Glaucoma

About Glaucoma

Because the symptoms of glaucoma can be mild, or even non-existent, regular screenings are important. it is recommended that individuals get a baseline screening done at the age of 40.

Who Is At Risk?

People most at risk are:

What Is Glaucoma?

Glaucoma is a group of diseases where the fluid inside the eyeball gradually builds up and causes damage to the optic nerve. The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina, the light-sensitive layer of tissue at the back of the eye to the brain. A healthy optic nerve is necessary for good vision.

The eye is like a sink that is filling up with water with a closed drain and if you were to place a flexible cover over the sink, the cover will start the bulge outward as it filled with water. Likewise, this is what happens to the inside of the eyeball with glaucoma.

The eye normally drains this build up of fluid through a network of tissues called the drainage channels, which are located between the iris and the cornea. However, in glaucoma theses channels do not function properly and the pressures continue to build up in the eyeball. This build up of pressure will reduce the blood flow to the retina and the optic nerve. Without suitable blood supply, the fibers of the optic nerve will die and vision loss will result.

Glaucoma is called the "sneak-thief of sight," which means that it steals sight without warning and without symptoms. If it is left untreated it can lead to permanently impaired vision or blindness. It is an irreversible disease that can strike at anytime, and when symptoms are finally detected, it may be too late for some 

Causes of Glaucoma

 The most common type of glaucoma (Primary Open-Angle Glaucoma) occurs when the channels draining the fluid in the eye become clogged and do not work correctly. This blockage can gradually increase pressure within the eye to damaging levels. Generally there is no pain which occurs, so a person is usually unaware that anything is happening. There are no signs and symptoms initially, but over the years, if left untreated, the vision will slowly be lost; starting in the periphery and moving toward the central vision.

With early treatment, you can help protect your eyes against serious vision loss and or blindness. Regular eye examinations from your doctor are the best way to detect glaucoma. Glaucoma affects about 3 million Americans-half of who don't know they have anything wrong.

When eye pressure builds up rapidly, it is called Acute Angle Closure Glaucoma. This type of glaucoma commonly occurs in individuals who have narrow drainage channels in their eyes, also called narrow angles. If an attack of this type of glaucoma happens, the fluid behind the iris cannot pass through the pupil, thus pushing the iris forward, preventing any drainage through the angles of the eye.

It is as though a piece of plastic is floating near a drain and suddenly drops over the opening and blocks the flow out of the sink. In cases of Acute Angle Closure Glaucoma, a person may have blurred vision, halos around lights, deep pain behind the eye, nausea and vomiting. If you have any combination of these symptoms, call your eye doctor immediately. If pressure within the eye is not immediately relieved, blindness may result in a matter of hours.

How Glaucoma is Detected

A glaucoma diagnosis is based upon several factors, such as what the optic nerve looks like, what the pressure is, and whether there is damage to the vision. A common misconception about glaucoma is that if a person has high pressures in the eyes, then they have glaucoma. This is not always true. The high pressure is a risk factor for glaucoma, but does not always mean that you have it.

Whether or not you can get or have glaucoma depends on the level of pressure that your optic nerve can tolerate without being damaged. This level is different for each person.

Although normal pressure is usually between 12 - 21 mm Hg, a person might have glaucoma even if the pressure is in that range.

Types of Glaucoma & Symptoms

There are two categories of glaucoma, acute & chronic. The chronic form is the most common and treatment is normally in the form of eye drops. The acute form is rare but if it does occur, immediate treatment should be sought to prevent permanent loss of vision.

The Chronic does not have any symptoms until it is in an advanced stage, which is why it is important to have your eyes checked regularly. But in the acute form the early symptoms to watch for are blurred vision, loss of peripheral vision, halos of lights, nausea and vomiting. The acute form is sometimes treated through the use of a laser, by creating a small opening in the iris to relieve the pressure, or by making a drain in the eye to relieve the pressure, called a Trabeculectomy.

