What are the possible causes and treatments for sudden right-sided eyelid drooping (ptosis)?

Right-Sided Eyelid Drooping (Ptosis): Causes and Management

Sudden unilateral eyelid drooping requires urgent evaluation to rule out life-threatening neurogenic causes including carotid dissection, intracranial aneurysm, or oculomotor nerve palsy before considering benign etiologies. 1

Immediate Assessment: Rule Out Emergencies

The first priority is distinguishing "urgent ptosis" from "benign ptosis" through systematic clinical examination 1:

Critical Red Flags Requiring Emergency Evaluation

• Pupillary abnormalities: Examine for miosis (suggesting Horner's syndrome from carotid dissection) or mydriasis (suggesting intracranial aneurysm compressing the oculomotor nerve) 1
• Associated diplopia or strabismus: May indicate oculomotor nerve palsy from aneurysm, herniation, or cavernous sinus pathology 2, 3
• Variable ptosis with fatigue: Suggests myasthenia gravis, which can progress to life-threatening generalized disease in 50-80% of cases initially presenting with ocular symptoms 2
• Associated neurologic deficits: Weakness, speech changes, or sensory disturbances suggest stroke or mass lesion 3

Specific Examination Findings by Etiology

For Oculomotor Nerve Palsy 4:

• Ptosis with impaired eye elevation, depression, and adduction
• Pupil involvement (mydriasis) suggests compressive lesion requiring emergency imaging
• Pupil-sparing palsy more consistent with microvascular ischemia (diabetes, hypertension)

For Horner's Syndrome 1, 3:

• Mild ptosis (1-2mm) with miosis
• Anhidrosis (decreased sweating) on affected side
• Requires urgent vascular imaging to exclude carotid dissection

For Myasthenia Gravis 2:

• Variable ptosis worsening with sustained upgaze or end of day
• Positive ice pack test (2 minutes for ptosis, 5 minutes for strabismus reduces symptoms)
• Cogan lid-twitch sign
• May have slow ocular saccades and variable strabismus

Diagnostic Workup

Clinical Testing Sequence

1. Levator function assessment: Measure excursion of upper lid from downgaze to upgaze (normal >15mm) 5, 1
2. Bell's phenomenon: Check for upward eye rotation with forced closure (absence predicts postoperative corneal exposure risk) 1
3. Phenylephrine test: 2.5% drops assess Müller's muscle function in aponeurotic ptosis 1
4. Ice pack test: Apply for 2-5 minutes if myasthenia suspected 2

Laboratory and Imaging

For suspected myasthenia 2:

• Antiacetylcholine receptor antibodies (95% sensitive for generalized, 86% for ocular)
• Anti-MuSK antibodies if seronegative
• Single-fiber electromyography (>90% sensitive for ocular myasthenia)

For neurogenic causes 1, 4:

• MRI/MRA of brain and orbits for oculomotor palsy
• CT angiography of neck for Horner's syndrome
• Chest imaging if Horner's (apical lung tumor consideration)

Classification and Treatment by Etiology

Aponeurotic Ptosis (Most Common Acquired Form) 6

Characteristics: Gradual onset, good levator function (>10mm), high or absent lid crease 5, 6

Surgical approach 5:

• Mild ptosis (1-2mm): Müller's muscle-conjunctival resection or Fasanella-Servat procedure
• Moderate ptosis (3-4mm) with levator function 5-10mm: Levator advancement or aponeurotic repair
• Severe ptosis (>4mm) with levator function <5mm: Frontalis suspension

Neurogenic Ptosis

Myasthenia gravis 2:

• First-line: Pyridostigmine bromide 2-4 times daily (50% response for strabismus)
• Second-line: Corticosteroids (66-85% response rate)
• Immunosuppression (azathioprine, efgartigimod alfa-fcab) for refractory cases
• Surgery delayed until medical stabilization (6+ months stability)

Oculomotor nerve palsy 3, 4:

• Treat underlying cause (vascular risk factor management for microvascular)
• Observe 3-6 months for spontaneous recovery
• Prism therapy for diplopia during recovery
• Surgery if stable after 6 months

Horner's syndrome 1, 3:

• Address underlying cause (carotid dissection, tumor)
• Surgical correction rarely needed due to mild ptosis

Myogenic Ptosis

Thyroid eye disease 2:

• Ocular lubricants and punctal plugs for exposure 2
• Smoking cessation mandatory 2
• Teprotumumab for active disease (reduces proptosis, muscle size, and diplopia) 2
• Surgery delayed until 6 months stability after inflammatory phase
• Sequence: orbital decompression → strabismus surgery → eyelid surgery 2

Surgical Timing and Considerations

Delay surgery until 2, 5:

• Angle of deviation stable for 4-6 months (thyroid eye disease requires 6 months)
• Inflammatory markers normalized
• Medical optimization complete

Congenital ptosis exception: Early surgery (before age 5-7) to prevent amblyopia 5

Common Pitfalls

• Operating prematurely in thyroid eye disease: Decompression significantly alters alignment; strabismus surgery before decompression may worsen proptosis 2
• Missing myasthenia: 50-80% progress to generalized disease; early recognition prevents respiratory crisis 2
• Inadequate Bell's phenomenon assessment: Predicts postoperative corneal exposure requiring aggressive lubrication 1
• Ignoring pupil in oculomotor palsy: Pupil involvement mandates emergency aneurysm evaluation 1

Postoperative Risks

Surgical complications include 5:

• Overcorrection/undercorrection requiring revision
• Temporary lagophthalmos (difficulty closing eye)
• Corneal exposure if inadequate Bell's phenomenon
• Asymmetry (eyelids may not appear perfectly symmetrical)
• Infection, bleeding (rare)