[The pathological changes of the orbital tissue in thyroid associated ophthalmopathy].
To study the morphological representation of the orbital tissue in thyroid associated ophthalmopathy. It was a retrospective case series. 138 specimens of TAO (include 77 specimens of orbital fat, 41 specimens of orbital periosteum and 20 specimens of lacrimal gland tissue) were analyzed by light microscopy and immunohistochemical staining. The notable hyperplasia of fat was found in orbital tissue from 73 of 77 and in lacrimal gland tissue from 12 of 20. The hyperplasia of fibrous tissue and muscular metaplasia were observed in orbital periosteum. The hyperplasia of fat in TAO orbital and lacrimal gland tissue is a very important and ubiquitous pathological changes. Study on the orbital fat and prevent against the hyperplasia of fat maybe have a significance of effective to hold back proptosis.