Purpose of review: To better understand the various causes of Brown's syndrome, provide a historical account of the progression of Brown's syndrome, and to bring attention to clinical characteristics specific to Brown's syndrome.
Recent findings: The inability to elevate an eye in adduction is a common problem with a number of possible causes usually pointing to cyclovertical muscle involvement. The specific cause can usually be determined by either the three-step test or forced ductions. Because Brown's syndrome does not involve a paretic cyclovertical muscle but rather a mechanical muscle limitation, forced ductions instead of the three-step test must be used to evaluate a patient of Brown's syndrome and is crucial in the diagnosis.
Summary: The recognition of true Brown's syndrome can be accomplished by clinical examination and confirming the diagnosis with a positive forced duction test.