Características clínicas e diagnóstico da doença ocular da tireoide

Abstract

Introduction: Thyroid eye disease (also called Graves' orbitopathy or ophthalmopathy) is an autoimmune disease of the retroocular tissues that occurs in patients with Graves' disease and less commonly in patients with Hashimoto's thyroiditis. Untreated thyroid eye disease typically follows a course of progression at varying rates, followed by a plateau or stabilization, and then varying degrees of improvement. The inflammatory manifestations of the disorder (including ocular irritation and conjunctival and periorbital edema) tend to subside, while proptosis (exophthalmos) and extraocular eye muscle dysfunction persist. Objectives: discuss the clinical characteristics and diagnosis of thyroid eye disease. Methodology: Integrative literature review based on scientific databases from Scielo, PubMed and VHL, from January to April 2024, with the descriptors “Clinical characteristics”, “Diagnosis”, “Eye Disease” AND “Thyroid”. Articles from 2019-2024 were included (total 50), excluding other criteria and choosing 5 full articles. Results and Discussion: The main autoantigen in thyroid eye disease is the thyroid-stimulating hormone (TSH) receptor, which is expressed on orbital fibroblasts and forms a functional complex with the insulin-like growth factor 1 (IGF-1) receptor. ). Stimulation of TSH receptor antibodies and activated T cells plays an important role in the pathogenesis of thyroid eye disease by activating orbital fibroblasts and adipocytes. The volume of extraocular muscles and orbital connective and adipose tissue is increased, due to inflammation, adipogenesis and the accumulation of hydrophilic glycosaminoglycans (GAG; mainly hyaluronic acid) in these tissues. GAG secretion by fibroblasts is increased by cytokines from activated T cells and by activation of receptors for TSH and IGF-1. Thyroid eye diseases, such as hyperthyroidism, are more common in women than men. Risk factors for developing thyroid eye disease include smoking, prior radioiodine therapy, and possibly high serum cholesterol. The main eye symptoms include one or more of the following: a feeling of irritation in the eyes; excessive tearing that often worsens with exposure to cold air, wind, or bright lights; ocular or retro-ocular discomfort or pain; blurred vision; diplopia; and, occasionally, vision loss. The characteristic signs of thyroid eye disease are proptosis, periorbital edema, and extraocular muscle dysfunction (dysconjugate gaze). These findings often occur in the context of current or past Graves' hyperthyroidism (low TSH, high free thyroxine [T4], and/or triiodothyronine [T3]. In most patients, the diagnosis of thyroid eye disease is obvious due to the combination of characteristic ocular abnormalities (proptosis, periorbital edema). If thyroid tests are not available, dose TSH, free T4, total T3, and TSH (thyrotropin) receptor antibodies (TRAbs). Classification of disease severity (mild, moderate, severe, vision threatening) and activity is based on elements of the ocular examination. A multidisciplinary approach is recommended with early consultation and co-management with ophthalmology in all patients with moderate-severe disease. Conclusion: Clinically apparent thyroid eye disease occurs in 20 to 25 percent of patients with Graves' disease, most of whom have mild disease. In moderate to severe disease, noncontrast CT or MRI images can provide an assessment of the risk of future compression of the optic nerve by the enlarged extraocular muscle at the orbital apex and are sometimes helpful in the differential diagnosis.