What is the appropriate workup for a patient presenting with ptosis (drooping of the eyelid)?

Diagnostic Approach for Ptosis (Drooping of the Eyelid)

The appropriate workup for ptosis should include a comprehensive eye examination with evaluation for anisocoria, pupillary responses, sensorimotor examination, and fundus examination to identify potential neurological deficits and rule out life-threatening conditions. 1

Initial Assessment

• Determine if ptosis is unilateral or bilateral, as this helps narrow down potential etiologies 2
• Assess severity of ptosis (minimal: 1-2mm, moderate: 3-4mm, severe: >4mm) 2
• Evaluate for pupillary abnormalities in both bright and dim illumination to identify potential neurological causes 1
• Perform complete sensorimotor examination to detect strabismus and associated neurological symptoms 1
• Conduct fundus examination to check for papilledema or optic atrophy 1
• Measure levator function, which is crucial for determining surgical approach if needed 2, 3

Key Diagnostic Considerations Based on Associated Findings

• Ptosis with pupillary involvement (third nerve palsy):

  • Requires urgent evaluation for compressive lesions, especially posterior communicating artery aneurysm 1
  • Immediate neuroimaging with MRI or CTA is recommended 1

• Variable ptosis that worsens with fatigue:

  • Perform ice test or rest test to help diagnose myasthenia gravis 1
  • Consider acetylcholine receptor antibody testing even with negative initial results 1, 4

• Ptosis with proptosis or suspected orbital mass:

  • MRI orbits without and with contrast is necessary 1
  • Consider orbital inflammatory conditions including thyroid eye disease and IgG4-related disease 1

• Ptosis with associated neurological symptoms:

  • Consider brainstem pathology affecting the third nerve nucleus or fascicle 1
  • MRI head and orbits without and with contrast is recommended 1

Etiological Classification to Guide Workup

• Aponeurotic ptosis (most common acquired form):

  • Typically age-related or post-surgical 5
  • Good levator function with normal pupillary responses 5

• Neurogenic ptosis:

  • Evaluate for third nerve palsy, Horner's syndrome, or myasthenia gravis 5
  • For Horner's syndrome, look for miosis and anhidrosis 5

• Myogenic ptosis:

  • Consider chronic progressive external ophthalmoplegia and other muscular disorders 5, 3
  • May require additional neurological evaluation 5

• Mechanical ptosis:

  • Look for eyelid masses, edema, or inflammation 5, 3
  • Examine for dermatochalasis or blepharochalasis 5

• Traumatic ptosis:

  • Detailed history of injury is essential 2, 3
  • Evaluate for associated orbital fractures or nerve damage 2

Special Considerations and Pitfalls

• Failing to recognize pupil-involving third nerve palsy as a potential neurosurgical emergency can have serious consequences 1
• Assuming microvascular etiology in pupil-sparing third nerve palsy without thorough evaluation can lead to missed diagnoses 1
• Missing myasthenia gravis due to variable presentation and potential seronegativity can occur if ice test and single-fiber EMG are not considered 1
• Distinguish true ptosis from pseudoptosis caused by globe dystopia, globe asymmetry, ocular misalignment, or retraction of the contralateral lid 5

Additional Testing Based on Initial Findings

• For suspected neurological causes, consider:

  • MRI brain and orbits with and without contrast 1, 4
  • Blood tests for myasthenia gravis and other autoimmune conditions 4, 2
  • CT scans of brain, orbita, and thorax if indicated 2

• For suspected mechanical causes:

  • Detailed slit-lamp examination 6
  • Evaluation for floppy eyelid syndrome, which presents with upper eyelid edema and upper eyelid that is easily everted 6