There are many types of glaucoma within these two categories. Such as, Primary Open Angle Glaucoma, Chronic Angle Closure Glaucoma, Normal Tension Glaucoma, Pseudoexfoliative Glaucoma, Pigmentary Glaucoma, Neovascular Glaucoma, Secondary Glaucoma, Traumatic Glaucoma, Congenital Glaucoma, and Mixed Mechanism Glaucoma. 

Diagnostic Testing

HRT Nerve Head Scanning

The Heidelberg Retinal Tomogram (HRT II) is used to perform a scan of your optic nerve if you have or are suspected of having glaucoma. By repeating this test approximately every year, it is possible to detect progressive damage from glaucoma, oftentimes before any changes would be noticed on visual field testing or by the patient. This sophisticated software can be the most sensitive test to determine if someone is beginning to develop glaucoma or if they already have glaucoma, and can tell if their glaucoma is progressing and may need a change in treatment.

Pachymetry

Pachymetry is the measurement of the thickness of the cornea, the clear layer on the front of the eye. It is an important measurement in a person who has glaucoma or is a glaucoma suspect. When the cornea is thinner than average, patients appear to have an increased risk of developing glaucoma. In addition, patients with unusually thick corneas, are more likely to have higher intraocular pressure readings (IOP) but not develop glaucoma; a condition known as ocular hypertension.

There are two explanations that have been put forward to explain why patients with thin corneas are at higher risk for glaucoma progression. Firstly, the "gold standard" device for measuring intraocular pressure, the Goldmann Applanation Tonometer, is calibrated for the "average" thickness cornea. If a patient has a thin cornea, then the true pressure inside the eye is higher than what this device is recording. Secondly, when the cornea is thin, it is more likely that the other support structures of the eye, such as those surrounding the optic nerve are also thin and more prone to getting damage to the nerve itself or its blood supply.

Visual Field Testing

Visual field testing is a test of your optic nerve function, whereas the HRT nerve scan measures your optic nerve form.

The visual field tests' your peripheral vision and maps out any damaged areas by having you look straight ahead at a darkened background and have you click a button every time you see a light appear somewhere in the machine. The machine actually tests many points in your field of vision with different intensities of light to determine the faintest light that you can still see at any given point and produces a visual field map of these results. There are certain patterns that

are characteristic of damage from glaucoma. If these patterns of missing light correspond with areas that show structural change on your HRT nerve scan and clinical examination of your optic nerve, then this would suggest that your glaucoma is not stable and a change in treatment would be needed.

How Glaucoma Is Treated

Glaucoma is treated with medications, laser surgery, and invasive surgery in the operating room.

Eye Drops

There are various types of medications that can be used, which work in one of two ways. One type decreases the amount of fluid that is produced inside the eye and the other type helps the drainage channels in the eyes to function better. Glaucoma drops may be taken once or several times a day.

If the Drops are not efficient enough to control the pressure, the doctor may suggest a surgery.

Selective Laser Therapy (SLT)

There are many types of surgery for glaucoma. The two most common Laser Trabeculoplasty are Selective Laser Trabeculoplasty (SLT) and a more invasive surgery called a Trabeculectomy. The SLT is a laser surgery which increases the outflow of fluid from the eye to decrease eye pressure. This surgery is done most often in conjunction with taking medications and is an alternative to adding another eye drop. Typically only one half of the drainage channels in the eye are done at a time, so you may have the laser surgery done twice if the need arises. The laser works very well to decrease eye pressure inside your eye, however after several months or years the effect may wear off and other options may need to be pursued.

The following is what to expect when undergoing a laser procedure. Topical anesthetic drops will be instilled, which will numb your eye. When the doctor performs the laser procedure you will be sitting in an exam chair with your chin placed in a chin rest and your forehead firmly against the headrest.

The Doctor will need to place a special lens upon your eye, which helps to focus the laser light.

The laser light is a high energy beam that when aimed into the lens, it reflects into the drainage channels inside the eye. Normally there are 50-100 laser spots made inside the drainage channels that help the fluid within your eye move through them more efficiently.

