Don’t Let the Dark In. Make Sure You Are Getting the Glaucoma Care You Need.
What is Glaucoma?
Protecting Your Vision
How Does Glaucoma Develop?
How Does Glaucoma Cause Loss of Vision?
Types of Glaucoma
Glaucoma Detection and Diagnosis
What is Glaucoma?
Glaucoma is a group of diseases that cause increased pressure in the eye which can damage the eye’s optic nerve and result in vision loss and blindness. Glaucoma affects more than three million Americans. However, approximately half of these individuals don’t even know they have the disease and many will be diagnosed only when it’s too late to save vision. Glaucoma is called the “silent thief of sight” because patients experience no pain, no noticeable symptoms, and there is no cure. The good news is that glaucoma can be controlled and vision can be preserved if the condition is detected early. Dr. John Samples is a fellowship-trained glaucoma specialist who has the knowledge and expertise to help you manage and treat your glaucoma.
Protecting Your Vision
Studies have shown that the early detection and treatment of glaucoma, before it causes major vision loss, is the best way to control the disease. If you fall into one of the groups at high risk for the disease, make sure to have your eyes examined through dilated pupils every one to two years at Olympia Eye Clinic.
Help protect your vision and the vision of your relatives and friends. People over 60 years of age, people with relatives that have glaucoma, and African Americans over the age of 40 run a high risk of having glaucoma.
How Does Glaucoma Develop and Cause Loss of Vision?
In order to understand how glaucoma develops, it is important to understand how all the parts of the eye’s anterior chamber work together. The anterior chamber is a small space in the front of the eye between the cornea and the iris (the colored part of the eye). The hole in the iris is called the pupil. Behind the iris and the pupil is the lens. The anterior chamber is filled with a fluid called the aqueous humor, which brings oxygen and nutrition to the lens and cornea, and also removes waste products.
A tiny organ called the ciliary body, which is located behind the iris, continuously produces the aqueous humor. From there the aqueous flows forward through the pupil and enters the anterior chamber. Like air pumped into a tire, the aqueous keeps the eye “pumped up” to just the right pressure. The pressure inside the eye is called the intraocular pressure. The right amount of pressure depends on the correct balance of aqueous fluid going into, and the ease with which it flows out of, the anterior chamber. The aqueous humor empties out of the eye through a special drain located in the corner, or angle, where the cornea and iris meet in front of the iris. This drain is called the trabecular meshwork.
The balance between the amount of aqueous fluid produced and the amount removed through the trabecular meshwork is very important. If too much aqueous is being made, if it cannot drain fast enough, or if the drain is not working properly, the pressure inside the eye will rise. The pressure in the eye can never rise so high that the eye will burst, but it can rise high enough to damage the optic nerve and cause loss of vision. This condition is called glaucoma.
How Does Glaucoma Cause Loss of Vision?
The loss of vision from glaucoma is caused by damage to the optic nerve. Once vision is lost it cannot be restored. Glaucoma truly supports the old adage that “an ounce of prevention is worth a pound of cure”. Glaucoma treatment options are aimed at stopping or slowing the loss of vision by lowering the pressure in the eye. As glaucoma progresses, the optic nerve loses nerve fibers, resulting in a larger and larger empty indentation called the “cup”.
Types of Glaucoma
There are two basic kinds of glaucoma: open angle glaucoma and narrow angle (closure) glaucoma.
In open angle glaucoma, the aqueous fluid cannot drain out of the eye properly because the trabecular meshwork is not working properly. As fluid builds up in the eye, the pressure rises. This pressure can cause irreversible damage to the optic nerve, which can lead to loss of vision.
In narrow angle glaucoma, the iris is pushed against the cornea so that the aqueous cannot even get to the drain. In angle closure glaucoma, the drain, the trabecular meshwork, is physically blocked by the iris. This can cause the intraocular pressure to rise dramatically.
Glaucoma Detection and Diagnosis
As we examine your eyes to ascertain whether or not you have glaucoma, we will carefully evaluate five crucial factors: the pressure in the eye, the health of the optic nerve, your visual field, the health of the retinal nerve fiber layer, and the thickness of your cornea.
The normal intraocular pressure in the eye is between 10 and 20mmHg (millimeters of mercury). However, there is not a hard and fast relationship between pressure readings and glaucoma. Many individuals appear to tolerate elevated pressures for years, while others suffer damage even at “normal” pressures. Nonetheless, studies show that the higher the pressure, the greater the chance that the patient has or will develop damage to the optic nerve. One of the most important facts about open angle glaucoma is that the rise in pressure inside the eye usually occurs very gradually, over a period of several months or years. Because the pressure builds up gradually, it causes no pain, redness, blurred vision, or other symptoms. Therefore, patients in the early or middle stages of open angle glaucoma have no way of knowing that they have glaucoma, unless they are examined regularly.
The loss of vision from glaucoma is caused by damage to the optic nerve. As glaucoma progresses, the optic nerve loses nerve fibers, resulting in a larger and larger empty indentation called the “cup.” A dilated comprehensive exam will allow your doctor to see the optic nerve and determine how healthy it looks.
Traditionally, the early loss of vision in glaucoma is thought to be a dimming of the peripheral field of vision. Such loss can be insidious, sneaking up on the patient until the (irreversible) damage is quite severe. What’s even worse is that in some patients glaucoma will very rapidly cause loss of vision that encroaches very close to the patient’s central view of the world. An essential part of a glaucoma evaluation is a thorough assessment of the “visual field,” performed with our state-of-the-art Humphrey static threshold perimeters.
