This is usually done using the accepted Myasthenia Gravis Foundation of America Clinical Classification scale. Physical examination
During a physical examination to check for MG, a doctor might ask the person to perform repetitive movements. For instance, the doctor may ask one to look at a fixed point for 30 seconds and to relax the muscles of the forehead, because a person with MG and ptosis of the eyes might be involuntarily using the forehead muscles to compensate for the weakness in the eyelids. The clinical examiner might also try to elicit the "curtain sign" in a person by holding one of the persons eyes open, which in the case of MG will lead the other eye to close. Blood tests
If the diagnosis is suspected, serology can be performed:

One test is for antibodies against the acetylcholine receptor; the test has a reasonable sensitivity of 80–96%, but in ocular myasthenia, the sensitivity falls to 50%. A proportion of the people without antibodies against the acetylcholine receptor have antibodies against the MuSK protein. In specific situations, testing is performed for Lambert-Eaton syndrome. Electrodiagnostics
Muscle fibers of people with MG are easily fatigued, which the repetitive nerve stimulation test can help diagnose. In single-fiber electromyography, which is considered to be the most sensitive (although not the most specific) test for MG, a thin needle electrode is inserted into different areas of a particular muscle to record the action potentials from several samplings of different individual muscle fibers.
Several generic companies challenged the validity of the patents and filed Abbreviated New Drug Applications (ANDA) seeking market entry. Allergan responded by filing a lawsuit against the ANDA filers. In Allergan, Inc. v. Sandoz, Inc., the US Court of Appeals for the Federal Circuit ruled that Allergans composition-related patent claims were invalid based on obviousness, because brimonidine and timolol had already been marketed in the claimed concentrations. However, Allergans method claim (US Patent No. 7,030,149), which states "reducing the number of daily topical ophthalmic doses of brimonidine administered topically to an eye of a person in need thereof for the treatment of glaucoma or ocular hypertension from 3 to 2 times a day without loss of efficacy", was held to be non-obvious. As a result, generic companies are prevented from marketing generic versions of Combigan until its patent expiration in 2022.Combigan is supplied in 5 mL, 10 mL, and 15 mL bottles. In the United States, the cash price of one 5-mL eye dropper of Combigan ranges from $160 to $190. == References ==