Understanding Thyroid Eye Disease (TED) and Treatment Goals
Thyroid Eye Disease (TED), also known as Graves' ophthalmopathy, is an autoimmune condition where the body's immune system mistakenly attacks the muscle and fat tissue behind the eyes [1.2.2, 1.3.3]. This attack causes inflammation and swelling, leading to symptoms like eye bulging (proptosis), double vision (diplopia), pain, redness, and in severe cases, pressure on the optic nerve that can threaten vision [1.2.2, 1.8.3]. The annual incidence rate in the United States has been reported as 16 per 100,000 women and 3 per 100,000 men [1.8.6]. The disease typically has an active inflammatory phase, which can last from 6 to 18 months, followed by an inactive, stable phase [1.3.6]. The primary goal of medication is to reduce inflammation, prevent long-term damage during the active phase, and alleviate symptoms like proptosis and diplopia [1.3.6].
The First FDA-Approved Medication: Tepezza (Teprotumumab)
Tepezza (teprotumumab-trbw) is the first and only medication specifically approved by the FDA to treat Thyroid Eye Disease, regardless of its activity or duration [1.2.5, 1.3.2]. It represents a significant advancement, as it targets the underlying mechanism of the disease, not just the symptoms [1.2.7].
How Tepezza Works
Tepezza is a monoclonal antibody that works by blocking the insulin-like growth factor-1 receptor (IGF-1R) [1.2.4]. This receptor is overexpressed in the tissues around the eyes of TED patients and plays a central role in the inflammation and tissue expansion that cause the disease's hallmark symptoms [1.3.7, 1.2.4]. By inhibiting this receptor, Tepezza reduces inflammation and prevents the tissue from expanding further behind the eyes [1.2.4].
Administration and Efficacy
Tepezza is administered as an intravenous (IV) infusion every three weeks, for a total of eight infusions over about five months [1.3.3]. The first dose is typically 10 mg/kg of body weight, with the remaining seven doses at 20 mg/kg [1.3.3]. Clinical studies have demonstrated its effectiveness, with one major trial showing that 83% of patients treated with Tepezza had a significant reduction in eye bulging compared to just 10% of patients on a placebo [1.3.7]. Improvements in double vision and overall quality of life were also significant [1.3.7]. Some patients begin to see a reduction in eye bulging in as few as six weeks [1.3.2].
Common Side Effects
The most common side effects associated with Tepezza include muscle spasms, nausea, hair loss, diarrhea, fatigue, high blood sugar (hyperglycemia), and hearing problems [1.6.2, 1.6.3]. Hearing issues can be severe and potentially permanent in some cases, so audiological monitoring may be recommended before, during, and after treatment [1.2.2, 1.6.2].
Traditional and Supportive Medications for TED
Before the approval of Tepezza, and still used today, several other medications have been employed to manage the symptoms of TED, primarily by controlling inflammation.
Corticosteroids
Corticosteroids, such as prednisone and methylprednisolone, are powerful anti-inflammatory drugs that have long been a mainstay of TED treatment, especially for moderate-to-severe active disease [1.4.2, 1.4.4]. They work by suppressing the body's overall immune response to decrease swelling and inflammation [1.4.4].
- Oral Steroids: Prednisone is often given in tablet form, with the dose gradually tapered over weeks or months [1.4.2].
- Intravenous (IV) Steroids: For more severe cases, high-dose IV methylprednisolone may be administered in "pulses," which can be more effective and have fewer side effects than long-term oral use [1.4.2, 1.3.6].
While effective at reducing inflammation, steroids do not reliably improve proptosis or diplopia and come with significant side effects, including weight gain, mood changes, high blood pressure, and bone density loss [1.4.1, 1.7.1].
Selenium Supplementation
For patients with mild TED, selenium supplements may be beneficial [1.5.3]. Selenium is a trace element with antioxidant properties that can help protect tissues from damage [1.5.5]. Studies have shown that a 6-month course of selenium (typically 100-200 mcg daily) can improve quality of life and slow the progression of mild TED [1.5.3, 1.5.4]. It is most beneficial in the early, active phase of the disease [1.4.1].
Other Immunomodulators (Off-Label Use)
In some cases, particularly when patients are resistant to steroids, doctors may prescribe other immunosuppressive drugs off-label. These include:
- Mycophenolate Mofetil (CellCept): This medication has been shown to be effective, sometimes in combination with corticosteroids, in treating GO [1.7.3, 1.7.4].
- Rituximab (Rituxan): A monoclonal antibody that targets B cells, it is considered an alternative or second-line treatment for TED [1.7.2, 1.7.4].
- Tocilizumab (Actemra): This drug is another biologic that may be considered as an alternative treatment [1.7.2].
These medications are not FDA-approved for TED and their use is based on smaller studies and clinical judgment [1.7.1].
Comparison of Common TED Medications
| Medication | Mechanism of Action | Administration | Best For | Key Side Effects |
|---|---|---|---|---|
| Tepezza (Teprotumumab) | Blocks IGF-1R to reduce inflammation and tissue expansion [1.2.4] | IV infusion every 3 weeks for 8 doses [1.3.3] | Moderate-to-severe TED, reducing proptosis and diplopia [1.4.5, 1.3.7] | Muscle spasms, hair loss, high blood sugar, hearing loss [1.6.2] |
| Corticosteroids (e.g., Prednisone) | Broadly suppresses the immune system and inflammation [1.4.4] | Oral pills or IV infusions [1.4.2] | Moderate-to-severe active inflammation [1.4.2] | Weight gain, mood changes, high blood pressure, bone density loss [1.4.1] |
| Selenium | Antioxidant, protects orbital tissues [1.4.1, 1.5.5] | Oral supplement (100-200 mcg daily) [1.5.4] | Mild, active TED [1.5.3] | Generally well-tolerated at recommended doses; high doses can be toxic [1.5.4] |
Conclusion
The treatment landscape for Thyroid Eye Disease has been revolutionized by the introduction of Tepezza (teprotumumab), the first FDA-approved medication that targets the underlying cause of the disease to reduce eye bulging and double vision [1.3.6]. While Tepezza is a primary option for moderate-to-severe cases, traditional treatments like corticosteroids remain crucial for managing acute inflammation [1.4.4]. For milder forms of the disease, selenium supplements offer a supportive option to slow progression and improve quality of life [1.5.3]. The choice of medication depends on the severity and activity of the disease, and treatment should always be guided by a specialist.
For more information from a leading authority, you can visit the American Thyroid Association.
