Extraocular Muscle Thickening on Imaging
Thyroid orbitopathy (often spares tendon), idiopathic orbital inflammatory syndrome (involves tendon).
Tumor (e.g., lymphoma, metastasis, or spread of lacrimal gland tumor to muscle), c-c fistula, superior ophthalmic vein thrombosis, cavernous hemangioma (usually appears in the muscle cone without muscle thickening), rhabdomyosarcoma (children).
See 7.6, Lacrimal Gland Mass/Chronic Dacryoadenitis.
Optic nerve glioma (especially children), optic nerve meningioma (especially adults).
Metastasis, leukemia, idiopathic orbital inflammatory syndrome, sarcoidosis, increased intracranial pressure with secondary optic nerve swelling.
See 7.1, Orbital Disease.