Grave disease.(hyperthyroidisim)...c

In Graves ophthalmopathy the volume of the retro-orbital connective tissues and extra-ocular muscles is increased as a result of several causes

(1) marked infiltration of the retro-orbital space by mononuclear cells, predominantly T cells

(2) inflammatory edema and swelling of extra-ocular muscles;

(3) accumulation of extracellular matrix components, specifically hydrophilic glycosaminoglycans such as hyaluronic acid and chondroitin sulfate;

(4) increased numbers of adipocytes (fatty infiltration).