What is the appropriate initial assessment and management for a patient presenting with a drooping upper eyelid (ptosis)?

Drooping Eyelid (Ptosis): Initial Assessment and Management

The initial assessment of ptosis must immediately prioritize pupillary examination to rule out life-threatening causes (third nerve palsy from aneurysm or carotid dissection), followed by systematic evaluation of levator function, fatigability, and associated neurological signs to guide definitive management. 1, 2, 3

Immediate Life-Threatening Causes to Rule Out

Pupillary examination is the single most critical first step and must be performed in both bright and dim illumination to detect: 2, 3

• Mydriasis (dilated pupil): Suggests third nerve palsy from intracranial aneurysm—requires emergency neuroimaging within 24 hours 3
• Miosis (constricted pupil): Suggests Horner syndrome from carotid dissection until proven otherwise—requires urgent vascular imaging 3
• Normal pupils: Myasthenia gravis characteristically spares pupils, which is a key distinguishing feature 1

Systematic Clinical Assessment Algorithm

Step 1: Characterize the Ptosis Pattern

Measure objective parameters to quantify severity: 4, 5

• Palpebral fissure height: Normal 8-12 mm 5
• Marginal reflex distance (MRD-1): Distance from upper lid margin to corneal light reflex; normal ≥4 mm 5
• Levator function: Measure excursion from downgaze to upgaze with frontalis muscle immobilized 4, 5
  • Good: >10 mm
  • Fair: 5-10 mm
  • Poor: <5 mm

Step 2: Assess for Fatigability (Myasthenia Gravis)

Variable ptosis worsening with fatigue is pathognomonic for myasthenia gravis. Perform bedside tests: 1, 6

• Ice pack test: Apply ice over closed eyes for 2 minutes; ≥2 mm improvement in ptosis is highly specific for myasthenia (sensitivity 86%, specificity approaching 100%) 1, 6
• Rest test: Have patient close eyes for 5 minutes; improvement suggests myasthenia 1
• Diurnal variation: Ask if ptosis worsens by evening—classic for myasthenia 6, 3

If myasthenia suspected, order acetylcholine receptor (AChR) antibodies (sensitivity 80-88% for generalized disease, 40-77% for ocular disease; specificity 98-100%) 1, 6

Step 3: Identify Mechanical or Structural Causes

Perform slit-lamp examination to detect: 2

• Floppy eyelid syndrome: Upper lid easily everts, associated with obstructive sleep apnea and obesity—requires sleep study referral 7
• Orbital mass or proptosis: Requires MRI orbits with and without contrast 2
• Conjunctival inflammation or scarring: May indicate cicatricial processes 7

Step 4: Age-Specific Considerations

In children <5 years with ptosis: 7, 2

• Orbital/periorbital plexiform neurofibroma (OPPN) has nearly 100% incidence of blepharoptosis 7, 2
• Examine for palpable "bag of worms" mass, proptosis, or periorbital asymmetry 7
• Do not biopsy if neurofibromatosis type 1 (NF1) suspected—obtain MRI brain and orbits with contrast to define extent 7
• Screen for glaucoma (25% incidence with OPPN) and amblyopia 7

In adults: 4, 8

• Aponeurotic ptosis (most common acquired form) presents with high or absent eyelid crease and good levator function 4, 8
• Neurogenic causes require full cranial nerve examination 3, 5

Urgent Referral Criteria

Refer to ophthalmology emergently (within 24 hours) if: 2, 3

• Pupil-involving third nerve palsy (aneurysm risk)
• Acute onset with severe headache or neck pain (dissection risk)
• Progressive ptosis with diplopia and neurological signs (brainstem pathology)

Refer urgently (within 1-4 weeks) if: 7, 2

• Suspected myasthenia with respiratory symptoms or dysphagia (myasthenic crisis risk) 1
• Orbital mass or proptosis detected 2
• Children with OPPN and visual decline 7

Initial Management Pending Specialist Evaluation

For Suspected Myasthenia Gravis

Start pyridostigmine 30 mg orally three times daily, gradually increasing to maximum 120 mg four times daily as tolerated, while awaiting AChR antibody results 1, 6

• Note: Approximately 50% of ocular myasthenia patients show minimal response to pyridostigmine alone, which does not exclude the diagnosis 1
• Monitor for respiratory compromise with pulmonary function testing, as 50-80% of ocular myasthenia progresses to generalized disease within 2 years 1

For Floppy Eyelid Syndrome

Temporary relief with eyelid taping at night or protective shield while sleeping 7

• Apply preservative-free lubricants for symptomatic relief 7
• Refer for sleep study given association with obstructive sleep apnea 7

For Mechanical Ptosis

Treat underlying cause (e.g., contact lens-related giant papillary conjunctivitis requires lens discontinuation; orbital inflammation requires anti-inflammatory therapy) 7

Common Pitfalls to Avoid

• Missing pupil involvement: Always examine pupils in both bright and dim light—pupil abnormalities exclude myasthenia and suggest neurological emergency 1, 2, 3
• Overlooking fatigability: Variable ptosis worsening throughout the day is myasthenia until proven otherwise—perform ice pack test 1, 6
• Delaying imaging in children: OPPN requires MRI even if ptosis appears isolated to eyelid, as full tumor extent may not be visible externally 7
• Assuming benign aponeurotic ptosis: Always assess levator function and Bell's phenomenon (lack predicts postoperative corneal exposure risk) 3
• Ignoring associated symptoms: Dysphagia, dysarthria, or shortness of breath with ptosis mandates urgent myasthenia evaluation 1, 6

Definitive Treatment Planning

Surgical correction is the mainstay for most ptosis once urgent causes are excluded: 4, 3

• Minimal ptosis (1-2 mm) with good levator function: Müller's muscle-conjunctival resection 4
• Moderate ptosis (3-4 mm) with fair levator function (5-10 mm): Levator advancement 4
• Severe ptosis (>4 mm) with poor levator function (<5 mm): Frontalis suspension 4

Defer surgery in: 7

• Active myasthenia (treat medically first)
• Children with OPPN during rapid growth phase (<8 years)—high recurrence risk 7
• Inadequate Bell's phenomenon without addressing corneal protection 3