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What is Glaucoma?

Glaucoma, which can damage the optic nerve, frequently progresses without symptoms until permanent vision loss has occurred. That’s why it’s crucial to have frequent eye exams to look for signs of glaucoma and other eye diseases.

What is Glaucoma?

Glaucoma is a group of eye conditions usually caused by the buildup of pressure within the eye. Left untreated, glaucoma eventually leads to permanent damage to the optic nerve that connects the eye to the brain, causing vision loss.

Although glaucoma is a leading cause of blindness in people 60 and older, when diagnosed early and managed effectively, vision loss can be prevented or minimized.

Why is Glaucoma Called the ‘Silent Thief of Sight’?

Glaucoma is known as the ‘silent thief of sight’ because it is painless and causes significant vision loss before most people even recognize the first signs. It can silently ‘steal’ your vision and result in irreversible nerve damage that cannot be restored.

The most effective way to prevent glaucoma is to undergo a comprehensive eye exam even if you think your vision is clear, as the earlier this serious eye condition is diagnosed the better the outcome.

Types of Glaucoma

There are several kinds of glaucoma. The three most common types are open-angle glaucoma, narrow-angle glaucoma and normal tension glaucoma.

Open-Angle Glaucoma

Open-angle glaucoma, or primary open-angle glaucoma, is the most common type of glaucoma, affecting roughly 95% of patients with the disease. In open-angle glaucoma, the aqueous fluid within the eye can reach the drainage system, but the drainage system itself does not function well. The resulting fluid buildup causes eye pressure to rise to dangerous levels – above the range of 12-22mm Hg.

Most individuals with open-angle glaucoma don’t even know that they have high eye pressure, because this condition has no noticeable or obvious symptoms in its early stages. By the time symptoms appear, the optic nerve has been irreparably damaged. Regular comprehensive eye exams are the only way to prevent or minimize vision loss.

Narrow-Angle Glaucoma

Narrow-angle glaucoma, which represents only 2-3% of glaucoma cases, occurs when the eye’s drainage system is obstructed or blocked by the iris. When the aqueous fluid cannot drain out of the eye, eye pressure can increase quickly, causing extreme eye pain and blurred vision. If the eye pressure is too high for too long, permanent optic nerve damage can occur, resulting in loss of peripheral vision or total blindness.

Narrow-angle glaucoma is a medical emergency.

Normal Tension Glaucoma

Normal-tension glaucoma (NTG), also known as low tension or normal pressure glaucoma, is similar to open angle glaucoma. However, in this type of glaucoma, eye pressure does not exceed the normal pressure range, which is between 12 and 22 mm Hg.

Glaucoma Symptoms

The early stages of glaucoma are usually asymptomatic, meaning people will not know they have this serious eye condition until it’s too late.

Later symptoms of open-angle glaucoma include loss of peripheral (side) vision and blind spots in your vision. Untreated glaucoma may result in ‘tunnel vision,’ where only your central vision remains and is similar to looking through a narrow tube.

Narrow-angle glaucoma can cause severe eye pain, halos around lights, nausea, headaches and blurry vision.

Glaucoma causes damage to the optic nerve, which is the only connection between the brain and the eyes. Once the nerve is damaged, any vision loss is irreversible.

Glaucoma Treatment

There is no cure for glaucoma, but a thorough treatment plan can control the condition. Your eye doctor will discuss treatment options and develop a plan to minimize damage to the optic nerve.

Eye Drops and Medications for Glaucoma

There are several different types of eye drops and medications designed to manage glaucoma. These are often an initial treatment option but are only effective if used correctly and consistently. If your glaucoma does not respond to eye drops or medication, your eye doctor may recommend oral medication or a laser or surgical procedure.

Laser Glaucoma Treatments

When medications or eye drops are ineffective, your eye doctor may recommend laser surgery. Laser treatment can also be utilized as a first-line treatment option. Open-angle glaucoma is commonly treated with selective laser trabeculoplasty (SLT). This works by lowering pressure by improving the eye’s drainage mechanism. LPI (laser peripheral iridotomy) is a procedure for preventing or treating narrow-angle glaucoma by ablating a hole in the iris.

Minimally Invasive Glaucoma Surgery (MIGS)

MIGS (minimally invasive glaucoma surgery) is a cutting-edge treatment option for glaucoma that uses microscopic-sized devices to promote fluid outflow from the eye. MIGS comes in a variety of forms, some of which are designed to be used in conjunction with cataract surgery.


A trabeculectomy, commonly known as glaucoma filtration surgery, is a surgical treatment that provides a new drainage channel when the eye’s natural drainage system is blocked. Patients who have not responded to earlier therapies or who are not MIGS candidates may be candidates for this surgery.

Aqueous Shunt

Aqueous shunts are tiny devices that are placed in the anterior chamber of the eye to reduce excessive pressure. This treatment can be used to treat a variety of glaucoma conditions, and may be a viable alternative for patients who do not qualify for trabeculectomy. The aqueous shunt is a thin silicone tube with a small plate attached that effectively drains surplus fluid out of the eye.

At VisionMD Eye Doctors in Glenn Dale our eye doctors are highly experienced in diagnosing and treating glaucoma, and offer you personalized care and the most advanced treatment options.