Laboratory Tests for Eye Twitching

Initial Assessment and Diagnostic Approach

• The American Academy of Ophthalmology recommends acetylcholine receptor antibody testing (AChR-Ab) for diagnosing myasthenia gravis in patients with eye twitching, as binding, blocking, or modulating antibodies can confirm the diagnosis 1
• The American Academy of Ophthalmology suggests anti-muscle-specific kinase antibody (anti-MuSK-Ab) testing for seronegative cases, as approximately one-third of AChR-negative patients will be MuSK-positive 1
• Lipoprotein-related protein 4 (LRP4) antibody testing is associated with both generalized and ocular myasthenia gravis, according to the American Academy of Ophthalmology 1
• About 50% of patients with ocular myasthenia are seronegative on standard antibody testing, as reported by the American Academy of Ophthalmology 1, 2

Thyroid Function Tests and Other Laboratory Evaluations

• The American Thyroid Association recommends antithyroid peroxidase antibody testing for suspected thyroid eye disease in patients with eye twitching 3
• The American Thyroid Association suggests antithyroglobulin antibody testing for suspected thyroid eye disease in patients with eye twitching 3
• Thyroid-stimulating hormone (TSH) testing is recommended by the American Thyroid Association to assess thyroid function in patients with eye twitching 3
• The American Academy of Ophthalmology recommends serum electrolyte testing to rule out metabolic disturbances, particularly magnesium, calcium, and potassium abnormalities, in patients with persistent eye twitching 3
• Complete blood count is recommended by the American Academy of Ophthalmology to assess for underlying systemic conditions in patients with eye twitching 3
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) testing is suggested by the American Academy of Ophthalmology if inflammatory conditions are suspected in patients with eye twitching 3

Electrophysiological Testing and Diagnostic Procedures

• Single-fiber electromyography (EMG) is considered the gold standard for diagnosing ocular myasthenia by the American Academy of Ophthalmology, with a positivity rate of over 90% 1, 2
• Repetitive nerve stimulation testing is recommended by the American Academy of Ophthalmology, though it is less sensitive, with a positivity rate of only one-third of ocular myasthenia cases 1
• The ice test is highly specific for myasthenia gravis and can help guide laboratory testing, according to the American Academy of Ophthalmology 1