Glaucoma: Types, Symptoms, Diagnosis, and Treatment
Author: Disabled World (DW)
Updated/Revised Date: 30 Jul 2026
Table of Contents:
Synopsis - Definition - About This Section - FAQs - Publications - Subtopics
Synopsis
Learn about glaucoma, an optic nerve disease that can cause blindness, including its types, symptoms, eye exam diagnosis, risk factors, and treatments.
At a Glance
- 1 - The optic nerve carries vision from the retina to the brain through more than one million nerve endings.
- 2 - Open-angle glaucoma makes up about 90 percent of U.S. cases and is painless, with only gradual peripheral vision loss as a sign.
- 3 - Angle-closure glaucoma is a medical emergency that can cause blindness within one or two days without prompt laser surgery and medication.
- 4 - A comprehensive diagnosis uses tests including tonometry for eye pressure, pachymetry for corneal thickness, and visual field testing for side vision loss.
Topic Definition
- Glaucoma
Glaucoma is a group of eye disorders that damage the optic nerve, the bundle of over a million nerve fibers that carries visual information from the retina to the brain, and it is frequently linked to raised fluid pressure inside the eye. The condition falls broadly into two categories, open-angle and closed-angle (or angle-closure) glaucoma, and it can slowly steal sight or, in severe cases, lead to irreversible blindness. Because the most common form is painless and produces no early warning signs, many people do not realize they have it until vision is already lost, which is why regular dilated eye exams matter so much. Glaucoma often runs in families and may not appear until later in life, but with early diagnosis it can usually be managed with medication, laser treatment, or conventional surgery to protect remaining vision.
Overview
Glaucoma is a term describing a group of ocular disorders that result in optic nerve damage, often associated with increased fluid pressure in the eye. The disorders can be roughly divided into two main categories, "open-angle" and "closed-angle" (or "angle closure") glaucoma. Glaucoma can result in vision loss and in extreme cases, blindness. Glaucoma tends to be inherited and may not show up until later in life. However, with early diagnosis, you can often treat your eyes and guard them from serious vision loss.
The optic nerve is a bundle of more than 1 million nerve endings. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
Open-angle glaucoma is the most common form. Open-angle glaucoma accounts for 90% of glaucoma cases in the United States. It is painless and does not have acute attacks. The only signs are gradually progressive visual field loss, and optic nerve changes (increased cup-to-disc ratio on fundoscopic examination).
Closed-angle glaucoma accounts for less than 10% of glaucoma cases in the United States, but as many as half of glaucoma cases in other nations (particularly Asian countries). About 10% of patients with closed angles present with acute angle closure crises characterized by sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure (>30 mmHg), nausea and vomiting, suddenly decreased vision, and a fixed, mid-dilated pupil. It is also associated with an oval pupil in some cases. Acute angle closure is an emergency.
Types of Glaucoma
Low-tension or Normal-tension Glaucoma
Optic nerve damage and narrowed side vision occur in people with normal eye pressure.
Lowering eye pressure at least 30 percent through medicines slows the disease in some people. Glaucoma may worsen in others despite low pressures.
A comprehensive medical history is important in identifying other potential risk factors, such as low blood pressure, that contribute to low-tension glaucoma. If no risk factors are identified, the treatment options for low-tension glaucoma are the same as for open-angle glaucoma.
Angle-closure Glaucoma
The fluid at the front of the eye cannot reach the angle and leave the eye. The angle gets blocked by part of the iris.
People with this type of glaucoma have a sudden increase in eye pressure.
Symptoms include severe pain and nausea, as well as redness of the eye and blurred vision. If you have these symptoms, you need to seek treatment immediately.
This is a medical emergency. If your doctor is unavailable, go to the nearest hospital or clinic. Without treatment to improve the flow of fluid, the eye can become blind in as few as one or two days. Usually, prompt laser surgery and medicines can clear the blockage and protect sight.
Congenital Glaucoma
Children are born with a defect in the angle of the eye that slows the normal drainage of fluid. These children usually have obvious symptoms, such as cloudy eyes, sensitivity to light, and excessive tearing.
