Thyroid Eye Disease (Overview)
What is Thyroid-Related Eye Disease or Graves' Ophthalmopathy?
Graves’ disease (toxic diffuse goiter) is an autoimmune disorder where the patient’s own immune system produces autoantibodies that attack the thyroid gland. Stimulation of the thyroid gland may then result in overproduction of thyroid hormones. In up to 10% of hyperthyroid patients, the tissues around the eye will also be involved due to a similar antibody attack on the extraocular muscles, fat, and connective tissue within the orbit. The constellation of eye findings that is seen in these patients is referred to as thyroid eye disease or more appropriately, thyroid-related eye disease.
In whom does Thyroid Eye Disease occur?
Clinically apparent thyroid ophthalmopathy (thyroid-related eye disease) occurs in up to 50% of patients with hyperthyroidism. Thyroid ophthalmopathy may accompany hypothyroidism, Hashimoto’s thyroiditis, and in some patients, occur in the absence of objective evidence of thyroid dysfunction (euthyroid Graves’ disease). Thyroid-related eye disease is four to six times more common in women than men and typically presents in middle-age but may occur in children and in the elderly. It may present prior to the diagnosis of thyroid dysfunction, at the same time (~20%), or several years later. For those patients that present initially with isolated eye disease, the risk of developing thyroid disease is about 25% within 1 year and 50% within 5 years. Risk factors for developing or exacerbating thyroid orbitopathy include smoking, older hyperthyroid males, and high initial serum T3 hormone levels. Several studies have documented an association between tobacco smoking and thyroid disease. Those with thyroid disease who smoke are more likely to have eye disease. Thyroid eye disease patients who smoke tend to have more severe eye disease than nonsmoking thyroid patients.
What is going on in the eye socket?
The same immune mediated process occurring in the thyroid gland is going on in the orbit. Autoantibodies (produced by B-lymphocytes) are directed at the extraocular muscles, fat, connective tissue and lacrimal gland. This interaction leads to deposition of hydrophilic (attract water) mucopolysaccharides and collagen leading to swelling, increase eye socket fat, and the“eye signs” described below.
What are the symptoms of thyroid-related eye problems?
Thyroid-related eye disease (TRED) is a bilateral condition but may be markedly asymmetric. In mild thyroid-related eye disease, patients may only be aware of dry, irritated eyes. The eyelids may swell giving a full appearance to the upper and lower eyelids. As the tissues of the orbit become involved, the eyes may bulge forward (proptosis or exophthalmos) and there may be aching behind the eye. Eyelid retraction is the most common eye sign of Graves' disease. The upper eyelids may retract upward and the lower eyelids may retract downward giving patients a characteristic “stare”. Eyelid retraction may vary and occasionally “flare” giving a more pronounced appearance of protruding eyes. Proptosis and eyelid retraction may result in poor corneal protection and inadequate eyelid closure. In severe cases, vision loss may result from corneal exposure and/or ulceration. Vision-threatening, painful, spontaneous globe subluxation (eyelids retract behind protruding globe) may occur in cases of advanced proptosis. Extraocular muscle involvement may lead to double vision. Vision loss may also occur if swelling of extraocular muscles and/or proptosis lead to optic nerve compromise (compression or stretch).
What is the natural course of Thyroid-Related Eye Disease?
It is important that patients follow the guidance of their primary care physician and endocrinologist to achieve a euthyroid state (normal thyroid levels) as quickly as possible. Once the thyroid problem has been adequately treated with antithyroid medications, radioactive iodine, and/or surgical removal of the thyroid, systemic symptoms typically resolve. Patients with significant eye disease may have worsening of their symptoms at the time of radioablation of the thyroid gland. Low dose systemic corticosteroids shortly before and up to 2 to 3 months following radioablation may minimize exacerbation of eye disease. Unfortunately, once patients achieve a normal thyroid status, the eye changes may not disappear and, in some cases, may still progress. Remember, the eye disease is only indirectly related to the thyroid dysfunction.
