What is Glaucoma?
Glaucoma is an eye disease where the pressure inside the eye becomes too high resulting in progressive damage to the main nerve of the eye (the optic nerve). This progressive damage initially causes a gradual loss of side vision that is not noticeable until it is very advanced. Untreated glaucoma will eventually cause blindness. Most forms of glaucoma produce no noticeable symptoms until major, irreversible nerve damage has already occurred. This is the real danger of the disease.
However, if diagnosed early, glaucoma is treatable. Therefore, being examined for glaucoma on a regular basis is very important. In addition, if it is determined that you are at high risk for glaucoma or you already have the condition, careful examination, testing, and follow-up care are needed to preserve your sight. The take home message is that vision loss CAN be prevented from glaucoma if caught early. Early detection is the key.
Glaucoma can essentially be thought of as a plumbing problem. The eye has a faucet that is continually making fluid (aqueous humor), and the eye has a drain. Glaucoma is when the drain does not work well enough to keep up with the faucet, and the pressure inside the eye builds up.
Although glaucoma can occur at any age, the risk of developing the disease increases as we age, being most common after 35 - 40 years of age. It is estimated that glaucoma will affect 1 of every 50 adults. Anyone can get glaucoma, but people at higher risk include:
- Those who are significantly near-sighted (high myopia)
- Those with a family history of glaucoma
- Those who have had a significant trauma to an eye (even decades earlier)
- Those who have had major eye surgery
- Those of African descent
However, it is important to emphasize that even low risk patients over the age of 35 should have their eyes examined by their family doctor of optometry for glaucoma at least every two years. Also, testing for glaucoma involves much more than a "pressure check" at a health fair. Many early glaucoma patients have intra-ocular pressures that vary significantly from day to day or even from one hour to the next. It has been estimated that as many as one third of all early glaucoma patients will present to an eye doctor with a "normal" eye pressure. Therefore testing for glaucoma based on intraocular pressure measurements alone will result in a significant number of patients with progressive glaucoma being missed. Bottom line: A "pressure test" is not enough.
How is glaucoma diagnosed?
A thorough eye examination that includes intraocular pressure readings, careful assessment of a patient's side vision (visual field) and optic nerves is essential to diagnose glaucoma early when it is most treatable. At Gainesville Eye Associates, we believe it is important for our patients to have access to leading edge technology and expertise to properly manage their glaucoma. Examples of this technology are the GDx Nerve Fiber Analyzer, the Argon Laser to perform glaucoma laser procedures, the OCT optic nerve analyzer, and the incorporation of pachymetry corneal thickness analysis. These devices give us the most complete amount of information to make diagnostic and treatment protocols of our patients.
How is glaucoma treated?
Glaucoma is usually treated by lowering the pressure in the eye to a level that hopefully stops progressive damage to the nerve. The first line of treatment for glaucoma is usually topical eye drop medications. Fortunately many glaucoma drops have been developed over last few years with several more on the horizon. Glaucoma medications typically work by either reducing the amount of fluid produced inside the eye or by helping intraocular fluid drain out more efficiently. Some medications may actually do both. It is not uncommon to be on two or more medications at one time to treat glaucoma.
Once a patient is on two or more medications and they still need their intraocular pressures lowered more, it is likely they will need laser or other glaucoma surgery to further reduce the pressure in the eye if it is needed. If topical medications and laser treatments fail to lower intraocular pressure effectively, glaucoma surgery is an option. Our doctor performs the latest techniques in glaucoma surgery, offering patients the best likelihood for success in long term eye pressure reduction.
What is Diabetic Retinopathy?
Diabetes is a condition in which the body's ability to process and store sugar has been impaired. Among the characteristics of the disease are gradual changes in blood vessels. Diabetic retinopathy is a complication of diabetes caused by the deterioration of blood vessels nourishing the retina at the back of the eye. These blood vessels become damaged due to persistently elevated blood sugar. The damaged blood vessels can leak blood and fluid resulting in swelling of the retina. This swelling can lead to permanent visual loss.
Who is at risk?
Persons who have had diabetes for a number of years are especially at risk of developing diabetic retinopathy. However, some patients can have evidence of diabetic retinopathy at the time they are diagnosed with diabetes. Six in ten who have had diabetes for over 15 years show symptoms of retinal damage; high blood pressure and pregnancy both worsen the condition. Although diabetic retinopathy is easily detected during routine eye examinations and treatable with laser surgery in early stages, it is the leading cause of new blindness among adults. Diabetics are 25 times more likely to become blind than those without the disease.
Two types of retinopathy
The two types of diabetic retinopathy are background retinopathy and proliferative retinopathy.
