Orbital amyloidosis.

A 51-year-old male presented with a chronic asymmetrical ptosis which was variable. Repeated anticholinesterase testing gave equivocal responses. The patient was treated for myasthenia gravis until a mass was detected in the orbit. Although rare, localized orbital amyloidosis should be considered in the diagnosis of patients with ptosis, particularly when the results of anticholinesterase testing are equivocal.