This patient presents with Grave’s ophthalmopathy. Grave's ophthalmopathy occurs secondary to an autoimmune process which leads to extraocular muscle inflammation and orbital congestion. Thyroid ophthalmopathy, also know as Grave’s ophthalmopathy, is thought to be an antibody-mediated reaction against the TSH receptor with t-cell lymphocytes migrating to the orbit where they react with similar antigenic epitopes located in the retroorbital space, creating inflammation The resulting immune response results in enlargement of extraocular muscles with sparing of the muscle tendons, and orbital congestion which accounts for most of the clinical findings in Grave's ophthalmopathy. Orbital changes are not a direct effect of thyroid stimulating immunoglobins which cause the thyroid disturbances, but these molecules are found in 50% of patients. Patients with thyroid ophthalmopathy do not always have active thyroid disease.
Symptoms may include upper and lower eyelid retraction, dry eyes, double vision, eye muscle weakness, excessive tearing, and eye irritation. Exam findings may show exophthalmos proptosis (forward movement of the globe), lagophthalmos (inability to close eyes), strabismus (misalignment of eyes) swelling of the eyelids, scleral show, corneal dryness, chemosis of the conjunctiva, increased intraocular pressure, and, in extreme cases, reduced vision.
Other differential diagnoses to consider include orbital tumors (primary or metastatic), other causes of orbital inflammation (pseudotumor, Wegener's, myositis), and infection (cellulitis).
Work up of Grave’s ophthalmopathy includes a non-contrast orbital CT which will often show bilateral extraocular muscle(EOM) enlargement with sparing of tendons. An ultrasound may show enlarged EOM on B-scan. Other work-up can include TSH, and free T3, T4 levels.
Treatment of Grave’s ophthalmopathy is independent of systemic disease. The aim is to conserve vision. Artificial tears can be used for corneal exposure. Eyelid surgery can be considered for severe lid retraction. High dose glucocorticoids are used for optic neuropathy and can be combined with immunosuppressants (ciclosporin, azathioprine, cyclophosphamide). Sometimes, surgical decompression of the orbit is needed. If patients develop diplopia secondary to strabismus, prisms can be used and muscle reconstruction can also help. Finally, decompression maybe indicated if medical therapy fails and vision is threatened.
Most cases of grave’s ophthalmopathy stabilize or regress within 8-36 months.