In background retinopathy, blood vessels weaken and begin to leak blood and serum. These fluids collect and form deposits in the retinal tissues, causing it to swell. If the leaking blood vessels are in the peripheral area of the eye, no serious visual impairment usually occurs. However, if the fluid collects in the macula - the area of the retina responsible for straight-ahead, detail, and color vision - blind spots and blurred vision can make activities such as reading and driving difficult or impossible.
In the second, and more advanced stage of diabetic retinopathy, the abnormal cells rapidly spread (proliferate) across the inner surface of the retina. These weakened vessels can bleed into the vitreous and stop light from reaching the retina. In addition, the connective scar tissue, which forms as a result of the ruptured blood vessels, can shrink, pulling the retina away from its underlying structure, causing it to detach. Severe loss of sight - even blindness - may result.
What to look for
There is no pain associated with either form of retinopathy. Gradual blurring of vision may occur. But changes in the eye can go undetected without a medical eye exam. When bleeding occurs in proliferative retinopathy, the patient may see spots, a clouding of vision, or experience a complete loss of sight in the affected eye.
Detection and diagnosis
There are numerous instruments and techniques that eye doctors use to examine the retina. The important point is that every person with diabetes needs an annual eye exam to screen for diabetic retinopathy. The exam typically takes about 10 minutes and involves dilating both eyes.
Treatment of retinopathy
Dr. Chapman has extensive experience in diagnosing and treating diabetic retinopathy. He will take into account your age, medical history, lifestyle, and the degree of damage to the retina before recommending a course of action. In many cases, treatment is not required; in others, laser treatments may be recommended to halt further progress of the disease. These laser treatments can be performed in our state of the art office facilities. The laser procedures typically take 10-20 minutes to perform.
In cases of background retinopathy, the laser is focused with pinpoint accuracy on the damaged blood vessels. Heat from the laser seals the vessels and helps bond the retina to the back of the eye by forming small scars.
One common treatment for proliferative retinopathy is called panretinal photocoagulation. In this procedure, the peripheral retina is scattered with laser light beams, like the pattern made by a shotgun. Although a certain amount of healthy tissue is destroyed, this technique usually stops further growth of abnormal cells and preserves the macula, saving valuable straight-ahead and color vision.
Removal of the vitreous
If the vitreous has become too clouded with blood to clear on its own, a surgical procedure called a vitrectomy may be recommended. In this technique, the vitreous is drained and replaced with a clear, artificial solution. An immediate improvement in sight is noted in about 70% of cases.
Retinal detachment occurs when the transparent layer of the retina separates from the wall of the eye. As the retina separates away, vision becomes darkened and distorted. Complete detachment leads to complete loss of vision. Retinal detachment typically requires a vitrectomy or scleral buckle surgery to re-attach the retina.
If you have diabetes, your eyes are at risk for diabetic retinopathy. Early detection and diagnosis of diabetic retinopathy is important if good vision is to be maintained. As there are no symptoms in early stages, regular eye exams are vital. A consultation by Dr. Chapman can ensure quality care for your eyes.
What is the macula?
The thin inner layer of eye is called the retina. It is like the "camera film" of the eye. The central portion of the retina that allows us to see detail vision such as reading and recognizing peoples faces is called the macula. The rest of the retina allows for "side vision" but is not able to distinguish fine detail. A person without good macular function is able to walk around without bumping into things as well as take care of their daily needs such as bathing, cooking, and eating. However, they are unable to read a newspaper, recognized details of a persons face or see highway signs while driving.
What is macular degeneration?
Macular degeneration is a deterioration of the deepest layers of the retina in the area of the macula. The actual cause of macular degeneration is under intense study but it is usually associated with the aging process. The deterioration appears to be related to a build up of oxidants and other metabolic waste products in the pigmented layer of the retina.
Over time this layer begins to degenerate and form what are called drusen. As more drusen form, macular function decreases and vision begins to blur. In some cases the pigmented layer undergoes atrophy. Small gaps (scotomas) in vision develop and eventually enlarge to cause more severe vision loss. Drusen development and/or atrophy of the pigmented layer of the macular is called dry macular degeneration.
In the most severe form of macular degeneration small breaks in the layer between retina and the vascular middle layer of the eye (choroid) can develop. These breaks allow abnormal blood vessels to develop and grow underneath the retina. These vessels (subretinal neovascular membranes) hemorrhage and scar causing fairly rapid and severe loss of macular function and central vision. This is called wet macular degeneration.
Treatment for dry macular degeneration consists of vitamin supplements and close surveillance for visual changes. The AREDS vitamin formula is available over the counter and can reduce the risk of dry macular degeneration progressing to the wet form.
The wet form of macular degeneration has many new treatments recently approved by the FDA. These treatments range from lasers to medications injected in or around the eye.
Macular degeneration is a difficult disease but with motivation and patience its effects can be significantly reduced. Early treatment and preventative measures can help slow down the condition and low vision rehabilitation can help people to lead an independent life style.