Glaucoma- common form (POAG)

Table of Contents

Medicare part B benefit for High Risk Patients.

In 2011 Medicare began covering an annual glaucoma screening exam for High-Risk patients. You are considered at high risk for glaucoma if you have diabetes, have a family history of glaucoma, are African-American over the age of 50 or Hispanic-American over the age 65.

What is glaucoma?

Glaucoma is a condition in which the nerve cells and nerve fibers inside the eye are destroyed.

Is there more than one type of glaucoma?

There are several types. The most common is the Primary Open Angle Glaucoma or POAG. It is painless, chronic and takes a long time to damage the eye.

Another is the Narrow (Closed) Angle Glaucoma or NAG. It is less common than POAG but an attack of Narrow Angle Glaucoma is an emergency because it can damage the eye very quickly. These two conditions are very different. If you have glaucoma, make sure to ask the doctor which type you have.

What is Primary Open Angle Glaucoma (POAG)?

This is the most common type of glaucoma. When we talk about “glaucoma”, this is the type we are talking about. When we talk about the Narrow Angle Glaucoma (NAG) we will let you know about it.

What happens to the eye in POAG?

Each eye has about 1 million nerve cells and fibers. They come together in the back of the eye to make up the eye nerve. Glaucoma destroys nerve cells and fibers and when many are lost, the eye becomes blind.​

What are the symptoms of early POAG?

There are no symptoms until very late in the disease. There is no pain.

What are the symptoms of late POAG?

Side vision is lost. The field of vision narrows. The patient feels as if he is looking through a long narrow tube. Just the central, straight ahead vision is clear. When driving across an intersection such a patient might be able to read the license plate of the car in front of him, but would not be able to see the bus coming at him from the side.

At a health screening my eye pressure was high. Do I have glaucoma?

You have either glaucoma or ocular hypertension. If you have nerve loss, you have glaucoma.

How do you determine that there is nerve fiber loss?

By carefully examining the eye nerve and by doing certain tests OCT, FDT and Visual Fields tests. We also take eye fundus photographs to help us identify nerve changes from previous visits. Changes may indicate glaucoma progression and the need to adjust or change medication.

What is Ocular Hypertension?

Ocular Hypertension is a mild increase in eye pressure with no nerve damage. It requires no treatment. It must be followed up carefully to detect nerve fiber loss as early as possible.

My eye pressure is normal. Is it safe to say I do not have glaucoma?

No. Pressure screening detects about one-half to two-thirds of glaucoma cases. The rest are missed.

Does increased eye pressure mean glaucoma?

The popular concept that glaucoma is simply high pressure inside the eye is not correct.
Briefly, here are the common situations:

  • People with high eye pressure and nerve damage have Glaucoma.
  • People with high eye pressure and no nerve damage have Ocular Hypertension.
  • People with normal eye pressure and nerve damage have Normal Tension or Low Tension Glaucoma (a special form of glaucoma).

How can I be sure I do not have glaucoma?

You need a complete, dilated eye exam. We routinely check the nerve, the eye pressure, and the eye fluid draining area. If this eye exam is normal, and you do not have family history of glaucoma, it is pretty safe to assume that you do not have glaucoma.

If you have a blood relative with glaucoma you may need, in addition to the eye exam, a nerve fiber analysis test (OCT test).

How is glaucoma diagnosed (POAG)?

The key is to identify loss of nerve fibers. Loss of nerve fibers is suspected from the appearance of the nerve in the back of the eye. A positive Visual Fields test or a positive OCT test confirms it. Sometimes, when the pressure in the eye is very high, glaucoma is diagnosed even without proving nerve fiber loss.

If I have glaucoma - How often do my eyes need to be examined?

When the glaucoma is first diagnosed you will be seen at short intervals to evaluate results of treatment. The desirable level of control is different for each individual. Once good control is obtained you will usually need to be examined every 6 months, depending on severity of glaucoma.

I was told I am a Glaucoma Suspect. What now?

This means that your eye pressure is higher than normal or the nerve looks abnormal. It is important to find out if what you have is glaucoma (for which you will need lifetime treatment) or if it is some other condition which looks like glaucoma but it is not (and, therefore does not need to be treated). It is often difficult to exclude early glaucoma. You will need close follow up with careful dilated eye examinations, the Visual Fields test and the OCT test. Fundus photos (optic nerve photos) will also be taken to compare the nerve appearance and detect if any change (progression) is occurring over time.

