For Patients - Specific Retinal Diseases

What is macular degeneration?
Macular degeneration is a deterioration or breakdown of the macula. When the macula does not function properly, the central vision can be affected by blurriness, dark areas or distortion. Macular degeneration affects the ability to see near and far, and can make some activities, like threading a needle or reading, difficult or impossible.

What causes macular degeneration?
Among the various macular diseases, the most common form of macular dege neration is age-related macular degeneration (AMD). Macular degeneration is the leading cause of severe vision loss in people over 50. The two most common types of AMD are “dry” (atrophic) and “wet” (exudative) AMD.

What is new in the treatment of macular degeneration?
South Bay Retina is one of the first practices to offer MACUGEN, a new intravitreal injection drug for the treatment of macular degeneration.

This revolutionary new drug targets vascular endothelial growth factor (VEGF) in the retina to decrease vascular permeability and inflammation which contributes to the progression of wet AMD. Visudyne, a light activated drug, is injected into the bloodstream and travels to the abnormal blood vessels. It is activated by a laser which corrects the abnormal vessels withour causing damage to the retinal tissue. Among other treatments are thermal laser and photodynamic therapy, which are done in the office.

Macular degeneration is a disease that should be treated early. It is also a chronic disease that needs regular treatment over a period of time. With early detection and treatment by a retinal specialist, irreversible vision loss can be minimized.

Age related macular degeneration (AMD) is one of the most common causes of poor vision after age 60. Although the specific cause is unknown, AMD seems to be part of aging. While age is the most significant risk factor for developing AMD, heredity, blue eyes, high blood pressure, cardiovascular disease, and smoking have also been identified as risk factors. AMD accounts for 90 percent of new legal blindness in the US.

Nine out of 10 people who have AMD have the dry form, which results in thinning of the macula, the area of the retina responsible for central vision. Dry AMD takes many years to develop. Currently there is no treatment.

The wet form of AMD occurs much less frequently (one out of 10 people) but is more serious. Laser surgery is the only proven effective treatment, to date, for wet AMD. The procedure usually does not improve vision but prevents further loss of vision. The visual symptoms of AMD involve loss of central vision. While peripheral vision is unaffected, one loses the sharp, straight-ahead vision necessary for driving, reading, recognizing faces, and generally looking at detail. Imagine being able to see a clock on the wall but unable to make out the time or unable to read because you could not see parts of words on the page. Promising AMD research is being done on many fronts. In the meantime, high-intensity reading lamps, magnifiers and other low-vision aids help people with AMD make the most of remaining vision.

More on Dry AMD - PDF

You probably know high blood pressure and other vascular diseases pose risks to overall health, but you may not know that they can affect eyesight by damaging the veins in the eye. Central retinal vein occlusion (CRVO) blocks the main vein in the retina, the light-sensitive nerve layer at the back of the eye. The blockage causes the walls of the vein to leak blood and excess fluid into the retina. When this fluid collects in the macula-the area of the retina responsible for central vision-vision becomes blurry. Floaters in your vision are another symptom of CRVO. When retinal blood vessels are not working properly, the retina grows new fragile vessels that leak blood into the vitreous, the fluid that fills the center of the eye. Blood in the vitreous clumps and is seen as tiny dark spots, or floaters, in the field of vision. In severe cases of CRVO, the blocked vein causes painful pressure in the eye. Retinal vein occlusions commonly occur with glaucoma, diabetes, age-related vascular disease, high blood pressure, and blood disorders. The first step is finding what is causing the vein blockage. There is no cure for CRVO. Your ophthalmologist may recommend a period of observation, since hemorrhages and excess fluid often subside on their own. Laser surgery may be effective in preventing further bleeding into the vitreous, or for treating glaucoma, but it cannot remove a hemorrhage or cure glaucoma once it is present.

Central serous retinopathy is a small, round, shallow swelling that develops on the retina, the light sensitive nerve layer that lines the back of the eye. Although the swelling reduces or distorts vision, the effects are usually temporary. Vision generally recovers on its own within a few months. In the initial stages of CSR, vision may suddenly become blurred and dim. If the macula-the area of the retina responsible for acute central vision-is not affected, there may be no obvious symptoms. CSR typically affects adults between the ages of 20 to 50. People with CSR often lose their retinal swelling without treatment, and recover their original vision within six months of the onset of symptoms. Some people with frequent episodes may have some permanent vision loss. Recurrences are common and can affect 20 to 50 percent of people with CSR. While the cause of CSR is unknown, it seems to occur at times of major personal or work related stress. As CSR usually resolves on its own, no treatment may be necessary. Sometimes laser surgery can reduce the swelling sooner but there is no evidence this improves the final visual outcome. If retinal swelling persists for over three to four months or if an examination reveals early retinal degeneration, laser surgery may be helpful.

What is the retina?
The retina is a neural layer lining the back of your eye that senses light and sends images to your brain. A retinal detachment occurs when the retina is pulled away from its normal position. Vision becomes blurred. A retinal detachment is a very serious problem that almost always causes blindness unless it is treated.

