Thyroid eye disease (TED), also known as Graves’ ophthalmopathy, is an autoimmune disorder often caused by thyroid dysfunction. People with thyroid eye disease may experience diplopia (double vision), proptosis (bulging eyes) and/or strabismus (misalignment of the eyes). Management of TED symptoms requires a multi-disciplinary approach to eye care. For example, someone seeing double as a result of TED may be referred to a neuro-ophthalmologist. Alternatively, a patient who notices their eye(s) drifting inward or outward because of TED may be referred to a strabismus surgeon. We asked Wilmer Eye Institute, Johns Hopkins Medicine experts Andrew Carey and Edward Kuwera 10 questions about TED, including what patients can expect during an exam and how different symptoms may be treated.
Andrew R. Carey, M.D.
Assistant Professor of Ophthalmology
Neuro-Ophthalmology, Medical & Genetic Retinal Disease
1. As a neuro-ophthalmologist, what are the signs you look for when first examining people with thyroid eye disease?
The earliest signs are dry eyes and red eyes, followed by eyelid retraction, often described as ‘stare,’ and proptosis, in which the eyes bulge forward. More severe signs are restricted eye movements and lagophthalmos, in which patients cannot fully close their eyes. The most severe cases have reduced visual acuity and an abnormal pupillary response that may indicate optic nerve damage.
2. What diagnostic tools are used to confirm diagnosis, understand severity and devise a treatment plan?
While most patients present with a history of thyroid dysfunction, orbital imaging can be useful for ruling out other causes of orbital inflammation and tumors. The most sensitive tests are blood tests for thyroid antibodies. Other tests that are very helpful for monitoring vision loss are color vision and visual field tests.
I find the clinical activity score, which is a composite of signs and symptoms (such as spontaneous pain, pain on eye movement) is very helpful for staging disease severity and monitoring progression. Patients with mild symptoms are often treated conservatively with a low-salt diet, artificial tears, a selenium supplement, sleeping with the head elevated, and a cold compress or a frozen sleep mask. Patients with more moderate to severe disease may benefit from more aggressive therapies such as radiation, steroids or other medications. Patients with sudden or rapid vision loss often need urgent surgery. While most patients remain stable, some may worsen. Those at highest risk are active smokers, therefore tobacco cessation counseling is crucial.
3. What is the difference between Graves’ disease and hyperthyroidism?
Graves’ disease is the most common cause of hyperthyroidism (an overactive thyroid gland), and it most commonly presents along with hyperthyroidism. However, Graves’ disease can present with hypothyroidism (underactive thyroid gland), or with alternating hyperthyroidism and hypothyroidism. Even in a normally functioning thyroid gland, patients may later develop thyroid dysfunction. Controlling hyperthyroidism helps to reduce the risk of thyroid eye disease development and worsening.
4. How is double vision treated in people with thyroid eye disease?
There are different severities of double vision from thyroid eye disease. Some people have transient double vision lasting seconds when moving their eyes; some have double vision only in extreme gaze (looking far left or right, or far up or down)—often described as ‘positional.’ The most severe kind is double vision when looking straight ahead. Transient and positional double vision may improve by controlling thyroid hormones, among other measures. If caught within the first three to six months, more severe positional and constant double vision may respond to treatment with radiation, steroids or other medications; however, if they are chronic, these conditions require surgery on the eye muscles to help straighten the eyes.
5. Can vision loss be restored in people with thyroid eye disease?
If diagnosed and treated in a timely manner, patients can have full recovery of vision loss. That's why it is so important for patients with Graves’ disease to see an eye doctor early in the disease stage, so we can diagnose and treat them early.
Edward Kuwera, M.D.
Associate Fellowship Program Director — Pediatric Ophthalmology and Adult Strabismus
Assistant Professor of Ophthalmology
6. What are the signs you look for when first examining people who might have thyroid eye disease?
When examining a patient for thyroid eye disease, I look for things such as strabismus; lid retraction (meaning you can see the whites of the eyes below the upper eyelid, or above the lower eyelid); proptosis; and signs of orbital congestion such as hyperemia (redness) and chemosis (swelling) of the conjunctiva. The medial rectus and inferior rectus are the most commonly involved extraocular muscles, frequently pulling the patient's eye down and in toward the nose.
7. What are common thyroid eye disease symptoms that patients discuss with you?
Patients usually see me specifically for double vision, or diplopia, as a result of a misalignment of the eyes. They frequently complain of coexisting dry eye from the proptosis and lid retraction. They may also complain of changes in vision and color vision, along with pain and general discomfort of the eyes.
8. Why does thyroid eye disease cause bulging, or “bug” eyes?
Thyroid eye disease causes soft tissue and extraocular muscle swelling in the orbit. This is a result of antibodies directed against thyroid receptors that happen to be present in orbital tissue. Subsequently, these tissues become infiltrated with glycosaminoglycans, which are chemical compounds mostly found in connective tissue. They swell and become scarred. As they swell, the eyes start to bulge, and as the muscles scar, they tighten and pull the eyes into their field of action (gazes of eye movement corresponding with the six extraocular muscles).
9. What other diagnostic tools are used to confirm diagnosis, understand severity and devise a treatment plan?
Orbital imaging is frequently performed to evaluate for changes in the extraocular muscles, along with any signs of optic nerve compression. We follow thyroid blood levels and strabismus measurements for at least one year, looking for stability prior to any surgical intervention.
Here at Wilmer Eye Institute, we also employ a diagnostic exam called the Lancaster red-green test. This test allows us to evaluate misalignment of the eyes in all directions of gaze, with the added benefit of understanding the torsional status (or twisting) of the eyes. This test, and the use of adjustable sutures during surgery, help our treatments to be more precise.
If the patient has too much swelling in the orbit, it may compress the optic nerve and cause loss of vision and/or color vision. This is monitored with tests for color vision, imaging of the optic nerve, and repeated visual field testing. Should optic neuropathy develop, orbital decompression surgery may be necessary.
Lastly, eyelid surgery may be needed to prevent exposure keratopathy (severe dry eye).
10. Aside from surgical intervention, what other treatments are there for people with thyroid eye disease?
For non-surgical strabismus options, we typically treat patients with frequent eye lubrication for dryness, along with prism and/or occlusion therapy for double vision. This is a process in which one eye is patched for a time, allowing the affected eye to become stronger and more useful. Prism glasses help to align images such that the patient can comfortably see a single image. We generally wait to observe at least one year of stability as indicated by blood tests and strabismus measurements before considering any surgical intervention.
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