Ptosis

Ptosis is drooping of the upper eyelid, with a reduced margin reflex distance (distance from pupil light reflex to upper lid margin under 3 mm; normal about 4 to 5 mm). It may be congenital or acquired, unilateral or bilateral, and constant or fluctuating.

Anatomy. The levator palpebrae superioris (oculomotor nerve) lifts the lid and is assisted by Muller muscle (sympathetic supply). Frontalis provides accessory lift. Failure of any component causes ptosis.

Classification.

• Neurogenic: third nerve palsy, Horner syndrome, myasthenia gravis, supranuclear lesions.
• Myogenic: congenital myogenic, chronic progressive external ophthalmoplegia, myotonic dystrophy, oculopharyngeal dystrophy, muscle disease.
• Aponeurotic: involutional (levator dehiscence), after cataract surgery, contact lens wear, eye rubbing, chronic oedema.
• Mechanical: lid mass, scarring, oedema, orbital disease.
• Pseudoptosis: contralateral lid retraction, enophthalmos, hypotropia, dermatochalasis, blepharospasm.

Key distinctions. Ptosis with a dilated pupil and eye turned down and out indicates third nerve palsy. Ptosis with miosis and anhidrosis indicates Horner syndrome. Ptosis that worsens with fatigue and upgaze indicates myasthenia gravis.

History. Onset (sudden, gradual, since birth; old photographs), laterality, fluctuation (worse in the evening), double vision, pain, headache, neck pain or trauma, facial sweating, dysphagia, dysarthria, limb weakness, dyspnoea, weight loss, cough, eye surgery, contact lens wear, eye rubbing, family history, and drugs.

Drug history. Botulinum toxin, topical alpha agonist and prostaglandin drops (periorbitopathy), corticosteroids (ptosis in chronic use), opioids, and drugs that worsen myasthenia (aminoglycosides, fluoroquinolones, macrolides, magnesium, beta blockers).

Examination.

• Margin reflex distance 1 (pupil reflex to upper lid margin), levator function (lid excursion from downgaze to upgaze with frontalis blocked; over 12 mm is good, 4 mm or under is poor), lid crease position, lid lag, pupils (size and reaction in light and dark), eye movements, ocular alignment, fatigability on sustained upgaze for 60 seconds, Cogan lid twitch, ice pack test, and enhanced ptosis (lifting the more ptotic lid increases ptosis on the other side: Hering law).
• Hair, skin and facial examination for sweating (Horner), neck and thyroid, chest, neurological examination including cranial nerves, bulbar function, proximal muscle strength, and respiratory reserve.

Red flags

• Painful or sudden ptosis with a dilated pupil or double vision (aneurysm, carotid dissection)
• Horner syndrome with neck or facial pain, recent trauma, or neurological signs
• Ptosis with weakness, dysphagia, dysarthria or breathlessness (myasthenic crisis)
• Ptosis with diplopia and headache
• Child with ptosis covering the pupil (amblyopia risk), or with a head tilt
• Lid mass, ulcer or other tumour sign
• Weight loss, smoker, cough or shoulder and arm pain (Pancoast tumour)
• Thunderclap headache
• Recent head trauma or neck manipulation

Special groups. Children: congenital ptosis, amblyopia, Marcus Gunn jaw winking, and neuroblastoma (acquired Horner). Pregnancy: myasthenia gravis. Older adults: involutional ptosis and stroke. Region specific: botulism, leprosy and snakebite (neurotoxic).

Neurogenic

• Third nerve palsy: posterior communicating artery aneurysm, microvascular (diabetes, hypertension), tumour, trauma, cavernous sinus lesion, giant cell arteritis, midbrain stroke, uncal herniation, meningitis
• Horner syndrome: carotid dissection, apical lung tumour (Pancoast), brainstem stroke (lateral medullary), neck trauma or surgery, cluster headache, thyroid and cervical lesions, congenital, neuroblastoma
• Myasthenia gravis (ocular and generalised), Lambert Eaton syndrome, botulism, snake neurotoxin, organophosphate toxicity
• Supranuclear and cortical lesions, Marcus Gunn jaw winking, apraxia of lid opening, blepharospasm

Myogenic

• Congenital myogenic ptosis, chronic progressive external ophthalmoplegia (mitochondrial disease, Kearns Sayre), oculopharyngeal muscular dystrophy, myotonic dystrophy, thyroid and inflammatory myopathy

Aponeurotic and mechanical

• Involutional ptosis, post-surgical, contact lens, eye rubbing, floppy eyelid, blepharochalasis
• Lid mass (chalazion, tumour, neurofibroma, haemangioma), scarring and trauma, orbital tumour, thyroid eye disease (usually retraction), cicatricial disease, lid oedema
• Dermatochalasis (pseudoptosis), enophthalmos, hypotropia, and contralateral lid retraction

Reasoning. Determine whether ptosis is neurogenic (pupils, eye movements, fatigability), then image for painful or pupil involving third nerve palsy and Horner syndrome, and test for myasthenia gravis in fluctuating or fatigable ptosis.

First line. Margin reflex distance, levator function, pupil examination in light and dark, eye movements, fatigue tests, and a full neurological examination.

Targeted tests.