During the laser you may see flashes of bright lights and it may sting a little, but this is normal.

After the procedure the doctor will provide you with some eye drops to help control any inflammation that may be caused by the laser. These drops are generally taken four times a day for four days.

A few days following the procedure the doctor will call you back to the office to check your eye pressure and make sure that you are doing well.

Trabeculectomy 

More sophisticated surgeries in the operating room may need to be done in the even that they eye drops and laser surgeries are not effective in controlling the pressure. The most common surgery done to control the pressure is to make a drain in the eye also called a Trabeculectomy.

This surgery allows for a new opening to be made inside the eye into which fluid can drain out. The surgery will create a "bubble" under the eyelid, which will act like a trap door to let the fluid escape into the drain and then evaporate to the outside of the eye.

This surgery is performed at an outpatient surgery center and the anesthetist will be there to sedate you and keep you comfortable. Small injections around the eye socket are given to numb the eye and the surrounding area.

In the procedure the doctor will remove a tiny piece of tissue in the sclera (white portion of the eye) under your eyelid. By doing so it creates a new passageway for fluid to leave the eye, but it does not leave a hole in the eye. This area is covered by the conjunctiva, which is the clear tissue covering the outside of the eye.

After the surgery you will be instructed to use two or three different eye drops to protect against infection and inflammation, these will be used for several weeks following the surgery. Also after the surgery the old eye drops you have will not be used in that eye unless the doctor specifically instructs you to use them. You will also need to make a trip to doctors' office roughly once a week for four to six weeks so that the doctor can monitor your eye. This is especially important in the first few weeks

This surgery is about 90% effective at lowering the pressure in the eye. However, the body does have a tendency to scar shut an opening that is made in the body and if it succeeds in closing the drain, a second surgery may be required.

It is very important to remember that this type of surgery is only meant to control the pressure and not to improve your vision.

It is important to realize that this is a surgery like any other, and there may be complications. Some of these complications include: inflammation, infection, swelling in the eye, retinal detachment, and possible loss of sight. This is why it is important to keep your appointment after the surgery, so that the doctor can start treatment if you do have a complication.

Living with Glaucoma

When making the adjustment of having glaucoma, it is important to remember that most glaucoma cases are controlled and managed with the use of medications and/or surgery.

It's important to take good care of your eyes by remembering to take your glaucoma medications daily and it is also essential to be aware that there is another side of glaucoma, which is the emotional and psychological effect that it can have on you.

It is important to talk about how you feel. When you are initially diagnosed with thi disease, it can be beneficial to voice your concerns to someone you trust. You can talk to your spouse, children, siblings, friends, or clergy members. It is also beneficial to speak with others who have glaucoma and share your experience with them about living with this disease. It can be very useful and reassuring.

With proper treatment, glaucoma doesn't have to become a limiting condition. You can still enjoy living life as you did before you were diagnosed and continue to look forward to whatever is next.

Find a specialist you trust and be assured that there are people out there who are working to develop a cure and who keep searching for a better way to care for you as a glaucoma patient.


Commonly Asked Questions

Q. What is glaucoma?

A. Glaucoma is a group of eye diseases that gradually steals the sight without warning and often without symptoms. Vision loss is caused by damage to the optic nerve, which is the nerve which connects the eye to the brain. It was once thought that high intraocular pressure (IOP’s) were the main cause of this damage. We now know that other factors are also involved since people with “normal” IOP’s can experience vision loss from glaucoma. Glaucoma is a chronic disease. It must be treated for life.

Q. What are the symptoms of glaucoma?

A. There are no symptoms for glaucoma in the initial stages. The vision stays the normal and there is no pain. But when the glaucoma progresses to an advanced stage, symptoms will begin. These generally include not seeing objects or even people peripherally (to the side), even though they may see things clearly in front of them. At this stage blurry or worsening vision may occur, it may be difficult to adjust to lighting changes, and the vision may appear to be tunnel-like.