My mother (sister, any blood relative) has glaucoma. How significant is this?

If one of your parents has glaucoma, your chance of developing glaucoma is increased 10 fold. If your brother or sister has glaucoma your risk is increased 20 fold (1 chance in 10 that you will develop glaucoma).

What are the chances my children will develop glaucoma?

If you have glaucoma, your children’s chance of developing glaucoma is 10 times greater than for other children (1chance in 25).

Should my family members be checked for glaucoma?

Yes. If you are diagnosed with glaucoma your blood relatives (parents, children, brothers, sisters) should have a complete eye exam. When they see us, they must tell the examining doctor that they are blood relatives of a patient with glaucoma.

What is the OCT test?

A laser-based computerized test that measures the thickness of the eye nerve tissue. It is similar to taking a picture of the inside of the eye. It is painless, quick and does not require that your eyes be dilated. It is used for diagnosis of early glaucoma; for follow up of glaucoma treatment and in early detection of glaucoma in relatives of glaucoma patients. It is also used in many retinal conditions.

What is the Visual Fields test?

It is a test of eye nerve function. Faint spots of light are projected on a screen and you press a button if you see them. The computer tells us if you are missing spots you should have been able to see.

Why do you do the OCT test and the Visual field tests?

They measure different aspects of the nerve. Both are necessary for best evaluation. The Visual Fields test measures functioning nerve fibers. About 300,000 nerve fibers (out of 1 million) have to be lost before the Visual Fields test becomes positive. The OCT test often detects nerve damage earlier than the Visual Fields tests. Another visual fields test we use is the Frequency Doubling Technology. The various tests provide complementary bits of information.

What is the Fundus Camera?

Fundus Camera obtains images of the nerve head. These images are then used as a baseline against which later images are compared. Minute changes indicative of progression of glaucoma are detected early and treatment can be adjusted sooner.

What medicines should open angle glaucoma (POAG) patients avoid?

Steroids (cortisone, hydrocortisone, prednisolone, etc.) increase eye pressure. If you need to use steroids for longer than 2 weeks, your eye pressure has to be monitored during use. This includes use of steroid-containing eyedrops, steroid pills, and steroid creams over large areas of the body. Use of steroid creams for small skin lesions is unlikely to increase eye pressure. If you are taking steroids now, do not discontinue them – just tell us about it and come in for a re-evaluation. Steroid use for less than 2 weeks generally does not require special monitoring of eye pressures.

What medicines are generally considered safe for open angle glaucoma (POAG) patients?

Cold remedies containing Pseudoephedrine, Phenylephrine or Neo-Synephrine; anti-histaminics Chlorpheniramine, Diphenhydramine or Benadryl and overactive bladder remedies such as Detrol often carry a warning telling you not to use them if you have glaucoma. These warnings do not apply if you have the  common form of glaucoma (POAG). You can safely use them for a week or two; beyond that, monitoring may be needed. The warnings are intended primarily for patients with Narrow Angle Glaucoma because in such patients these drugs may precipitate an acute glaucoma attack (often painful). If you are not sure what type of glaucoma you have, consult us before taking these medicines.

Why is it important to recognize glaucoma progression early?

Because nerve cells and fibers, once lost, cannot be replaced. Since treatment slows down the rate of loss, it should begin as soon as we detect progressive nerve loss.

How do we treat open angle glaucoma (POAG)?

Normally, we start treatment of chronic open angle glaucoma (POAG) with eye drops. They are generally well tolerated and control glaucoma in most patients. The downside is that eye drops can be very expensive, a serious consideration when the need for medication is a lifetime need.

Laser surgery is used whenever eye drops fail to control glaucoma. It is also an excellent option for those who tend to forget to use the eye drops, have problems administering them, cannot tolerate them for any reason, do not wish to use medications because of pregnancy or find the eye drops too expensive. Laser surgery is a well established procedure, covered by Medicare and other insurances, with little or no out-of-pocket expenses. We do laser surgery in the office.

SLT - Laser surgery for open-angle (POAG) type glaucoma.