• Apraclonidine 0.5 or 1 percent drops (1 drop each eye; a pupil that dilates and a lid that rises by 1 mm or more in a Horner pupil confirms the diagnosis after 30 to 45 minutes; false negatives in acute disease within 1 to 2 weeks of onset). Cocaine drops 4 or 10 percent and hydroxyamphetamine localisation tests are alternatives where available.
• Ice pack test (cold on closed lid for 2 minutes with improvement of at least 2 mm supports myasthenia), acetylcholine receptor and muscle specific tyrosine kinase antibodies, single fibre electromyography and repetitive nerve stimulation, chest CT for thymoma, and thyroid function.
• Emergency CT head, CT angiography and MR angiography for painful or pupil involving third nerve palsy, thunderclap headache, or neurological signs. CT or MR angiography of head and neck from aortic arch to circle of Willis for painful Horner syndrome. MRI brain with gadolinium for isolated third nerve palsy in the young or with other features. Chest radiograph and CT chest apex for Horner syndrome without a cause.
• Blood tests: glucose and HbA1c, ESR, C reactive protein and platelets (giant cell arteritis), creatine kinase, lactate (mitochondrial disease), and genetic tests by suspicion.
• Lumbar puncture after imaging for suspected meningitis, demyelination, carcinomatous meningitis, or Miller Fisher syndrome (anti-GQ1b antibodies).
• Urinary catecholamines (vanillylmandelic acid, homovanillic acid) and MRI neck for acquired Horner syndrome in a child (neuroblastoma).

Limitations. Antibody tests are negative in about 50 percent of ocular myasthenia. A normal angiogram does not exclude small aneurysm in a partial third nerve palsy. Apraclonidine can be falsely negative in early Horner syndrome.

Third nerve palsy with pupil involvement or pain, or thunderclap headache (emergency). CT and CT angiography, neurosurgical referral for aneurysm (coiling or clipping), blood pressure control, and emergency stroke care where indicated.

Painful Horner syndrome or suspected carotid dissection. Emergency stroke care: alteplase 0.9 mg/kg IV (maximum 90 mg, 10 percent as a bolus over 1 minute and the remainder over 60 minutes) within 4.5 hours when haemorrhage is excluded and criteria are met; aspirin 300 mg orally daily when thrombolysis is not given; antithrombotic therapy by stroke specialists.

Pancoast tumour and other malignancy. Urgent oncology care with staging and biopsy.

Giant cell arteritis. Prednisolone 40 to 60 mg orally each morning started before biopsy, with aspirin 75 mg daily; methylprednisolone 500 mg to 1 g IV daily for 3 days with visual symptoms; same day specialist review.

Myasthenia gravis.

• Ocular disease: pyridostigmine 30 to 60 mg orally three to four times daily (maximum 240 mg daily; reduce in renal impairment), with prednisolone 10 to 20 mg daily increased slowly to 0.5 to 1 mg/kg on alternate days under neurology care (watch for transient worsening), and steroid sparing drugs (azathioprine 2 to 3 mg/kg daily) by specialists. Avoid drugs that worsen myasthenia.
• Myasthenic crisis (bulbar weakness, respiratory failure): intensive care, intravenous immunoglobulin 0.4 g/kg daily for 5 days or plasma exchange, monitoring of forced vital capacity and negative inspiratory force, and thymectomy by specialists for thymoma and in selected patients.

Microvascular third nerve palsy (pupil sparing, age over 50, vascular risk factors). Control blood pressure, glucose and lipids, aspirin 75 mg daily, exclude giant cell arteritis, and observe for recovery over 3 to 4 months; re-image if there is no recovery or new signs.

Botulism. Emergency care: trivalent antitoxin as available, respiratory support, and public health notification.

Congenital ptosis. Amblyopia screening and treatment, with surgery (frontalis sling for poor levator function, levator resection for fair or good function) at about 3 to 5 years of age, earlier when the pupil is covered or when a chin up posture develops.

Involutional and aponeurotic ptosis. Surgical repair (levator advancement or Muller muscle resection) when ptosis causes visual field obstruction or symptoms. Ptosis crutches and apraclonidine 0.5 percent 1 drop to the affected eye three times daily or oxymetazoline 0.1 percent 1 drop to the affected eye once daily for temporary lift in selected patients.

Mechanical ptosis. Treat the lid mass (excision, injection or drainage) and underlying disease.

Horner syndrome. Treat the cause; no treatment for ptosis is needed unless disfiguring (surgery or oxymetazoline).

Mitochondrial and myopathic ptosis. Genetic counselling, neurology and muscle disease care, and ptosis surgery with caution (exposure keratopathy); lubricants for dryness.

Chronic progressive external ophthalmoplegia. Cardiac screening (ECG, echocardiography, Holter) for conduction defects.

Monitoring. Review at 1 to 2 weeks for acute neurogenic ptosis and weekly measurement of lid height, eye movement and pupil. Child with ptosis: refraction and amblyopia check every 3 to 6 months.

Referral and escalation. Immediate neurosurgical, stroke and ophthalmology for third nerve palsy with pupil involvement, painful Horner syndrome and thunderclap headache. Same day for myasthenic symptoms with bulbar or respiratory features. Neurology for myasthenia gravis and myopathy. Paediatric ophthalmology for congenital ptosis. Oculoplastic surgery for repair.

Admission criteria. Suspected aneurysm or dissection, stroke, myasthenic crisis, botulism, rapidly progressive neurological syndromes, or giant cell arteritis with visual loss.

Discharge and safety netting. Return for new double vision, severe headache, neck pain, weakness, dysphagia, difficulty breathing, or increasing ptosis.