Is 20mg of methotrexate orally a good medicine for scleritis and how long does it take to work?

Yes: Methotrexate is a reasonable choice, especially if the scleritis cannot be controlled on reasonable doses of prednisone. Tnf agents would be another option as are other immunosuppressive such as azathioprine. The choice of therapy may be influenced by the presence of an underlying cause for the eye inflammation.

Depends: Scleritis can be caused by different problems since slceritis just means that your sclera are inflamed. If it's been determined to be an autoimmune condition, then Methotrexate may be helpful. However, low dose weekly Methotrexate injected under the skin is a much more effective way to take it (more medicine is absorbed and fewer side effects).Methotrexate usually takes 2-3 months to start working.