Q. Can anything be done to prevent glaucoma? 

A. No. There is nothing that can stop a person from getting glaucoma, although by starting treatment early the disease can be slowed down. This is why regular eye exams are important. To detect glaucoma the doctor will perform different tests, these include; checking the pressure inside your eyes, dilating your eyes, visual field tests, checking the drainage channels inside your eyes, and doing scans on the optic nerve. These tests will detect any change in your condition. If you are diagnosed early, then the glaucoma is most likely to be controlled with medication or simple laser surgery. 

Q. Will I go blind if I have glaucoma? 

A. Glaucoma can cause blindness if left untreated, which is why it is so important to have regular eye check-ups. If you use your medication correctly and do not skip doses, then it is possible to stall or slow down the disease. In fact your eyesight may out-live you.

Q. If my family members have glaucoma, will I get it? 

A. It does not mean that you will glaucoma, but it means that your risk of getting it is increased. 

Q. What are the risk factors for glaucoma? 

A. If a family member has it, being over 50 years old, being over 40 years old and of African American decent, having a history of a serious eye injury, taking steroid medications, having diabetes, being highly nearsighted, and having high blood pressure. If anyone has these risk factors they should have their eyes checked regularly with an emphasis on looking for glaucoma.

Q. Can Glaucoma be treated?

A. Yes it can. Presently there is no cure for glaucoma but it can be controlled with proper treatment.  Glaucoma treatments include: medications, laser surgeries, and surgeries in the operating room.

Q. Are treatments for glaucoma effective? 

A. Yes. There are various types of medications that can be used, which work in one of two ways. One type decreases the amount of fluid that is produced inside the eye and the other type helps the drainage channels in the eyes to function better. Glaucoma eye drops may be taken once or several times a day. Most people have no problems using the medications, but something to remember about medications, even eye drops, is that they can affect the entire body, not just the eye. So if you notice any side effects, be sure to alert your doctor. In addition, tell your doctor about any other medications you may be taking before you begin glaucoma treatment. The treatments for people in whom the medications do not work to sufficiently control the pressure in, are surgeries. The first type of surgery is done in people who are not in an advance stage of the disease. It is a laser surgery, called a Trabeculoplasty, which helps the drainage channels in the eyes to work better. This is usually done in the doctor’s office. The next surgery is done in the operating room and is the most common invasive surgery done for glaucoma. It is called a Trabeculectomy, in which the doctor makes a drain in your eye to decrease the pressure. After both of these procedures, patients may still need to take eye drops to keep the pressure low.

Q. Is marijuana an effective and legal treatment?

A. In the 1970’s some studies were done which showed that smoking marijuana could lower a person’s eye pressure. The National Eye Institute and the Institute of Medicine have done some more recent studies that show there is no scientific evidence that marijuana works better than the current medication which are available. As for legality, there have been political battles to legalize marijuana for medicinal purposes, including treatment of glaucoma. There have been a few states that have legalized marijuana for medicinal purposes, but it is against the federal law for any doctors to prescribe it. 

Q. Will I still be able to drive if I have glaucoma? 

A. As long as a person can pass the DMV’s tests, most people can still drive. It will depend on how much vision has been affected by the disease. Some people who have advance glaucoma can still drive legally but with restrictions on their license. 

Q. Can I still wear contact lenses?

A. Most likely yes. It depends on what treatment you will need. If only eye drops are needed then you can wear contact lenses, although you will need to remove them to put your drops in and then wait 15 minutes before putting your lenses back in. If you do not remove your contact lenses the eye drops will rapidly decrease the life of your contacts.

Q. How can I help my parent(s) if they have glaucoma? 

A. Many times when a person grows older they are dealing with a lot of health problems that come with age and learning that they could lose their sight is scary. Many people are afraid of becoming a burden to their family if they go blind. One thing to do to help them is to encourage them that many people have kept their vision with the proper care and treatment. Next you can ask if there is something that you can do to help them with their medications or even help them with transportation to their appointments. The most important thing you can do though is to support and reassure them.