Is Glaucoma Hereditary?

Around three million people in the United States have glaucoma. While anyone can develop the disease, patients with a family history of glaucoma are at a higher risk.

Yes, glaucoma is hereditary, but this does not necessarily mean patients are cursed by their genetics. Glaucoma is a complex condition with multiple factors that influence the course of the disease. Learning more about these factors can help patients understand and manage their condition.

Glaucoma is a progressive disease that damages the optic nerve. It occurs when fluid builds up and causes high pressure in the eye.

Our eyes produce a fluid called aqueous humor. Healthy eyes both drain and replenish this fluid to keep levels in balance. When the fluid cannot drain naturally and begins to accumulate, intraocular pressure builds up.

This pressure damages the eye’s optic nerves. When left untreated, the damage to the optic nerve can lead to vision loss and permanent blindness.

There are two primary types of glaucoma:

Open-angle glaucoma: This is the most common type of glaucoma, making up around 90% of cases. It occurs when the eye does not drain fluid as it should. Open-angle glaucoma is gradual. Patients may appear asymptomatic, but as pressure builds their vision will deteriorate.

Angle-closure glaucoma: This type of glaucoma is less common but more serious. It occurs when the iris blocks the eye’s drainage angle, causing pressure to rapidly rise. The rising pressure often leads to “acute attacks.” These sudden attacks can cause vision loss and are considered eye emergencies in which patients should seek immediate medical attention.

Glaucoma can be difficult to diagnose as symptoms build up slowly over time. In open-angle glaucoma, loss of peripheral vision is usually the first symptom to develop. Many people with open-angle glaucoma do not notice changes in vision until the damage becomes severe—which makes it vital that patients receive regular eye exams.

Patients are more likely to notice symptoms in closed-angle glaucoma as symptoms often manifest in an acute attack, which can include:

• Sudden blurry vision

• Severe eye pain

• Strong headache that can produce nausea and vomiting

• Seeing rainbow-colored rings or halos around light

Eye doctors can check for glaucoma during a comprehensive eye exam. During the exam, the doctor will typically apply drops to dilate a patient's eye. These drops widen the pupil, making it easier for the doctor to look at the optic nerve in the back of the eye.

During the exam the doctor may also:

• Measure a patient’s eye pressure

• Inspect the eyes’ drainage angle

• Test peripheral vision

• Take photos or computer measurements of the optic nerve

• Measure the thickness of the cornea

Unlike eye conditions such as cataracts, glaucoma is hereditary. Both types of glaucoma are affected by family history. A major study found that around half of people who develop open-angle glaucoma have a family history of the disease.

The closeness of the relatives affects the likelihood of developing the disorder. For instance, having a first-degree relative (parents, sibling, or children) with glaucoma produced a nine-fold increased risk of developing the disease.

These numbers may be even higher for people with angle-closure glaucoma. A recent study found that the risk of developing angle-closure glaucoma was as much as 13 times higher for people that had a sibling with the condition.

Glaucoma is a hereditary disease passed down through mutations in specific genes responsible for the eye’s outflow and drainage systems. There are a variety of mutations which have been tied to genes like MYOC and CYP1B1.

However, recent studies have linked glaucoma inheritance to as many as 17 different genes. There is still more research to be done in this area to understand how these genes interact and contribute to the disease.

Outside of genetics and family history there are a variety of risk factors for glaucoma. These include:

Age: The risk of glaucoma increases dramatically with age. Patients over 60 have the greatest risk of developing the disease.

Eye conditions and injuries: Severe injury or trauma to the eye puts patients at a greater risk for glaucoma. Tumors and inflammatory eye diseases may also increase risk.

Medical history: Conditions not directly related to the eyes such as diabetes, high blood pressure, and heart disease can increase the risk of developing glaucoma.

Corticosteroids: This class of anti-inflammatory medications are used to treat a variety of medical conditions such as rheumatoid arthritis, inflammatory bowel disease (IBD), and asthma. Use of these medications for prolonged periods of time can put some people at a greater risk of getting glaucoma.

Unfortunately there is no way to prevent glaucoma. What’s worse, many people remain unaware that they have the disease. Patients—with open-angle glaucoma in particular—may appear asymptomatic and not notice the condition until they experience vision loss.

This makes receiving regular eye exams crucial for managing glaucoma and preventing serious symptoms such as vision loss. This is particularly important for those with a family history of glaucoma.

If a patient knows glaucoma runs in their family, they should inform their eye doctor and make a point of scheduling regular check ups.

While patients cannot prevent glaucoma, there are things they can do to manage the condition and prevent the onset of more serious symptoms. In addition to regular eye exams, patients can make lifestyle changes such as:

• Maintaining a healthy, balanced diet that includes leafy greens, colored fruit, and other vision boosting foods.
  

• Engaging in moderate exercise such as brisk walking that can lower eye pressure and improve overall health.
  

• Protecting their eyes from injury and UV damage

In addition to basic eye care and lifestyle changes, there are a number of treatments available to those affected by the condition. These include:

Eyedrops: Prescription eye drops can reduce high pressure by either decreasing the aqueous humor created in the eye or by helping the fluid drain from the eye.

Laser Treatment: This glaucoma treatment, called selective laser trabeculoplasty (SLT), applies laser energy to drain fluid from the eye and lower pressure. At our office, we often recommend SLT as a first-line therapy.

Surgery: If a patient cannot manage glaucoma through eye drops or laser treatment, they can receive glaucoma surgery. Modern, minimally invasive glaucoma surgeries (MIGS) are considered the safest surgical option. MIGS avoid complications that may occur in more invasive glaucoma procedures.