Selective Laser Trabeculoplasty (SLT) is a painless, in-office treatment for glaucoma. You can drive yourself home after the procedure.

Conventional surgery (not laser surgery) for glaucoma (POAG).

Generally reserved for patients whose glaucoma cannot be controlled with eyedrops and laser surgery.

Can lost vision be restored by treatment?

No. Lost nerve fibers will not grow back.

What are "Beta-blocker" eyedrops?

Some glaucoma eyedrops contain “Beta-blocker” medicine. They are absorbed into the blood circulation and may cause shortness of breath in patients with lung or heart conditions. The most common beta-blocker eyedrops are Timoptic and Timoptic-XE. They are excellent anti-glaucoma eyedrops and cause no problems in people with normal heart and lungs.

I have been using Timoptic (or Timoptic-XE) without problems. Recently I was diagnosed with chronic bronchitis (or heart disease). What should I do?

Glaucoma patients on Timoptic who develop chronic bronchitis, asthma, COPD (chronic obstructive lung disease), emphysema or heart problems, should let us know about it. They should also remind their family doctor that they are using beta-blocker eyedrops for glaucoma.

Cost of glaucoma drops.

Glaucoma is a lifetime condition. Over time the cost of drugs is high. You will pay less if you shop around for glaucoma drops. If cost is a major problem, you may consider Laser surgery (SLT). Medical insurance and Medicare cover laser surgery.

How to instill eyedrops.

The proper technique to instill eye drops is very important.
Detailed instructions are on the How To page.

Glaucoma (POAG) - Take home information for our patients

We are committed to inform our patients thoroughly about their condition. A well informed patient will benefit from that knowledge and, over time, will be much better off because of it. With that in mind, we have gathered here for you important information about your type of glaucoma (POAG).

A special note to patients for whom we have prescribed timoptic  or Timoptic- XE:

Timoptic-XE is absorbed into blood circulation. Because it is a “Beta blocker” type of drug, it may cause problems in patients with lung and heart conditions.

If you have now, or have had in the past, or should you develop in the future asthma, COPD (chronic obstructive lung disease), chronic bronchitis, emphysema or heart problems, let us know. Also, remind your family doctor that you are using beta blocker drops for glaucoma.

The complete name of your eye condition is Chronic Primary Open Angle Glaucoma (POAG).This chronic form is usually painless. Rarely, when the pressure within the eye increases markedly, eye pain may develop. When this happens, it must be evaluated promptly. Call us immediately and tell receptionist you have to be seen because you have glaucoma and eye pain.

To understand the loss of vision in glaucoma, you must be aware of the two main types of vision – central vision and peripheral vision. Central vision is the sharp vision you use to read. As you read this letter with your central vision, you are also aware of the room around you. You are aware of the room, and of the rest of the world around you, because you are using your side (peripheral) vision. In glaucoma, you lose your side vision while the reading vision stays sharp. This is why you would not notice vision loss until the loss is very great. To give you an idea of what the loss side vision is like: If you lost your side vision, and you were driving across an intersection, you would be able to read the license plate of the car in front of you but you would not see the bus coming at you from the side. Remember, by the time you notice vision loss, the loss is far advanced. It is too late to do anything about it. The damage cannot be reversed. I cannot emphasize it too strongly – follow recommendations faithfully!

To protect the nerve, the pressure inside the eye has to be brought down to a point where no damage to the nerve will occur. This point varies from patient to patient. Even when the pressure is lowered to what appears to be a reasonable level, in some predisposed people glaucoma may progress. Monitoring of the nerve appearance and of its function must continue, regardless of the pressure achieved

The first step in monitoring is the periodic eye pressure check. If the pressure is higher than “normal” or desirable, the treatment will need to be changed. On the other hand, a finding of “normal” pressure only means that it is normal at that particular time. It does not give us assurance that it is at the desirable levels at all times, day and night (there is variation in pressure during the day and night). To detect progressive nerve damage, periodic eye exams are needed in addition to pressure checks. The nerve head has to be carefully examined and its appearance compared against nerve photographs taken during previous eye exams.

A Nerve Fiber Analysis test (OCT test) may be done in order to obtain a baseline picture against which later tests will be compared. If there is progression of nerve loss on subsequent tests, treatment will be adjusted. The OCT test is currently among the most sensitive tests available for detection and follow up of glaucoma. It is positive early, before the nerve changes appearance, before the Visual Fields test becomes positive and long before you have significant vision loss.

