritis and neurovascular headache. Same day for suspected giant cell arteritis. ENT, dentistry or maxillofacial surgery for referred causes.

Admission criteria. Orbital cellulitis, angle closure not settling, endophthalmitis, giant cell arteritis with visual loss, carotid dissection, or aneurysm.

Discharge and safety netting. Return for reduced vision, double vision, severe headache, eye redness with halos, jaw claudication, scalp tenderness, swelling around the eye, fever, or pain not improving in 1 week.