What causes a retinal detachment?
As we age, the vitreous may pull away from its attachment to the retina at the back of the eye. If the vitreous pulls hard enough to tear the retina in one or more places, fluid may pass through, lifting the retina off the back of the eye (see Floaters and Flashes).

What treatment is needed for a detached or torn retina: Types of surgery?

Most retinal tears need to be treated with laser surgery or cryotherapy (freezing), which seals the retina to the back wall of the eye.

There are several ways to fix a retinal detachment. The decision of which type of surgery and anesthesia to use depends upon the characteristics of your detachment.

In each of the following methods, your ophthalmologist will locate the retinal tears and use laser surgery or cryotherapy to seal the tear.

Other possible treatments include a scleral buckle or pneumatic retinopexy. When using the scleral buckle treatment, a flexible bacnd (scleral buckle) is placed around the eye to contract the force pulling the retina out of place. The ophthalmologist often drains the fluid under the retina to its normal position against the back wall of the eye, either internally or externally. When using the pneumatic retinopexy treatment, a gas bubble is injected into the vitreous space inside the eye. The gas bubble pushes the retinal tear closed against the back wall of the eye. Your ophthalmologist will ask you to maintain a certain head position for several days. The gas bubble will gradually disappear.

What are floaters and flashes?
When a person sees small specks or clouds moving in their field of vision, they are called floaters. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear jelly-like fluid that fills the inside of the eyes. Flashes look like flashing lights or lightening streaks.

What causes floaters and flashes?
Floaters are related to Posterior Vitreous Detachments (when the vitreous gel pulls away from the back wall of the eye). PVD is more common for people who are nearsighted, have undergone cataract operations, have had YAG laser surgery of the eye or, have had inflammation inside the eye. Flashes occur when the vitreous gel rubs or pulls on the retina.

Additional Treatment Information: Floaters and Flashes

Although the floaters appear to be in front of the eye, they are actually floating in the vitreous fluid inside the eye. What you see are the shadows they cast on the retina. Because a retinal exam is required to detect a tear, call your ophthalmologist if a new floaters suddenly appears.

Flashes of light can appear off and on for several weeks or months. As we grow older, if is more common to experience flashes. If you notice the sudden appearance of light or flashes, your ophthalmologist should be contacted immediately.

Both doctors and the public have shown growing interest in the relationship between diet and health. Good nutrition depends on a healthy mixture of proteins, carbohydrates, fats, vitamins and minerals. Protein is needed for the building blocks and chemical machinery of our bodies; carbohydrates are needed for immediate fuel and energy; fats are needed for long-term storage of fuel and energy. Vitamins are organic compounds that our bodies cannot manufacture but are essential for maintaining good health. The eye, like any other part of the body, benefits from a healthy diet. Although the exact causes of macular degeneration are not understood, there is some evidence that vitamins and minerals may play a preventive role.

Macular degeneration is damage or breakdown of the macula, the small part of the retina responsible for central vision. It affects both distance and close vision and can make some activities-like threading a needle or reading-very difficult or impossible. Macular degeneration is the leading cause of severe visual loss in people over 65. Zinc, one of the most common minerals in our body, is very concentrated in the eye, particularly in the retina and macula. Zinc is necessary for the action of over 100 enzymes, including chemical reactions in the retina. Studies show some older people have low levels of zinc in their blood. Because zinc is important for the health of the macula, some think that supplements of zinc in the diet may slow down the process of macular degeneration. Scientific studies are not complete and there is no agreement concerning the value of zinc supplements. It is possible that too much zinc may interfere with other trace minerals such as copper. Normal chemical reactions from light in the eye activate oxygen that may cause macular damage. Some vitamins function as antioxidants that work against this activated oxygen. It may be claimed that antioxidant vitamins (vitamins A, C and E) can help slow down macular degeneration and other aging problems. As in the controversy over zinc, there is no agreement that these antioxidants actually help macular degeneration. The first step to overall good health is a balanced diet. Vitamins and minerals are commonly given as supplements to the diet in amounts determined by recommended daily allowances. These supplementary dosages cause no apparent harm and are commonly available. Large doses of vitamins, called therapeutic doses, in amounts many times the recommended daily allowances, may not be completely safe. Nutrition and macular degeneration is still being researched. Consultation with your ophthalmologist before beginning to take therapeutic doses of any vitamin or mineral is advisable.

Macular edema is swelling of the macula, the small area of the retina responsible for central vision. The edema is caused by fluid leaking from retinal blood vessels. Central vision, used for reading and other close detail work, is affected. Because the macula is surrounded by many tiny blood vessels, anything affecting them, such as a medical condition affecting blood vessels elsewhere in the body or an abnormal condition originating in the eye, can cause macular edema. Retinal blood vessel obstruction, eye inflammation, and age-related macular degeneration have all been associated with macular edema. The macula may also be affected by swelling following cataract extraction, though typically this resolves itself naturally. Treatment seeks to remedy the underlying cause of the edema. Eyedrops, injections of cortisone around the eye or laser surgery can be used to treat a macular edema. Recovery depends on the severity of the condition causing the edema.

