Glaucoma is a group of eye diseases that can cause vision loss and blindness by damaging a nerve in the back of your eye called the optic nerve.
The symptoms can start so slowly that you may not notice them. The only way to find out if you have glaucoma is to get a comprehensive dilated eye exam.
Damage from glaucoma cannot be repaired. Vision loss from glaucoma is permanent.
There’s no cure for glaucoma, but early treatment can often prevent further damage and protect your vision.
Each type of glaucoma is different — but most have no early symptoms, so it’s important to get tested regularly, especially if you are at higher risk.
Types of Glaucoma
When experts don’t know what causes a type of glaucoma, that type is called a primary glaucoma.
Open-angle glaucoma is the most common type in the United States. It accounts for at least 90% of all glaucoma cases and affects about three million Americans.
It is called “Open-angle” because the angle where the iris meets the cornea is wide open and appears normal. However, the drainage canals in this angle slowly stop working properly and the eye pressure increases.
With this type of glaucoma, damage usually develops slowly, but the damage may go unnoticed until much of the vision is lost. Open-angle glaucoma causes almost 2 out of every 10 cases of blindness in African Americans.
Angle-closure glaucoma is less common than open-angle glaucoma. It is called “Angle-closure” because the angle where the iris meets the cornea is narrow and can close completely. This is called an “Angle-closure Attack.” This develops very quickly and causes a sudden increase in the eye pressure. This is an emergency requiring immediate medical attention to preserve vision.
Most types of glaucoma have elevated eye pressures. In normal-tension glaucoma, the optic nerve is damaged even though the eye pressure is not very high. This condition is poorly understood. Why some people’s optic nerves develop damage with normal pressure levels is unknown.
Some babies are born with glaucoma — this is called congenital glaucoma. About 1 out of 10,000 babies born in the United States have a defect (problem) in the eye that keeps fluid from draining normally. Surgery works very well to treat congenital glaucoma. If a doctor does surgery early enough, children with congenital glaucoma usually won’t have any permanent vision loss
Sometimes glaucoma is caused by another medical condition — this is called secondary glaucoma.
This type of glaucoma is caused by the accumulation of an abnormal protein in the drainage canals of the eye. This is a type of open-angle glaucoma with unique characteristics and physical findings.
It is more common in certain racial groups including people from:
- the Nordic countries
- the Mediterranean countries
Pseudoexfoliation glaucoma tends to cause higher eye pressures and faster damage than primary open-angle glaucoma.
A gene abnormality (LOXL1) has recently been associated with this type of glaucoma. However, there is little value in genetic testing for most patients, since Pseudoexfoliation material can easily be seen during a dilated eye examination.
Neovascular glaucoma happens when the eye makes extra blood vessels that cover the part of your eye where fluid would normally drain. It’s usually caused by another medical conditions that cause decreased blood flow to the eye, most commonly diabetes.
This type of glaucoma can be hard to treat. Doctors need to treat the underlying cause and use glaucoma treatments to lower the eye pressure that results from it.
Pigment dispersion syndrome happens when the pigment (color) from your iris (the colored part of your eye) flakes off. The loose pigment may block fluid from draining out of your eye, which can increase your eye pressure and cause pigmentary glaucoma. Doctors can treat pigmentary glaucoma by lowering eye pressure, but there currently isn’t a way to prevent pigment from detaching from the iris.
Uveitic glaucoma can happen in people who have uveitis, a condition that causes inflammation (irritation and swelling) in the eye. About 2 in 10 people with uveitis will develop uveitic glaucoma.
Experts aren’t sure how uveitis causes uveitic glaucoma, but they think that it may happen because uveitis can cause inflammation and scar tissue in the middle of the eye. This may damage or block the part of the eye where fluid drains out, causing high eye pressure and leading to uveitic glaucoma.
About 8% of people can have their eye pressure increase with the use of steroids. Steroid pills, inhalers, joint injections, and even over-the-counter creams, lotions and nasal sprays can cause this response. Although the pressure usually returns to normal a few weeks after stopping the steroid use, it can become a chronic problem.
Symptoms of Glaucoma
Half of all people with glaucoma don’t know they have it.
- Most types of glaucoma, have no early symptoms
- Vision loss is slow, usually starting with the peripheral vision, especially the part near your nose.
- This is very hard to detect without special testing
- A large portion of the vision must be lost before it is noticeable.
- Untreated glaucoma can lead to complete blindness.
Some types of glaucoma can cause rapid increases in the eye pressure and cause:
- Pain in your eye
- Red eyes
- Blurred vision
- Vision loss
If you have these symptoms, go to your doctor or an emergency room now. You can go blind without immediate treatment.
Risk Factors for Glaucoma
Anyone can get glaucoma, but some people are at higher risk.
- Age – Everyone over 60 years of age is at increased risk for open-angle glaucoma.
- Family History – The lifetime risk of developing glaucoma is as high as 22% in relatives of patients with glaucoma.
