Most people think of having their eyes checked when they experience blurry vision or want to purchase new eyeglasses or contact lenses.
You may not be aware of the many systemic diseases of the body that can be diagnosed from an eye exam. A dilated eye exam allows your eye doctor to look in the back of the eye at the blood vessels and retina to uncover signs of systemic diseases. Even if you are still seeing well, it is still important to have your eyes checked annually to make sure they are healthy.
Here are 10 systemic diseases that can be diagnosed by your doctor by looking at your eyes:
Diabetes is the leading cause of blindness in working-age adults. In diabetes, high glucose (sugar) levels break down the small blood vessels in the retina. Diabetic retinopathy is a result of an elevated Hemoglobin alc (HbA1c) level or having diabetes for a long period of time.
Type 1 diabetes is an autoimmune disease where your pancreas is unable to produce enough insulin. Those with type 1 diabetes are at a greater risk of developing eye problems than someone who is diagnosed later in life (Type 2). Type 2 diabetes is due to poor eating habits and lack of exercise.
Symptoms of diabetes in the eye include:
- Blurry vision
- Detachment of the retina (curtain in your vision)
It is advisable not to purchase new glasses or contact lenses if your sugar levels are uncontrolled. Diabetes can cause your prescription to change significantly.
By looking at the blood vessels in the back of your eye, your eye doctor can tell if you have chronic hypertension (high blood pressure). Hypertensive retinopathy is alterations in the small blood vessels in the eye and can even lead to swelling of the optic nerve if left untreated. Hypertension is usually due to poor diet or lack of exercise but may be genetic in certain cases.
Symptoms of hypertension in the eye include:
- Blurred vision
- Spotty vision
Hypercholesteremia presents in the eye as small, little yellow clots inside the blood vessels called Hollenhorst plaques.
Cholesterol plaques can block the tiny blood vessels in your eyes just like they can block blood vessels in the rest of the body leading to a heart attack or stroke. In the eye, they can cause “strokes of the eye” blocking the blood flow to the rest of the retina. These strokes can cause a partial or complete loss of vision. A symptom of hypercholesteremia in the eye is a temporary vision loss or dimming of the vision.
Multiple sclerosis (MS) is a demyelinating disease of the body’s central nervous system where communication is delayed between the brain and the body. MS is often diagnosed when the eye is affected by a condition called optic neuritis.
Optic Neuritis is inflammation of the optic nerve which delays or prevents messages sent back and forth to the brain. Common symptoms include pain in eye movements and a sudden loss of vision. Fortunately, with proper treatment, vision can be restored over a period of weeks to months.
Skin and systemic cancers
Additionally, many other cancers like melanoma can be found in the eye. Eye doctors also look at the skin around your eyes and your eyelids for cancers such as basal or squamous cell carcinoma. Any freckle that changes color, elevation, has new blood vessel growth, or seems to grow at an unusual rate should be looked at by a physician.
Sarcoidosis is inflammation in the body that results in the growth of tiny collections of inflammatory cells in the lungs, lymph nodes, eyes, and skin. Sarcoid is most often diagnosed from a cough; however, it can also present in the eye.
20% of sarcoid patients have symptoms that affect the eyes. Blurry, red, painful, and light-sensitive eyes are signs of uveitis or inner eye inflammation. Sarcoidosis can cause inflammation of the lacrimal gland, and inflammation in the back of the eye that looks like floaters. Sarcoidosis will not resolve without topical steroids for the eye and oral steroids for systemic inflammation.
The eye and the brain are very closely connected. For this reason, changes in your eyesight can cause headaches. Your eyes are connected to your brain by way of optic pathways and the complete pathway must function correctly for vision. 20% of stroke sufferers end up with a visual field defect of their peripheral vision. A stroke in the left side of your brain will affect your vision on the right side of both of your eyes because of the way the pathways crisscross from your eyes to your brain.
Visual symptoms of a stroke include:
- Loss of vision in one eye upon waking
- Double vision
- Difficulty navigating the world
- Bumping into people or objects
- Visual neglect
Benign tumors can affect the eye, brain, and/or the pathways connecting them. One common tumor is called a pituitary adenoma (pituitary tumor) and is estimated to occur in up to 20% of all people.
While these tumors are benign and slow-growing, they can affect your vision. The exact cause is unknown but thought to be genetic. The pituitary gland is located near the optic chiasm of the eye, and as the tumor grows it can compress on the pathway resulting in blurry vision, double vision, vision loss, headaches as well as many systemic symptoms.
Rheumatoid arthritis/autoimmune conditions
Many autoimmune conditions are diagnosed first by presentation in the eye as uveitis. Uveitis is active inflammation in the front of the eye called the anterior chamber. It can also progress to the middle and back of the eye.
If you have uveitis multiple times, it is often an indication of inflammation within the body. Your doctor may send you for bloodwork to rule out the various autoimmune conditions that may cause uveitis. A red, light-sensitive, painful eye with or without blurry vision may be uveitis. Uveitis needs to be seen and treated by a doctor treated to avoid vision loss. Other autoimmune conditions that may present as uveitis arthritis include:
- Ankylosing spondylitis
- Ulcerative colitis
- Kawasaki disease
- Crohn’s disease
Often, autoimmune conditions must be treated systemically with oral steroids like Prednisone to control the inflammation in the eye.
Hyperthyroidism (Graves’ Disease) is an autoimmune condition where immune cells attack the thyroid gland resulting in the secretion of an excess amount of thyroid hormone, and an enlarged thyroid gland. Additionally, the immune system attacks the tissue around the eye causing the eye muscles to expand.
The eyes are very vulnerable to Grave’s eye disease. Ocular symptoms and signs can vary from mild to severe and include bulging of the eye, double vision, and discomfort around the eyes on eye movements. 10-20% of patients have the sight-threatening disease.
Other symptoms of Graves’s eye disease include:
- Red eyes
- Swelling around the eyes
- Dry eyes if the eyelids cannot close completely over bulging eyes
- Increased pressure inside the eye orbit
The symptoms of Grave’s disease must be treated systemically and ocularly. Ocular treatments center around treating red, dry eyes.
As you can see, having your eyes checked is about much more than just getting new glasses or contacts. Having your eyes checked annually is important for preserving your vision and it could save your life!