Retinal Nerve Fiber Layer
Olympia Eye Clinic uses an advanced imaging technique called retinal tomography to visualize the retinal nerve fiber layer. Using a state-of-the-art Heidelberg Retinal Tomographer (HRT), photographs of the optic nerve and surrounding retina are taken and a detailed three-dimensional image is compiled.
Corneal thickness is important because it can prevent accurate measurement of intraocular pressure. Patients with thin corneas may have higher actual intraocular pressures than what is recorded and patients with thick corneas may have lower actual intraocular pressures than what is recorded. Corneal pachymetry is a quick and painless test that measures the thickness of your cornea. This measurement will allow your doctor to better evaluate your intraocular pressures and develop an appropriate treatment plan.
High pressure, optic nerve damage, or reduced visual field can occur in a patient who does not, in fact, have glaucoma. But when two or three or these conditions are present in the same person, the diagnosis of glaucoma becomes more likely. In advanced cases of glaucoma, the pressure inside the eye can be quite high and there is a significant loss of tissue in the optic nerve, as well as loss of peripheral vision. Remember that in open angle glaucoma the patient can have all of these conditions for many, many years before he or she notices anything or feels that something is wrong.
For the majority of patients with glaucoma, careful diagnosis, treatment, and long-term professional care can prevent or delay loss of vision. All patients over the age of 40 should have an eye examination that not only measures vision but also measures the intraocular pressure and examines the retina and the optic nerve every one or two years. If glaucoma is detected, several treatment options are available, including eye drops, oral medication, Argon Laser Trabeculoplasty (ALT), Selective Laser Trabeculoplasty (SLT), Cyclophotocoagulation laser treatment, trabeculectomy surgery, and glaucoma shunt surgery. Depending on the type of glaucoma and other factors, one or more of these treatments may be utilized to provide safe, effective relief.
To learn more about glaucoma or to speak with a specialist about glaucoma treatment options, call us at 360-456-4800 to schedule a consultation.
How did I get glaucoma?
Unless you had a specific injury or disease, you were simply born with a tendency to develop glaucoma, and it has developed progressively throughout your life.
Do I have to watch my diet?
In some patients, excessive caffeine intake will elevate the intraocular pressure.
Can I take cold and allergy medications?
Many such medicines carry warnings about use by patients with glaucoma. These warnings are directed at patients with untreated narrow angle glaucoma, and for the most part do not apply to patients with open angle glaucoma (or patients who have had peripheral iridectomies for their angle closure glaucoma).
How does my blood pressure affect my glaucoma?
Some blood pressure medicines will also lower eye pressure. People with very low blood pressure may develop glaucomatous optic nerve damage even with “normal” eye pressure.
Does stress or tension cause the intraocular pressure to go up?
If you respond to stress by consuming large amounts of caffeine, it may raise your eye pressure. Stress or tension by themselves do not raise intraocular pressure.
Will I be able to feel it when my pressure is high?
Pressures in the range that causes damage for most patients with open angle glaucoma is not symptomatic. This is why regular testing and comprehensive dilated exams are vital for people at risk for glaucoma.
Are cataracts and glaucoma similar or related?
Cataracts (a clouding of the lens) and glaucoma are both diseases that tend to occur more in older individuals, and they both affect the front of the eye. There are many patients who have cataracts and glaucoma at the same time. Cataract surgery often results in lower eye pressure, and more easily controlled glaucoma.
How will glaucoma eye drops affect my vision?
Many drops have no effect on vision. Some glaucoma drops, such as pilocarpine, tend to affect the vision in particular patients. When you are given drops for glaucoma treatment, your doctor will check to see if they lower the pressure, if they affect your vision, and if there are any undesirable side effects.
Will eye drops, glaucoma laser surgery, or conventional glaucoma surgery improve my vision?
Treatment for glaucoma rarely, if ever, improves vision. The goal of glaucoma treatment is to lower the intraocular pressure and prevent further loss of vision. No treatment can restore vision once it has been lost because of glaucoma.
If I have laser surgery, will I still need the glaucoma drops?
Whether we are adding a second or third drop to your regimen, or adding laser treatment, our goal is to adequately control your pressure and preserve your vision, rather than to “get you off drops.” Approximately one out of four patients can stop using eye drops after glaucoma laser surgery.
Are Trabeculectomies and Glaucoma Shunt surgeries safe?
All surgery carries some risks. Glaucoma surgery is no exception. Because incisional surgeries such as trabeculectomies and glaucoma shunt surgery carry considerably more risk than other treatment options like drops and laser procedures, we will endeavor to control your glaucoma through the safest means possible. Regardless of the surgeon who performs these procedures, these surgeries will invariably lead to an acceleration of cataract formation (perhaps requiring a second surgery), and the risk of infection, hemorrhage, severe inflammation, and other complications is quite high. Accordingly, all other options should be exhausted before resorting to these procedures. Your Olympia Eye Clinic Physician will explain all of the risks and benefits of glaucoma surgery.
If I have glaucoma does that mean that I will eventually go blind?
Although glaucoma can cause blindness especially if neglected, with early detection and timely care nearly everyone with glaucoma can retain good vision.
Is there a permanent cure for glaucoma?
Generally, there is no permanent cure for glaucoma. In some patients, glaucoma surgery can reduce the intraocular pressure to normal levels without medicines indefinitely, but it is still important for all patients with glaucoma to continue a lifelong program of regular visits to Olympia Eye Clinic to make sure that the glaucoma stays under control.