Laboratory Studies
Screening for abnormal thyroid function commonly includes T4 and thyroid-stimulating hormone (TSH) tests. Results of these serum tests are abnormal in 90% of patients with TED. However, if the results are normal but thyroid disease is still strongly suspected, additional endocrine studies such as thyroid-stimulating immunoglobulins or TSH-receptor antibodies can be considered, as these tests have greater sensitivity for detecting thyroid disease.
Granulomatosis with polyangiitis (formerly called Wegener granulomatosis; see Chapter 4 in this volume) should be considered in patients with sclerokeratitis or coexisting sinus disease and orbital mass lesions. A useful test for this uncommon disease is the antineutrophil cytoplasmic autoantibody (ANCA) serum assay, which shows a cytoplasmic staining pattern (c-ANCA) in cases of granulomatosis with polyangiitis. However, the test results may initially be negative in cases of localized disease. Biopsy of affected tissues classically shows vasculitis, granulomatous inflammation, and tissue necrosis, although necrotizing vasculitis is not always present in orbital biopsies.
Testing for serum angiotensin-converting enzyme (ACE) and lysozyme may be helpful in the diagnosis of sarcoidosis. This multisystem granulomatous inflammatory condition may present with lacrimal gland enlargement, conjunctival granulomas, extraocular muscle or optic nerve infiltration, or solitary orbital granulomas. Diagnosis is confirmed through biopsy of one or more affected organs.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.