The thyroid is a small gland in the front of the neck that secretes hormones. Thyroid diseases cause the gland to produce too much or too little of these hormones. These diseases cause a range of symptoms, some of which affect the eyes. Doctors refer to this as “thyroid eye disease” (TED).
Dry eye is a condition in which the eyes do not make enough tears or the tears evaporate too quickly. This can result in symptoms such as eye pain, blurred vision, and sensitivity to light.
This article outlines the link between thyroid diseases and dry eye and describes some of the first signs of TED. We also list some different types of thyroid diseases and their risk factors. Finally, we discuss some home remedies and other treatments for dry eye due to TED.
Thyroid diseases can cause a variety of symptoms, some of which may affect the eyes.
Scientists and medical professionals do not fully understand the mechanism through which thyroid disease may affect the eyes. However, it seems that people with thyroid disease have an
- fewer nerve fibers within the cornea, which is the clear layer that protects the iris and lens and focuses light onto the retina at the back of the eye
- reduced sensitivity in the cornea
- reduced tear production and rapid tear evaporation, both of which may contribute to dry eye
- bulging of the eyes, which can also contribute to dry eye
Further studies are necessary to better understand how thyroid diseases may cause or contribute to dry eye.
Some of the most common signs and
- eyelid swelling
- eye pain
- excessive tears
- blurred vision
- double vision
- photophobia, which is sensitivity to light
If a person has a diagnosis of thyroid issues and experiences any of the above eye symptoms, they should contact their doctor or make an appointment with an eye doctor, or “ophthalmologist.” Doctors will work to diagnose the eye condition and provide appropriate treatments.
There are three levels of thyroid gland functions: euthyroid, hyperthyroid, and hypothyroid. Euthyroid gland function means that a person’s thyroid functions normally, hyperthyroidism is when the thyroid gland produces too many hormones, and hypothyroidism is when it makes too little.
Other diseases may cause or contribute to thyroid disease. These include Graves’ disease (GD) and Hashimoto’s disease (HD).
Hyperthyroidism is the medical term for an
Symptoms associated with hyperthyroidism include:
- heart palpitations
- heat intolerance
- weight loss
- sleep disturbances
Hypothyroidism is the medical term for an underactive thyroid gland, meaning the thyroid does not produce enough thyroxine and triiodothyronine.
- weight gain
- cold intolerance
- dry skin
- changes to the voice
GD is an autoimmune condition that can cause hyperthyroidism. In GD, antibodies stimulate the thyroid gland to produce too much thyroid hormone.
- rapid heart rate
- irregular heartbeat
- muscle weakness
- irregular periods in females
- frequent bowel movements
- weight loss
- hair loss
HD is an autoimmune disease that causes hypothyroidism. In HD, the immune system attacks the thyroid gland, causing it to swell. This may result in a lump or “goiter” in the throat.
- slow heart rate
- high blood pressure
- weight gain
- abnormally heavy or prolonged periods in females
- dry skin
- brittle nails
- facial swelling
- decreased sweating
- cold intolerance
- peripheral neuropathy
- muscle cramps
- joint pain
- hair loss
- sleep apnea
- memory loss
Certain factors can increase a person’s risk of developing thyroid diseases. We outline these below.
Risk factors for hyperthyroidism
Factors that can increase a person’s risk of developing hyperthyroidism include:
- Graves’ disease
- excessive iodine intake
- high levels of the hormone human chorionic gonadotrophin in the body, which may occur during early pregnancy, or in cases of multiple pregnancies
- thyroiditis, which is inflammation of the thyroid gland
- pituitary adenoma, which is a benign tumor of the pituitary gland
- thyroid cancer
Risk factors for hypothyroidism
Factors that can increase a person’s risk of developing hypothyroidism include:
- Hashimoto’s disease
- previous thyroid treatments, such as surgery or radioactive iodine therapy
- lack of dietary iodine
- Problems with the pituitary gland
- use of certain medications, such as:
- lithium, which doctors may prescribe for depression or bipolar disorder
- amiodarone, which people may take to treat an irregular heartbeat
- interferons, which people may take to treat hepatitis C or certain types of cancer
In many cases of TED, treating thyroid disorder will not alleviate the dry eye. As such, a person will require additional treatment to manage dry eye and associated symptoms.
