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OCULAR MANIFESTATIONS OF THYROID DISEASE Graves ophthalmopathy Other names: thyroid eye disease, thyroid orbitopathy Autoimmune inflammatory disorder whose underlying cause continues to be elucidated Signs and symptoms may progress and abate independently of other clinical features Eye findings may occur even in the absence of objective evidence of thyroid dysfunction (euthyroid Graves disease) Graves ophthalmopathy o Ophthalmopathy may relate to antibodies that cross-react with TSH-R antigens expressed on orbital fibroblasts PATHOGENESIS: Theories: Glycosaminoglycans expressed from fibroblasts causes secondary water retention and therefore, retrobulbar swelling TSH-R as the antigen Fusiform enlargement of extraocular muscles; sparing of tendons Little enlargement of extraocular muscles but marked increased in the orbital fat may occur. Diagnostic criteria for Graves ophthalmopathy Key points about Grave’s disease: Most common cause of eyelid retraction Most common cause of bilateral or unilateral proptosis. More common in women Associated with hyperthyroidism in 90% of patients; 6% are euthyroid Smoking is associated with increased risk and severity of ophthalmopathy. The course of ophthalmopathy does not necessarily parallel the activity of the thyroid gland or the treatment of thyroid abnormalities. Grave’s disease/Thyroid Ophthalmopathy Clinical signs Eyelid retractionmost common sign Lid lag Proptosis Restrictive extraocular myopathy Optic neuropathy Other clinical features: Most frequent ocular symptom is pain or discomfort (30%)- often the result of dry eyes Diplopia- 17% Lacrimation/photophobia- 15-20% Blurring of vision- 7.5% Non-ocular clinical findings: Thyroid dermopathy- 4% Thryroid acropachy-1% Myasthenia gravis- 1% A. Bilateral proptosis and upper eyelid retraction B. Marked chemosis, eyelid swelling and increased proptosis • Bilateral lid retraction • No associated proptosis • Bilateral lid retraction • Bilateral proptosis • Unilateral lid retraction • Unilateral proptosis • Lid lag in downgaze Soft tissue involvement Periorbital and lid swelling Chemosis Conjunctival hyperaemia Superior limbic keratoconjunctivitis Proptosis • Occurs in about 60% • Uninfluenced by treatment of hyperthyroidism Axial and permanent in about 70% May be associated with choroidal folds Treatment options • Systemic steroids • Radiotherapy • Surgical decompression Optic neuropathy • Occurs in about 6% • Early defective colour vision • Usually normal disc appearance Caused by optic nerve compression at Often occurs in absence of significant orbital apex by enlarged recti proptosis Restrictive myopathy • Occurs in about 40% • Due to fibrotic contracture Elevation defect - most common Depression defect -uncommon Abduction defect - less common Adduction defect - rare Treatment: Correction of thyroid function abnormality Anti-thyroid drugs Radio active iodine thyroidectomy Orbital decompression- to treat optic neuropathy, orbital congestion, advanced proptosis Topical ocular lubricants Corticosteroid treatment Orbital radiotherapy- targets lymphocytes? Treatment and Prognosis: Self limiting, but…. may run an active course of exacerbation and remissions Therapy directed toward decreasing orbital congestion and inflammation or expanding the bony volume Treatment and Prognosis: Often improves with establishment of euthyroid state, but eye disease may continue to progress Elective orbital decompression, strabismus surgery and eyelid retraction repair usually are not considered until a ophthalmic signs have been stable for 6-9 months.