 The inflammation results in a deposition of collagen and glycosaminoglycans in the muscles, which leads to subsequent enlargement and fibrosis.There is also an induction of the lipogenesis by fibroblasts and preadipocytes, which causes enlargement of the orbital fat and extra-ocular muscle compartments.This increase in volume of the intraorbital contents within the confines of the bony orbit may lead to dysthyroid optic neuropathy (DON), increased intraocular pressures, proptosis, and venous congestion leading to chemosis and periorbital oedema.