WHAT ARE FLOATERS?

You may sometimes see small specks or clouds moving in your field of vision. These are called floaters. You can often see them when looking at a plain background, like a blank wall or blue sky. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear gel-like fluid that fills the inside of your eye. While these objects look like they are in front of your eye, they are actually floating inside it. What you see are the shadows they cast on the retina, the layer of cells lining the back of the eye that senses light and allows you to see. Floaters can appear as different shapes such as little dots, circles, lines, clouds, or cobwebs.

WHAT CAUSES FLOATERS?

When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. This is a common cause of floaters.

Posterior vitreous detachment is more common in people who:

• Are nearsighted

• Have undergone cataract operations

• Have had YAG laser surgery of the eye

• Have had inflammation inside the eye

The appearance of floaters may be alarming, especially if they develop very suddenly. You should contact your ophthalmologist (Eye M.D.) right away if you develop new floaters, especially if you are over 45 years of age.

ARE FLOATERS EVER SERIOUS?

The retina can tear if the shrinking vitreous gel pulls away from the wall of the eye. This sometimes causes a small amount of bleeding in the eye that may appear as new floaters. A torn retina is always a serious problem, since it can lead to a retinal detachment.

You should see your ophthalmologist at Lakeland Eye Clinic As soon as possible if:

• Even one new floater appears suddenly

• You see sudden flashes of light

If you notice other symptoms, like the loss of side vision, you should see your ophthalmologist.

CAN FLOATERS BE REMOVED?

Floaters may be a symptom of a tear in the retina, which is a serious problem. If a retinal tear is not treated, the retina may detach from the back of the eye. The only treatment for a detached retina is surgery. Other floaters are harmless and fade over time or become less bothersome, requiring no treatment. Even if you have had floaters for years, you should schedule an eye examination with your ophthalmologist if you suddenly notice new ones.

WHAT CAUSES FLASHING LIGHTS?

When the vitreous gel rubs or pulls on the retina, you may see what look like flashing lights or lightning streaks. You may have experienced this same sensation if you have ever been hit in the eye and seen “stars.”

The flashes of light can appear off and on for several weeks or months. As we grow older, it is more common to experience flashes. If you notice the sudden appearance of light flashes, you should contact your ophthalmologist immediately in case the retina has been torn.

Floaters and flashes of light become more common as we grow older. While not all floaters and flashes are serious, you should always have a medical eye examination by an ophthalmologist to make sure there has been no damage to your retina.

DIABETES CAN AFFECT SIGHT

If you have diabetes mellitus, your body does not use and store sugar properly. High blood-sugar levels can damage blood vessels in the retina, the nerve layer at the back of the eye that senses light and helps to send images to the brain. The damage to retinal vessels is referred to as diabetic retinopathy.

TYPES OF DIABETIC RETINOPATHY

Nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR). NPDR, commonly known as background retinopathy, is an early stage of diabetic retinopathy. In this stage, tiny blood vessels within the retina leak blood or fluid. The leaking fluid causes the retina to swell or to form deposits called exudates.

Many people with diabetes have mild NPDR, which usually does not affect their vision. When vision is affected it is the result of macular edema (pronounced eh-DEEM-uh) and/or macular ischemia (pronounced ih-SKEE-mee-uh).

Macular edema is swelling or thickening of the macula, a small area in the center of the retina that allows us to see fine details clearly. The swelling is caused by fluid leaking from retinal blood vessels. It is the most common cause of visual loss in diabetes. Vision loss may be mild to severe, but even in the worst cases, peripheral vision continues to function. Macular ischemia occurs when small blood vessels (capillaries) close. Vision blurs because the macula no longer receives sufficient blood supply to work properly.

PDR is present when abnormal new vessels (neovascularization) begin growing on the surface of the retina or optic nerve. The main cause of PDR is widespread closure of retinal blood vessels, preventing adequate blood flow. The retina responds by growing new blood vessels in an attempt to supply blood to the area where the original vessels closed. Unfortunately, the new abnormal blood vessels do not resupply the retina with normal blood flow. The new vessels are often accompanied by scar tissue that may cause wrinkling or detachment of the retina. PDR may cause more severe vision loss than NPDR because it can affect both central and peripheral vision.

Proliferative diabetic retinopathy causes visual loss in the following ways:

Vitreous hemorrhage: The fragile new vessels may bleed into the vitreous, a clear, gel-like substance that fills the center of the eye. If the vitreous hemorrhage is small, a person might see only a few new, dark floaters. A very large hemorrhage might block out all vision. It may take days, months, or even years to reabsorb the blood, depending on the amount of blood present. If the eye does not clear the vitreous blood adequately within a reasonable time, vitrectomy surgery may be recommended. Vitreous hemorrhage alone does not cause permanent vision loss. When the blood clears, vision may return to its former level unless the macula is damaged.

TRACTION RETINAL DETACHMENT:

When PDR is present, scar tissue associated with neovascularization can shrink, wrinkling and pulling the retina from its normal position. Macular wrinkling can cause visual distortion. More severe vision loss can occur if the macula or large areas of the retina are detached.

Neovascular glaucoma: Occasionally, extensive retinal vessel closure will cause new, abnormal blood vessels to grow on the iris (colored part of the eye) and block the normal flow of fluid out of the eye. Pressure in the eye builds up, resulting in neovascular glaucoma, a severe eye disease that causes damage to the optic nerve.

HOW IS DIABETIC RETINOPATHY DIAGNOSED?

