Graves’ disease is an autoimmune disorder that affects the thyroid, eyes, and skin. Graves’ disease often leads to hyperthyroidism, where the thyroid gland produces an excessive number of thyroid hormones. In some cases, it can also cause hypothyroidism, where the thyroid gland fails to produce enough hormones.
Thyroid Eye Disease (TED), also known as Graves ophthalmopathy, is a condition that causes inflammation and damage to the tissues of the eye, including the muscles. It is closely related to Graves’ disease.
TED has two phases: The active or inflammatory phase and the stable phase.
The active phase can last for months up to three years, during which there is ongoing inflammation and tissue damage.
A stable phase follows when the inflammatory process subsides.
Who is Affected by Thyroid Eye Disease?
TED predominantly affects women more than men, with an incidence rate of 16 per 100,000 people in women and 2.9 per 100,000 in males. The median age of diagnosis for TED is 43 years old.
Risk Factor
Several factors that contribute to the risk of developing thyroid eye disease are gender (females being more affected than males), smoking, age (typically around 43 years old), and having an autoimmune predisposition. Certain genetic markers, such as HLA-DRS and HLA-B8, have also been associated with an increased risk.
Pathogenesis
It involves an autoimmune response targeted at orbital fibroblasts, with secondary involvement of the extraocular muscles. The specific antigen triggering the immune response is likely shared between the thyroid follicular cells and orbital fibroblasts. T-cells are believed to stimulate adipogenesis, fibroblast proliferation, and glycosaminoglycan synthesis within the orbit, leading to oedema, infiltration, and enlargement of the extraocular muscles.
What Are the Signs and Symptoms of Thyroid Eye Disease?
Symptoms of TED can vary but commonly include:
- Dry eyes
- Irritation and a gritty feeling in the eyes
- Excessive tearing
- Redness of the eyes
- Bulging eyes (proptosis)
- A staring appearance
- Double vision (diplopia)
- Difficulty closing the eyes completely, which can lead to corneal ulcers.
- Changes in vision
- Pain behind the eyes and discomfort with eye movements
Symptoms usually affect both eyes, although sometimes they may be more pronounced in one eye.
Typical ocular signs observed in TED include:
- Lid retraction
- Lid lag
- Proptosis (bulging eyes)
- Endocrine exophthalmos
- Malignant exophthalmos
- Dysthyroid ophthalmology
- Ocular Graves' disease
- Thyroid-associated ophthalmology
Investigation
Diagnosis of thyroid eye disease typically involves the following investigations:
- Thyroid function tests to assess hormone levels.
- Thyroid autoantibody assay to detect specific antibodies associated with Graves' disease.
- Ultrasonography to evaluate the structure and inflammation in orbit.
Management
The management of TED involves a combination of lifestyle changes, medical treatments, and surgical interventions.
a) Lifestyle Changes
- Applying cool compresses to the eyes
- Wear sunglasses to protect the eyes from excessive sunlight and wind.
- Sleeping with the head elevated to reduce overnight eye swelling.
- Taping the eyelids closed during sleep to prevent corneal exposure.
- Using prism glasses to minimize double vision.
b) Medical Treatments
Medical treatments may include oral or intravenous steroids to reduce inflammation and immunosuppressive medications to modulate the immune response.
c) Surgical Interventions
Surgery may be necessary in cases where conservative measures fail to improve the condition. Surgical interventions for TED include:
- Extraocular muscle surgery to correct eye misalignment and double vision caused by muscle imbalance.
- Eyelid surgery to correct lid retraction, lid lag, or to improve the appearance of the eyelids.
- Orbital decompression surgery to create more space within the orbit, relieving pressure on the optic nerve and reducing proptosis.
The choice of surgical procedure depends on the specific symptoms and their severity, as well as the individual patient's needs and goals.
It's important for individuals with thyroid eye disease to work closely with a multidisciplinary team of healthcare professionals, including endocrinologists, optometrists, ophthalmologists, and possibly surgeons, to ensure comprehensive and personalized management.
Conclusion
Thyroid eye disease is an autoimmune condition characterized by inflammation and damage to the tissues of the eye. It is often associated with Graves' disease and predominantly affects women.
TED has active and stable phases, with various ocular manifestations. Early diagnosis and a comprehensive management approach involving lifestyle changes, medical treatments, and surgical interventions can help alleviate symptoms and prevent long-term complications.
Regular follow-up with healthcare professionals specializing in thyroid eye disease is crucial for optimal management and improved quality of life for individuals with this condition.