The macula is the part of the retina responsible for acute central vision, the vision one uses for reading, watching television, and recognizing faces. A macular hole is a small round opening in the macula. The hole causes a blind spot or blurred area directly in the center of your vision. Most macular holes occur in the elderly. When the vitreous (the gel-like substance inside the eye) ages and shrinks, it can pull on the thin tissue of the macula, causing a tear that can eventually form a small hole. Sometimes injury or long-term swelling can cause a macular hole. No specific medical problem is known to cause macular holes. Vitrectomy surgery, the only treatment for a macular hole, removes the vitreous gel and scar tissue pulling on the macula and keeping the hole open. The eye is then filled with a special air bubble to push against the macula and close the hole. The air bubble will gradually dissolve, but the patient must maintain a face down position for one to two weeks to keep the gas bubble in contact with the macula. Success of the surgery often depends on how well the position is maintained. With treatment, most macular holes shrink and some of the lost central vision slowly returns. The amount of visual improvement typically depends on the length of time the hole was present. Some people with normal vision in the other eye may not want surgery, since vitrectomy surgery cannot completely restore vision.

Proliferative diabetic retinopathy is a complication of diabetes caused by changes in the blood vessels of the eye. If you have diabetes, your body does not use and store sugar properly. High blood sugar levels create changes in the veins, arteries and capillaries that carry blood throughout the body. This includes the tiny blood vessels in the retina, the light-sensitive nerve layer that lines the back of the eye.

In PDR, the retinal blood vessels are so damaged they close off. In response, the retina grows new, fragile blood vessels. Unfortunately, these new blood vessels are abnormal and grow on

the surface of the retina, so they do not resupply the retina with blood. Occasionally, these new blood vessels leak and cause a vitreous hemorrhage. Blood in the vitreous, the clear gel-like substance that fills the inside of the eye, blocks light rays from reaching the retina. A small amount of blood will cause dark floaters, while a large hemorrhage might block all vision, leaving only light and dark perception. The new blood vessels can also cause scar tissue to grow. The scar tissue shrinks, wrinkling and pulling on the retina and distorting vision. If the pulling is severe, the macula may detach from its normal position and cause vision loss. Laser surgery may be used to shrink the abnormal blood vessels and reduce the risk of bleeding. The body will usually absorb blood from a vitreous hemorrhage, but that can take days, months or even years. If the vitreous hemorrhage does not clear within a reasonable time, or if a retinal detachment is detected, an operation called a vitrectomy can be performed. During a vitrectomy, the eye surgeon removes the hemorrhage and the abnormal blood vessels that caused the bleeding. People with PDR sometimes have no symptoms until it is too late to treat them. The retina may be badly injured before there is any change in vision. There is considerable evidence to suggest that rigorous control of blood sugar decreases the chance of developing serious proliferative diabetic retinopathy. Because PDR often has no symptoms, if you have any form of diabetes you should have your eyes examined regularly by an ophthalmologist.

For Diabetic Patients: Information on diabetic glycemic indices and loads that includes regional and ethnic food including Indian: www.mendosa.com/gilists.htm

Retinitis pigmentosa (RP) describes a group of related diseases that tend to run in families and cause a slow but progressive loss of vision. RP affects the rods and cones of the retina, the light-sensitive nerve layer at the back of the eye, and results in a decline in vision in both eyes. RP usually affects both eyes equally with severity ranging from no visual problems in some families to blindness at birth in others. RP gets its name from the fact that one of the symptoms is a clumping of the retinal pigment that can be seen during an eye exam. The earliest symptom of retinitis pigmentosa, usually noticed in childhood, is night blindness or difficulty with night vision. People with normal vision adjust to the dark quickly, but people with night blindness adjust very slowly or not at all. A loss of side vision, or tunnel vision, is also common as RP progresses. Unfortunately, the combination of night blindness and the loss of peripheral vision can be severe and lead to legal blindness in many people. While there is a pattern of inheritance for RP, 40% of RP patients have no known previous family history. Learning more about RP in your family can help you and your ophthalmologist predict how RP will affect you. Usher's syndrome, in which a person is both deaf and blind, can be associated with RP. The incidence of Usher's syndrome is difficult to determine but surveys of patients suggest up to 10% of RP patients are deaf. The incidence of Usher's syndrome is three cases per 100,000. It is the most frequent cause of combined deaf-blindness in adults. Considerable research is being done to find the hereditary cause of RP. As hereditary defects are discovered it may be possible to develop treatments to prevent progression of the disease. While developments are on the horizon, particularly in the area of genetic research, there is currently no cure for retinitis pigmentosa. Nutritional supplements may have an effect on RP. It has been reported that Vitamin A can slow the progression of RP. Large doses of Vitamin A are harmful to the body and supplements of Vitamin E alone may make RP worse. Vitamin E is not harmful if taken with Vitamin A or in the presence of a normal diet. Your ophthalmologist can advise you about the risks and benefits of Vitamin A and how much you can safely take. Despite visual impairment, people with RP can maintain active and rewarding lives through the wide variety of rehabilitative services that are available today. Until there is a cure, periodic examinations by your ophthalmologist will keep you informed of legitimate scientific discoveries as they develop.