Glaucoma Questions & Answers
Glaucoma is a leading cause of preventable vision loss and blindness in adults in the United States and Canada and the second leading cause of blindness in the World.
What is Glaucoma?
Glaucoma is generally described as a painless eye disease that is characterized by high fluid pressure in your eye (inter-ocular pressure) that damages the optic nerve and surrounding tissue in the eye.
When detected in the early stages, glaucoma can often be controlled, preventing severe vision loss and blindness. However, symptoms of noticeable vision loss often only occur once the disease has progressed. This is why glaucoma is called “the sneak thief of sight”. Unfortunately, once vision is lost from the disease, it usually can’t be restored.
What are the causes of glaucoma?
We don’t really know what causes glaucoma, but, we know there are certain risk factors. At Garden Grove Optometry, we screen everyone for this sight-threatening disease and closely monitor anyone who is more of a “suspect”.
Who is at risk for it?
Everyone is at risk of developing glaucoma, but, we know that certain risk factors such as your age, a family history of glaucoma, an African-American, Asian or Latino heritage, and/or cardiovascular diseases (like diabetes) will put you in a higher risk category.
Prevention is possible only with early detection and treatment. Since symptoms are often absent, regular eye exams which include a glaucoma screening are essential, particularly for individuals at risk of the disease. While anyone can get glaucoma, the following traits put you at a higher risk:
- Age over 60
- Hispanic or Latino descent, Asian descent
- African Americans over the age of 40 (glaucoma is the leading cause of blindness in African Americans, 6-8 times more common than in Caucasians.)
- Family history of glaucoma
- People with severe nearsightedness
- Certain medications (e.g. steroids)
- Significant eye injury (even if it occurred in childhood)
How is glaucoma harmful to vision?
Most forms of glaucoma are a slow, painless degenerative decrease in your peripheral vision, and then eventually, it will affect your central vision.
Can glaucoma cause blindness?
With the advances in our technology and treatments, most patients who see their optometrists regularly never lose their eyesight completely.
What are the signs of glaucoma?
The most common type of glaucoma, Open Angle Glaucoma, typically doesn’t have any warning signs. There is a more rare, aggressive, sudden type of glaucoma, called Angle Closure Glaucoma, where you will have pain, blurred vision, and a red eye. At Garden Grove Optometry, our eye doctors will look to see if you are at risk for this often blinding form of glaucoma as well.
The primary forms of glaucoma are open-angle and narrow-angle, with open-angle being the most common type.
Primary open-angle glaucoma (POAG) gradually progresses without pain or noticeable vision loss initially affecting peripheral vision. By the time visual symptoms appear, irreparable damage has usually occurred, however the sooner treatment starts the more further vision loss can be prevented. When untreated, vision loss will eventually result in total loss of side vision (or tunnel vision) and eventually total vision loss.
Normal-tension glaucoma or low-tension glaucoma is another form of open-angle glaucoma in which the intraocular pressure remains within the normal level. The cause of this form of glaucoma is not known, but it is believed to have something to do with insufficient blood flow to the optic nerve, causing damage. Individuals of Japanese descent, women and those with a history of vascular disease or low blood pressure are at higher risk.
Angle-closure glaucoma can be a sudden increase in eye pressure causing severe pain, blurred vision, halos, nausea and headaches. The pressure is caused by a blockage in fluid at the front of the eye which is a medical emergency and should be treated immediately. Without prompt treatment to clear the blockage vision can be permanently lost.
Congenital glaucoma is an inherited form of the disease that is present at birth. The babies are born with a defect that slows the normal drainage of fluid out of the eye and are usually diagnosed by the time they turn one. In these cases there are typically some noticeable symptoms such as excessive tearing, cloudiness or haziness of the eyes, large or protruding eyes or light sensitivity. Surgery is usually performed with a very high success rate of restoring full vision.
Secondary glaucomas are complications that develop from eye surgeries, injuries or other medical conditions such as cataracts, tumors, or a condition called uveitis which causes inflammation. Uncontrolled high blood pressure or diabetes can result of another serious form called neovascular glaucoma.
Pigmentary glaucoma is a rare form in which pigment from the iris sheds and clogs the drainage of fluid from the eye resulting in inflammation and damage to the eye and drainage system. .
Treatment of glaucoma is dependant upon the severity and type of glaucoma present.
How is glaucoma detected?
The best way to detect glaucoma is by having regular eye exams with our optometrists to establish a “baseline” on what is normal for your eyes. Then, we can compare this data year to year and look for small changes that would alert your optometrist that there may be a problem. What is “normal” for one person, may not be normal for another person.
During a routine comprehensive eye exam to check for glaucoma, your eye doctor will dilate your eye to examine the optic nerve for signs of glaucoma and will also measure the intraocular pressure (IOP) with an instrument called a tonometer. Tonometry involves numbing the eye with drops and then gently pressing on the surface of the eye to measure the pressure. Since your IOP can fluctuate throughout the day and glaucoma can exist without elevated IOP this is not enough to rule out the disease. If there are signs of the disease, further testing will be performed.
What is the Visual Field Test?
A visual field test is designed to detect any blind spots in your peripheral or side field of vision. You will be asked to place your head in front of a machine while looking ahead and indicate when you see a signal in your peripheral field of view.
Your doctor may also measure the thickness of the cornea with an ultrasonic wave instrument in a test called pachymetry or use imaging techniques such as digital retina scanning or optical coherence tomography (OCT) to create an image of your optic nerve to look for glaucoma damage.
How is glaucoma treated?
Most glaucoma is managed with eye drops. Sometimes we will also recommend laser treatments as well.
Can glaucoma be prevented?
The best way to prevent glaucoma is by yearly eye exams and living a healthy lifestyle.
Learn about Management of Ocular Diseases at Garden Grove Optometry