The inflammatory disease process in the eye region usually runs a course from 3 months to 3 years at which time it typically "burns out". The eye disease during this inflammatory phase may be mild or may be progressive and severe requiring medical and/or surgical intervention to prevent vision loss. Once the disease is believed to be quiescent ("burned out"), some of the eye signs may resolve but in a majority of patients some disfigurement (proptosis, eyelid retraction) remains. Patients with thyroid orbitopathy require regular oculoplastic evaluations (every 1 to 3 months) to monitor and treat the potentially devastating complications. Patients with orbital disease should also be followed closely by their general eye care provider to monitor for changes in vision, visual field, and intraocular pressure.
What treatment is available for Thyroid Eye Disease?
The optimal management of thyroid-related eye disease is still evolving. In general, two phases of eye treatment are considered. The initial phase involves treating the active, inflammatory disease and focuses on the preservation of eyesight. Patients should be followed closed by their ophthalmologist or general eye care provider to monitor for visual acuity changes, restriction in their visual field, or increased intraocular pressure. During this initial disease phase patients generally require treatment of Dry Eyes including artificial tear supplements (drops every 1 to 4 hours), lubricating eye ointment at bedtime, and occasionally taping the lids closed at night. If the inflammation is more pronounced, a brief course (10 days) of oral corticosteroids may be indicated. Occasionally, a more prolonged course (6 to 10 weeks) with a slow taper may be necessary. If the patient has a good response to oral corticosteroids but relapses with cessation or tapering, then orbital radiation therapy may be considered. If there is significant visual compromise that is unresponsive to corticosteroids, then urgent orbital decompression surgery should be considered to expand the eye socket.
All patients should be made aware of the role of tobacco smoking in exacerbating thyroid eye disease. Once the active phase has appeared to have run its course and the thyroid-related eye findings have stabilized, the patient is assessed for residual disfiguring changes. There are a number of reconstructive options available to help return the patient to a more comfortable and acceptable appearance.
What are the reconstructive surgeries available to the Thyroid-Related Eye Disease patient?
There are four main stages of surgical rehabilitation. Orbital decompression and eyelid surgery are unique procedures in the thyroid patient and should only be performed by an experienced ophthalmic plastic (oculoplastic) surgeon. Dr. Klapper has considerable experience performing orbital bone decompression surgery and reconstructive eyelid procedures.
1) Orbital decompression
This surgery is performed under general anesthetia and involves removal of bone and/or fat around the eye socket. The orbital tissues can then expand into the space created (usually the ethmoid and maxillary sinuses) diminishing the orbital pressure, limiting optic nerve compromise, and allowing the eye to move back to a more normal position. Orbital decompression has typically been used to treat optic neuropathy (vision loss), advanced proptosis, and globe subluxation. It is now often performed as an elective procedure under general anesthesia in patients with disfiguring proptosis or in patients with moderate to severe proptosis that may be considering extraocular muscle surgery (strabismus surgery). Risks and complications include: severe bleeding, infection, worsening of double vision, cerebrospinal fluid leak, and severe vision loss (rare). Dr. Klapper frequently works with otolaryngology colleagues (ENT) to provide patients with optimal multi-disciplinary surgical care.
2) Strabismus surgery (double vision)
If prism spectale therapy does not adequately relieve a patient’s significant double vision, then extraocular muscle surgery may be necessary. One or both eyes may require surgical adjustment of their muscles to improve the double vision, particularly in straight ahead and downgaze. If indicated, Dr. Klapper will assist in making arrangements with surgeons specializing in eye muscle surgery(strabismologists) to assist in this aspect of your comprehensive eye care.
3) Eyelid retraction repair
The upper eyelids can be lowered and the lower eyelids elevated. This surgery is performed in an outpatient setting, typically with monitored anesthesia and intravenous sedation for additional comfort. Patients are kept alert throughout the surgery so that intraoperative adjustments can be made to achieve the optimal upper eyelid position. If the lower eyelid retraction is severe, placement of a spacer material (such as ear cartilage) may be necessary to adequately correct the lower eyelid malposition. Potential expectations include temporary eye irritation, changes in eyelid contour, palpable spacer material, bruising, occasionally the need for touch-up surgeries if over or undercorrection of the eyelid height occurs. Risk and complications may rarely include wound dehiscence, infection, or vision loss.
The last surgical stage is sometimes referred to as the “touch-up stage” to improve the overall appearance and feel of the eyelids. Excess skin is removed along with sculpting of the protruding fat to decrease the fullness of the eyelids. Blepharoplasty Surgery is performed under monitored anesthesia and intravenous sedation.
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