The OCT test measures how many nerve fibers still remain. The Visual Fields test checks the nerve function. These tests measure different aspects of glaucoma damage and both types are necessary for the best glaucoma care.

At each visit you will be told when to come back for another eye exam. Write that date in your calendar. For your 6 month visit we will send you a reminder to schedule your exam. If, for any reason, you do not get a reminder please check your calendar and call us for an appointment anyway.

There is some association between diabetes and glaucoma. It may be prudent to have your doctor check you for diabetes.

Glaucoma tends to run in families. Brothers and sisters of glaucoma patients are 20 times more likely to develop glaucoma than people without family history of glaucoma. Children of glaucoma patients have an almost 10 times greater chance of developing glaucoma.

Your blood relatives should be checked for glaucoma. Measuring the eye pressure is a common screening test for glaucoma, but is not enough. For a variety of reasons it misses up to one half of glaucoma cases. It may be fine for people who are not at high risk for glaucoma (do not have family members with glaucoma). Glaucoma patient relatives need periodic exams with detailed evaluation of the nerve, possibly including the OCT test.

Glaucoma is a lifetime condition. Over time the cost of drugs is high. You will often pay less for drops if you shop around. If cost is a major problem, you may consider laser treatment. Selective Laser Trabeculoplasty (SLT) is a well established, painless, in-office procedure. It is commonly done on patients who do not respond well to eye drops, have problems administering them, tend to forget to use them, cannot tolerate them, or are otherwise unable to comply with eye drops treatment for any reason. Some pregnant women choose the laser procedure to avoid the use of medications during pregnancy. Initially, laser controls the pressure in 4 of 5 patients. The effect may fade with time but, one year after laser surgery, the pressure still remains under control in about one half of patients. SLT surgery is covered by medical insurance and Medicare.

To instill eye drops:

  1. Wash hands
  2. Invert the closed bottle and shake once
  3. Sit down, lean back, tilt your head back, look up toward your forehead
  4. With index finger pull down lower lid to make a pocket for the drop
  5. Hold bottle over the eye between thumb and index finger of the other hand. May rest one finger or thumb against bridge of nose or brow. Do not touch the tip of the bottle with lid or finger.
  6. Squeeze a single drop (extra drops won’t hurt but are wasted)
  7. Press your index finger to the inner corner of the eye for 20-30 seconds to block the tear duct and prevent medication from draining away.


If you are using more than one kind of drops wait at least 2 minutes between drops (to avoid the second drop washing out the first drop).

To prevent contaminating the solution in the bottle do not allow the tip to touch the eye, hand or any other object. This is critical if you also have an eye infection

Soft contact lenses absorb, and are stained by the benzalkonium preservative found in most glaucoma drops. Remove lenses before instilling glaucoma drops. Wait at least 15 minutes before reinserting the lenses.

Cold remedies containing Pseudoephedrine, Phenylephrine or Neo-Synephrin; anti-histaminics Chlorpheniramine, Diphenhydramine or Benadryl and overactive bladder remedies such as Detrol often carry a warning telling you not to use them if you have glaucoma. These warnings do not apply to your type of glaucoma. You can safely use them for a week or two; beyond that, monitoring may be needed.

Steroids (cortisone, hydrocortisone, prednisolone, etc.) tend to increase eye pressure.

If you need to use steroids for longer than 2 weeks, your eye pressure has to be monitored during use. This includes use of steroid-containing eye drops, steroid pills, and steroid creams over large areas of the body. Use of steroid creams for small skin lesions is unlikely to cause increased pressure. If you are taking steroids now, do not discontinue them – just tell us about it and come in for a re-evaluation. Steroid use for less than 2 weeks generally does not require special monitoring of eye pressures.

By following our recommendations, and faithfully complying with monitoring requirements, the chances of preserving your vision are excellent. Because chronic glaucoma has no symptoms, and people are not able to detect loss of vision, some patients are tempted to lower their guard. That’s a big mistake – don’t make it!

I trust that I have anticipated and answered most of your questions. If not, please let me know.

Thank you for choosing Southland Eye Clinic for your eye care.