Conventional surgery typically is the suggested treatment, because medicines may have unknown effects in infants and be difficult to administer.
Surgery is safe and effective. If surgery is done promptly, these children usually have an excellent chance of having good vision.
Secondary Glaucomas
These can develop as complications of other medical conditions.
These types of glaucomas are sometimes associated with eye surgery or advanced cataracts, eye injuries, certain eye tumors, or uveitis (eye inflammation).
Pigmentary glaucoma occurs when pigment from the iris flakes off and blocks the mesh-work, slowing fluid drainage.
Glaucoma Eye Exam
Glaucoma is detected through a comprehensive dilated eye exam that includes the following:
- Visual acuity test: This eye chart test measures how well you see at various distances.
- Visual field test: This test measures your peripheral (side vision). It helps your eye care professional tell if you have lost peripheral vision, a sign of glaucoma.
- Dilated eye exam: In this exam, drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
- Pachymetry: The measurement of the thickness of your cornea. Your eye care professional applies a numbing drop to your eye and uses an ultrasonic wave instrument to measure the thickness of your cornea.
- Tonometry: The measurement of pressure inside the eye by using an instrument called a tonometer. Numbing drops may be applied to your eye for this test. A tonometer measures pressure inside the eye to detect glaucoma.
A severe form, called neovascular glaucoma, is linked to diabetes.
Glaucoma Facts and Statistics
- After cataracts, glaucoma is the leading cause of blindness among African Americans.
- Estimates put the total number of suspected cases of glaucoma at over 60 million worldwide.
- Blindness from glaucoma is 6 to 8 times more common in African Americans than Caucasians.
- African Americans are 15 times more likely to be visually impaired from glaucoma than Caucasians.
- It is estimated that over 2.2 million Americans have glaucoma but only half of those know they have it.
- In the U.S., more than 120,000 are blind from glaucoma, accounting for 9% to 12% of all cases of blindness.
- Glaucoma is the second leading cause of blindness in the world, according to the World Health Organization.
- The most common form, open-angle glaucoma, accounts for 19% of all blindness among African Americans compared to 6% in Caucasians.
- Other high-risk groups include: people over 60, family members of those already diagnosed, diabetics, and people who are severely nearsighted.
- Glaucoma causes irreversible blindness and many (50%) of the affected people are unaware of their condition.
- Glaucoma is second only to cataract as the leading cause of preventable blindness in the world. It is estimated that over 65 million people throughout the world are affected by glaucoma.
- Corticosteroid drugs used to treat eye inflammations and other diseases can trigger glaucoma in some people. Treatments include, but are not limited to, medicines, laser surgery, or conventional surgery.
Frequently Asked Questions
Can glaucoma be cured?
There is no cure for glaucoma, and vision already lost cannot be restored, but treatment can lower eye pressure and slow or halt further damage when started early.
Is glaucoma painful?
The most common open-angle form is usually painless, while angle-closure glaucoma can cause sudden severe eye pain, nausea, and blurred vision that require emergency care.
At what age should I start getting screened for glaucoma?
Many eye specialists suggest a baseline eye exam in your 40s, with earlier and more frequent screening for people who have a family history, diabetes, or other risk factors.
Can lifestyle changes help manage glaucoma?
While medication and surgery are the main treatments, regular exercise, a healthy diet, and avoiding activities that spike eye pressure may support overall eye health alongside medical care.
Does glaucoma always lead to blindness?
No, most people who receive an early diagnosis and follow their treatment plan retain useful vision, though untreated glaucoma can progress to blindness.
How is glaucoma treated with medication?
Glaucoma is often managed with prescription eye drops that either reduce fluid production or improve drainage, and consistent daily use is important for keeping eye pressure controlled.
Can glaucoma affect both eyes at the same time?
Glaucoma can affect both eyes, though it often progresses at different rates in each eye, which can make early vision loss harder to notice without an exam.
Curated and edited by Ian C. Langtree, Founder & Editor-in-Chief, Disabled World. This section is maintained by the Disabled World editorial team.
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