- Ethnicity – Certain ethnic groups have a higher risk of developing glaucoma
- Open-Angle Glaucoma
- African Americans over age 40
- Hispanics over age 60
- Angle-Closure Glaucoma
- Normal-Tension Glaucoma
- Pseudoexfoliation Glaucoma
- Mediterranean Origin
- Open-Angle Glaucoma
- Genetics – Mutations in the MYOC, OPTN and LOXL1 genes have been known to be associated with glaucoma for some time., but recently many more associated genes have been uncovered. This genetic information may increase our understanding of the causes and potential treatments of glaucoma. However, there is little benefit at this time in genetic testing for most patients.
- Findings on Examination – Certain characteristics of the eye may predispose to glaucoma
- High intraocular pressures
- Thin central corneas
- Thinning of the optic nerve rim
- Medical Conditions – Certain medical conditions may predispose to glaucoma
- High blood pressure
- Poor blood circulation
- Long-term Steroid Use – Use of steroid orally, topically or by injection anywhere in the body can increase the eye pressure.
- Trauma – Injuries to the eye can damage the drainage area of the eye and increase the eye pressure.
- Talk with your doctor about your risk for glaucoma, and ask how often you need to get checked.
There is no way to prevent glaucoma.
That’s why eye exams are so important — so you and your doctor can find it before it affects your vision.
Eye doctors can check for glaucoma as part of a comprehensive dilated eye exam. The exam is simple and painless — your doctor will give you some eye drops to dilate (widen) your pupil and then check your eyes for glaucoma and other eye problems. The comprehensive
Dilated Eye Examination – Dilating the pupil allows a better examination of the optic nerve head.
Tonometry – This measures the pressure inside the eye.
Gonioscopy – A special lens is used to examine the fluid outflow area where the iris meets the cornea.
Pachymetry – This is a measure of the central corneal thickness which has an effect on the intraocular pressure measurement and is an independent risk factor for glaucoma.
Perimetry – This measures the extent of the visual field. As glaucoma damages the optic nerve, the visual field gets smaller.
Optical Coherence Tomography – This machine is used to measure the thickness of the layer of cells in the retina that die in glaucoma.
Electrophysiology – Occasionally, the results of the other testing can be equivocal. In this situation, testing Visual Evoked Potentials or Pattern Electroretinography can be helpful.
iCare Home Tonometry – Home tonometry can be helpful in detecting elevations and fluctuations in the eye pressure that are not caught in the office.
If you have glaucoma, it’s important to start treatment right away. While it won’t undo any damage to your vision, treatment can stop it from getting worse.
The most common treatment for glaucoma is prescription eye drops. They work by lowering the pressure in your eye and preventing damage to your optic nerve. These eye drops won’t cure glaucoma or reverse vision loss, but they can keep glaucoma from getting worse. Some people with glaucoma stop using their eye drops after a while. They may forget, get out of the habit, or think the medicine isn’t helping. But remember, glaucoma eye drops won’t make you feel different or improve your vision. They prevent your vision from getting worse. If you don’t use them as prescribed, you could lose your vision.
Some types of eye drops work by helping fluid drain from your eye, which lowers eye pressure.
Prostaglandins – latanoprost (Xalatan), travoprost (Travatan Z), tafluprost (Zioptan), and bimatoprost (Lumigan)
Rho Kinase Inhibitors – netarsudil (Rhopressa)
Nitric Oxides – latanoprostene bunod (Vyzulta)
Miotic or Cholinergic Agents – pilocarpine (Isopto Carpine)
Other types of eye drops work by lowering the amount of fluid your eye makes.
Alpha-adrenergic Agonists – brimonidine (Alphagan P)
Beta Blockers – timolol (Betimol, Istalol, Timoptic) and betaxolol (Betoptic)
Carbonic Anhydrase Inhibitors – dorzolamide (Trusopt) and brinzolamide (Azopt)
To lower pressure in your eye, doctors can use lasers to help the fluid drain out of your eye. It’s a simple procedure that your doctor can do in the office.
Selective Laser Trabeculoplasty – This is a quick, painless procedure performed in the office. The outflow area of the eye is treated with a low-energy laser. This can lower the intraocular pressure over the following few weeks. The effect can last up to five years. Since it causes no damage to the eye, it can be repeated if the effect wears off.
Laser peripheral Iridotomy – This laser procedure is also performed in the office. A small hole about the size of a pinhead is made in the peripheral iris. It is used to prevent angle-closure in people at risk or to treat an acute angle- closure attack.
Endoscopic Cyclophotocoagulation – This procedure is performed in an operating room, frequently at the time of cataract surgery. A laser endoscope is placed into the eye and the area that produces fluid (the ciliary body) is treated. The treatment lowers pressure by reducing the amount of fluid produced.
If medicines and laser treatment don’t work, your doctor might suggest surgery. There are several different types of surgery that can help the fluid drain out of your eye.