The pathogenesis of thyroid-associated ophthalmopathy.

TAO is an autoimmune disease the pathogenesis of which is unclear. Autoimmunity against orbital antigens has been demonstrated, although the precise immunological mechanisms responsible are unidentified. Cytokines probably play an important mediating role. Activation of orbital fibroblasts appears to be essential in bringing about interstitial oedema and enlargement of EOM. The challenge for the future lies in clarifying the role of cytokines, identifying the autoantigen and elucidating the immunological mechanisms underlying the disease.