A doctor will typically recommend a multistep approach to treatment, depending on the severity of the dry eye.
Primary treatment options typically include changes to the environment, such as:
- eliminating exposure to direct airflow or fans
- using humidifiers in the home
- wearing sunglasses outdoors
- reducing screen time
Secondary treatment options typically include medications to treat the dry eye and any associated conditions. Medications may
- eye drops
- ocular lubricants
- anti-inflammatory medications
- oral antibiotics
- nighttime ointment or moisture goggles
- therapeutic contact lenses
- intense pulsed light therapy
- amniotic membrane grafting
There are various home remedies and tips for managing dry eyes. Some options include:
- using an indoor humidifier to add moisture to the air and help prevent the eyes from drying out
- using an air filter to remove potential eye irritants from the air
- applying warm compresses to the eyes
- staying hydrated
- eating a sufficient amount of omega-3 fatty acids, which may help to reduce inflammation associated with dry eyes
There are many potential causes of dry eye besides thyroid issues. A
Lifestyle and environmental factors
The following lifestyle and environmental factors may cause or exacerbate dry eye:
- excessive computer or screen usage that causes reduced blinking
- exposure to certain environmental factors, such as:
- chemical fumes
- cigarette smoke
- low humidity
Certain underlying medical conditions may also result in dry eye. Examples include:
- excessive or inadequate amounts of vitamins, especially vitamin A
- ocular allergies
- skin conditions, such as eczema and rosacea
- autoimmune or connective tissue conditions, such as rheumatoid arthritis and lupus
- graft-versus-host disease, which is a complication of any organ transplant surgery that involves an abnormal immune response to cells or tissues from a donor
Medications and medical procedures
The following medical treatments may also increase the risk of dry eye:
- Certain medications, including:
- systemic hormones
- antihypertensives, which are medications for managing high blood pressure
- anticholinergic medications, which block the action of the neurotransmitter “acetylcholine”
- eye surgery, including:
- cataract surgery
- corneal transplant
- refractive surgery
- eyelid surgery
Thyroid eye disease commonly lasts between 6 months and 2 years. A person should seek treatment for dry eyes and other TED symptoms as soon as possible to reduce the risk of complications.
Complications from persistent dry eyes can be mild or severe. Some individuals experience constant redness and irritation. However, some more extreme symptoms include:
- infectious keratitis, which is infection-induced inflammation of the cornea
- eye ulceration
- scarring, which may lead to vision loss
Dry eyes can also impact an individual’s overall sense of well-being.
Anyone who experiences dry-eye symptoms should make an appointment with their doctor, regardless of whether they have a thyroid issue. A doctor will work to determine the cause of the dry eye and develop an appropriate treatment plan.
There are two main types of thyroid hormone imbalances: hyperthyroidism, in which the thyroid gland produces too much of its hormones, and hypothyroidism, in which the thyroid gland does not produce enough of them. Both types can affect the eyes. Doctors refer to thyroid-related eye diseases as “thyroid eye disease” (TED).
Thyroid eye disease may include dry eye, which a person can experience as eye pain, blurred vision, or photophobia. Treatment will typically incorporate environmental changes, such as eliminating exposure to direct airflow, using humidifiers in the home, and wearing sunglasses outdoors.
Doctors may also recommend medical treatments, such as eye drops, eye ointments, or therapeutic contact lenses.
A person should seek medical attention for dry eye as soon as symptoms develop. Doing so will help to reduce the risk of serious complications, such as permanent eye damage and vision loss.