Overview Of Glaucoma
Glaucoma is a group of eye conditions that can damage the optic nerve. This nerve sends the images you see to your brain.
Most often, optic nerve damage is caused by increased pressure in the eye. This is called intraocular pressure.
Commonly Associated With
Open-angle glaucoma; Chronic glaucoma; Chronic open-angle glaucoma; Primary open-angle glaucoma; Closed-angle glaucoma; Narrow-angle glaucoma; Angle-closure glaucoma; Acute glaucoma; Secondary glaucoma; Congenital glaucoma; Vision loss – glaucoma
Causes Of Glaucoma
This condition is the second most common cause of blindness in the United States. There are four major types of glaucoma:
- Angle-closure , also called closed-angle
The front part of the eye is filled with a clear fluid called aqueous humor. This fluid is made in an area behind the colored part of the eye (iris). It leaves the eye through channels where the iris and cornea meet. This area is called the anterior chamber angle, or the angle. The cornea is the clear covering on the front of the eye that covers the iris, pupil, and angle.
Anything that slows or blocks the flow of this fluid will cause pressure to build up in the eye.
In open-angle glaucoma, the increase in pressure is often small and slow.
In closed-angle glaucoma, the increase is often high and sudden.
Either type can damage the optic nerve.
Open-angle glaucoma is the most common type.
The cause is unknown. The increase in eye pressure happens slowly over time. You cannot feel it.
The increased pressure pushes on the optic nerve. Damage to the optic nerve causes blind spots in your vision.
Open-angle tends to run in families. Your risk is higher if you have a parent or grandparent with the condition. People of African descent are also at higher risk for this disease.
Closed-angle glaucoma occurs when the fluid is suddenly blocked and cannot flow out of the eye. This causes a quick, severe rise in eye pressure.
Dilating eye drops and certain medicines may trigger an acute attack.
Closed-angle glaucoma is an emergency.
If you have had acute glaucoma in one eye, you are at risk for it in the second eye. Your health care provider is likely to treat your second eye to prevent the first attack in that eye.
Secondary glaucoma occurs due to a known cause. Both open- and closed-angle can be secondary when caused by something known. Causes include:
- Medicines such as corticosteroids
- Eye diseases, such as uveitis (an inflammation of the middle layer of the eye)
- Diseases such as diabetes
- Eye injury
- Congenital glaucoma occurs in babies.
- It often runs in families.
- It is present at birth.
- It is caused when the eye does not develop normally.
Symptoms Of Glaucoma
- Most people have no symptoms.
- Once you are aware of vision loss, the damage is already severe.
- Slow loss of side (peripheral) vision (also called tunnel vision).
- Advanced stages of this disease can lead to blindness.
Symptoms may come and go at first, or steadily become worse. You may notice:
- Sudden, severe pain in one eye
- Decreased or cloudy vision, often called “steamy” vision
- Nausea and vomiting
- Rainbow-like halos around lights
- Red eye
- Eye feels swollen
Symptoms are most often noticed when the child is a few months old.
- Cloudiness of the front of the eye
- Enlargement of one eye or both eyes
- Red eye
- Sensitivity to light
- Symptoms are most often related to the underlying problem causing this condition.
- Depending on the cause, symptoms may either be like open-angle or angle-closure.
Exams & Tests
The only way to diagnose this condition is by having a complete eye exam.
You will be given a test to check your eye pressure. This is called tonometry.
In most cases, you will be given eye drops to widen (dilate) your pupil.
When your pupil is dilated, your eye doctor will look at the inside of your eye and the optic nerve.
Eye pressure is different at different times of the day. Eye pressure can even be normal in some people. So you will need other tests to confirm glaucoma. They may include:
- Using a special lens to look at the angle of the eye (gonioscopy).
- Photographs or laser scanning images of the inside of your eye (optic nerve imaging).
- Laser scanning images of the angle of the eye.
- Checking your retina — The retina is the light-sensitive tissue at the back of your eye.
- Checking how your pupil responds to light (pupillary reflex response).
- 3-D view of your eye (slit-lamp examination).
- Testing the clearness of your vision (visual acuity).
- Testing your field of vision (visual field measurement).
Treatment Of Glaucoma
The goal of treatment is to reduce your eye pressure. Treatment depends on the type of eye disease that you have.
- If you have open-angle, you will probably be given eye drops.
- You may need more than one type. Most people can be treated with eye drops.
- Most of the eye drops used today have fewer side effects than those used in the past.
- You also may be given pills to lower pressure in the eye.
- If drops alone do not work, you may need other treatment:
- Laser treatment uses a painless laser to open the channels where fluid flows out.
- If drops and laser treatment do not work, you may need surgery. The doctor will open a new channel so fluid can escape. This will help lower your pressure.
- Recently, new implants have been developed that can help treat this condition in people having cataract surgery.
ACUTE ANGLE GLAUCOMA
- An acute angle-closure attack is a medical emergency. You can become blind in a few days if you are not treated.
- You may be given drops, pills, and medicine given through a vein (by IV) to lower your eye pressure.
- Some people also need an emergency operation, called an iridotomy. The doctor uses a laser to open a new channel in the iris. Sometimes this is done with surgery. The new channel relieves the attack and will prevent another attack.
- To help prevent an attack on the other eye, the same procedure will often be performed on the other eye. This may be done even if it has never had an attack.
- Congenital glaucoma is almost always treated with surgery.
- This is done using general anesthesia. This means the child is asleep and feels no pain.
- If you have secondary glaucoma, treating the cause may help your symptoms go away. Other treatments also may be needed.