CURRENT AND FUTURE TRENDS IN THE MANAGEMENT OF THYROID — AGRAWAL AND MEHTA 25
Current Topic
sparing of the tendons and an increase in fibro-adipose tissue (Fig 2). In patients with optic neuropathy there may be compression of the optic nerve by the enlarged extraocular muscles especially at the apex(apical crowding) .
Current and future trends in the management of thyroid associated ophthalmopathy
Treatment :
Thyroid dysfunction should be corrected in all patients.Thyroid dysfunction may be treated with antithyroid drugs or with radio-iodine Activity and Staging : therapy. In randomised trials, radioThe clinical activity score helps in iodine therapy for Graves’ classifying TAO as active or inactive . hyperthyroidism caused progression Components of the clinical activity of ophthalmopathy in about 15% of score are spontaneous retrobulbar patients, whereas antithyroid drugs pain, pain with eye movement, redness did not modify the natural course of of the eyelids, redness of the conjunctiva, swelling of the eyelids, G r a v e s ’ o p h t h a l m o p a t h y. swelling of the caruncle, conjunctival Prophylactic treatment with glucooedema (chemosis). Each component Fig 1 — Showing Bilateral Exophthalmos and corticoid agents may be appropriate is given a score of 1. A total score of 0-2 Marked Retraction of the Upper Eyelid for many patients with Graves’ indicates inactive throid associated ophthalmopathy whose hyperophthalmopathy while a score from 3thyroidism has been treated with 7 indicates active Graves' ophthalradio-iodine therapy especially those mopathy . with high risk factors. Risk factors for Patients with active disease will progression of Graves’ ophthalshow a good response to immunomopathy after radio-iodine therapy suppressive therapy while those with inactive disease will not. include cigarette smoking, severe In addition TAO has been hyperthyroidism (serum triclassified as mild, moderate or severe iodothyronine concentration,>5 nmol (Table 1) . Dysthyroid optic per liter), high levels of thyrotropin2 — CECT Scan (Axial Section) Showing neuropathy and keratopathy both Fig Exophthalmos and Enlarged Medial Rectus receptor antibodies, and uncontrolled indicate that the ophthamopathy is and Inferior Rectus Muscles hypothyroidism after radio-iodine sight threatening and should be treated therapy. immediately. Any risk factor for the progression of ophthalmopathy Another method of classification developed in Vancouver is the VISA classification . This is a clinical if present should be controlled. Smoking (if present) recording form which separates the clinical features of should be stopped.Any concurrent infections should be thyroid ophthalmopathy into the following four treated.The treatment of ophthalmopathy includes p a r a m e t e r s : V ( v i s i o n , o p t i c n e u r o p a t h y ) ; I supportive treatment, glucocorticoids, other (inflammation,congestion); S (strabismus,motility immunosuppressive agents, orbital radiotherapy, surgery. restriction); A (appearance, exposure). International Supportive therapy : This includes lubrication with Thyroid Eye Disease Society has modified these recording forms by consensus of its members and adopted them as topical tear supplements and non-steroidal antiinflammatory drugs, dark glasses and taping of the eyelids their standardised office record . at night to reduce the symptoms of dry eye. Prism glasses are used for the correction of diplopia.Mild Table 1 — Showing Features of Mild and Moderate to Severe Graves’ Ophthalmopathy ophthalmopathy may be treated with local measures alone Characteristic Mild Graves’ Moderate to severe with follow-up every 3 to 6 months as there is a 25% ophthalmopathy Graves' ophthalmopathy chance of it progressing to moderate to severe grade . Eyelid retraction (mm) <2 >2 Glucocorticoids : Vision threatening optic Exophthalmos (mm) <3 >3 Soft tissue involvement Mild Moderate-to-severe neuropathy requires treatment with glucocorticoids.The Extra-ocular muscle None or intermittent Inconstant or constant usual regimen is to give methylprednisolone in a dose of involvement (diplopia)* Corneal involvement Absent or mild Moderate one gram intravenously for initial three days.This is followed by oral corticosteroids.If there is no *Intermittent diplopia occurs when the patient is fatigued or improvement after one to two weeks the patient should awakening in the morning. Inconstant diplopia occurs at extremes of gaze.Constant diplopia occurs both when the patient is looking undergo prompt surgical decompression . 1
Garima Agrawal1, D C Mehta2
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Thyroid associated ophthalmopathy is common in patients with thyroid dysfunction. The present article reviews the current and future concepts in the management of thyroid associated ophthalmopathy. Many of the guidelines in the present article are based on the consensus statement of the European Group on Grave’s Orbitopathy. The present article was written after reviewing the articles on the net and journals as mentioned in the references. [J Indian Med Assoc 2016; 114: 24-7]
Key words : Thyroid associated ophthalmopathy, management.
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whereas older patients, more than seventy years old, can develop severe, isolated muscle enlargement associated with compressive optic neuropathy . The shared auto-antigen may be the thyrotropin receptor or the insulin like growth factor 1 receptor. B cells act as antigen presenting cells and autoantibody producing cells. Genetic factors in Graves' ophthalmopathy remain poorly understood.Environmental factors play a major role in the development and progression of the ophthalmopathy. These include smoking as an important risk factor. Microbial infections have also been postulated as a risk factor .
cular involvement is common in patients with thyroid disease. In these patients the status of the thyroid is variable. The majority are hyperthyroid, some are hypothyroid while a few are euthyroid.In many it may be difficult to demonstrate any thyroid abnormality at all. Thus the management of the thyroid dysfunction and the threat to vision requires close co-operation between the ophthalmologist and the physician/endocrinologist. The present article reviews the current and future trends in the management of thyroid associated ophthalmopathy.
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The present article was written after reviewing articles on the internet and the journals as mentioned in the references.It was kept in mind to include the recent studies and updates on the subject .The authors experience in treating patients of Thyroid associated ophthalmopathy (TAO) in the clinics was invaluable in writing the article.
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Clinical Features : The clinical features include lid retraction,lid lag,proptosis, extra-ocular muscle involvement, optic neuropathy, conjunctival congestion and chemosis (Fig 1). The natural course of thyroid ophthalmopathy is variable.Usually there is an active phase that lasts for onetwo years followed by a plateau phase when the disease becomes stable and finally the inactive phase when there is remission.The remission is generally incomplete .
Pathogenesis : TAO is initiated by autoreactive Tcells that react with one or more antigens shared by the thyroid and the orbit.These T lymphocytes after reaching the orbit react with the shared auto-antigen and trigger a cascade of events.There is secretion of cytokines which cause proliferation of fibroblasts, expansion of adipose tissue and secretion of hydrophilic glycosaminoglycans from the fibroblasts.There is a resultant increase in orbital content which explains many features of the ophthalmopathy .
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Diagnosis and Investigations : The diagnosis is certain in patients with bilateral ophthalmopathy and thyroid dysfunction. Thyroid dysfunction is evident by serum levels of T3,T4 and TSH. In those with doubt orbital imaging and measurement of thyrotropin receptor antibodies is warranted. Presence of high levels of serum thyrotropin receptor antibodies are highly specific and sensitive for thyroid associated ophthalmopathy. Orbital imaging with CT scan or MRI will reveal enlargement of the extra-ocular muscles with
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Those individuals younger than forty years are considerably more likely to manifest orbital fat expansion related proptosis in the absence of muscle infiltration, M & J Institute of Ophthalmology, BJ Medical College, Ahmedabad 380016 MS (Ophthalmol), Assistant Professor MS (Ophthalmol), Professor and Director 1
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straight ahead and when the patient is looking down
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