A medical eye examination is the only way to detect changes inside your eye. An ophthalmologist (Eye M.D.) can often diagnose and treat serious retinopathy before you are aware of any vision problems. The ophthalmologist dilates your pupil and looks inside of the eye with an ophthalmoscope. If your ophthalmologist finds diabetic retinopathy, he or she may order color photographs of the retina or a special test called fluorescein angiography to find out if you need treatment. In this test a dye is injected into your arm and photos of your eye are taken to detect where fluid is leaking.

HOW IS DIABETIC RETINOPATHY TREATED?

The best treatment is to prevent the development of retinopathy as much as possible. Strict control of your blood sugar will significantly reduce the long-term risk of vision loss from diabetic retinopathy. If high blood pressure and kidney problems are present, they need to be treated.

Laser surgery: Laser surgery is often recommended for people with macular edema, PDR, and neovascular glaucoma. For macular edema, the laser is focused on the damaged retina near the macula to decrease the fluid leakage. The main goal of treatment is to prevent further loss of vision. It is uncommon for people who have blurred vision from macular edema to recover normal vision, although some may experience partial improvement. A few people may see the laser spots near the center of their vision following treatment. The spots usually fade with time but may not disappear. For PDR, the laser is focused on all parts of the retina except the macula. This panretinal photocoagulation treatment causes abnormal new vessels to shrink and often prevents them from growing in the future. It also decreases the chance that vitreous bleeding or retinal distortion will occur. Multiple laser treatments over time are sometimes necessary. Laser surgery does not cure diabetic retinopathy and does not always prevent further loss of vision.

Vitrectomy: In advanced PDR, your ophthalmologist may recommend a vitrectomy. During this microsurgical procedure, which is performed in the operating room, the blood-filled vitreous is removed and replaced with a clear solution. Your ophthalmologist may wait for several months or up to a year to see if the blood clears on its own before performing a vitrectomy. Vitrectomy often prevents further bleeding by removing the abnormal vessels that caused the bleeding. If the retina is detached, it can be repaired during the vitrectomy surgery. Surgery should usually be done early because macular distortion or traction retinal detachment will cause permanent visual loss. The longer the macula is distorted or out of place, the more serious the vision loss will be.

VISION LOSS IS LARGELY PREVENTABLE

If you have diabetes, it is important to know that today, with improved methods of diagnosis and treatment, only a small percentage of people who develop retinopathy have serious vision problems. Early detection of diabetic retinopathy is the best protection against loss of vision. You can significantly lower your risk of vision loss by maintaining strict control of your blood sugar and visiting your ophthalmologist regularly.

WHEN TO SCHEDULE AN EXAMINATION

People with diabetes should schedule examinations at least once a year. More frequent medical eye examinations may be necessary after a diagnosis of diabetic retinopathy. Pregnant women with diabetes should schedule an appointment in the first trimester, because retinopathy can progress quickly during pregnancy.

If you need to be examined for eyeglasses, it is important that your blood sugar be consistently under control for several days when you see your ophthalmologist. Eyeglasses that work well when blood sugar is out of control will not work well when blood sugar is stable.

Rapid changes in blood sugar can cause fluctuating vision in both eyes even if retinopathy is not present. You should have your eyes checked promptly if you have visual changes that:

• Affect only one eye

• Last more than a few days

• Are not associated with a change in blood sugar

When you are first diagnosed with diabetes, you should have your eyes checked:

• Within five years of the diagnosis if you are 29 years old or younger

• Within a few months of the diagnosis if you are 30 years old and older

A RETINAL VEIN OCCLUSION OCCURS WHEN A VEIN IN THE EYE’S RETINA IS BLOCKED

The retina is the layer of light-sensing cells lining the back of your eye. It converts light rays into signals, which are sent through the optic nerve to your brain where they are recognized as images. A blocked vein damages the blood vessels of the retina. Hemorrhages (bleeding) and leakage of fluid occurs from the areas of blocked blood vessels.

There are two different types of retinal vein occlusion:

• Central retinal vein occlusion (CRVO): when the main vein of the eye (located at the optic nerve) becomes blocked

• Branch retinal vein occlusion (BRVO): when one of the smaller branches of vessels attached to the main vein becomes blocked

WHO IS AT RISK FOR A RETINAL VEIN OCCLUSION?

Certain illnesses increase your risk for developing retinal vein occlusion, including:

• Diabetes

• Glaucoma

• High blood pressure

• Age-related vascular (blood vessel) disease

• Blood disorders

If a branch retinal vein occlusion occurs in one eye, there is an increased chance (about 10%) that a branch or central vein occlusion will occur in the other eye in the future.

WHAT ARE THE COMPLICATIONS AND SYMPTOMS OF RETINAL VEIN OCCLUSION?

Macular edema: If blood and fluid leak into the central part of the retina called the macula, swelling of the macula occurs (called macular edema). The macula is the part of your retina responsible for your fine detail vision. It is what allows you to read small print, thread a needle, and read street signs. Macular edema causes blurred and/or decreased vision.

Abnormal blood vessel growth (neovascularization): Retinal vein occlusion can cause abnormal vessels to begin to grow in the retina. These new vessels are very fragile and may bleed or leak fluid into the vitreous—the gel-like substance that fills the center of the eye. Small spots or clouds in your field of vision called floaters can appear. In more advanced cases of neovascularization, the abnormal blood vessels may actually cause the retina to detach from the back of the eye.

Pain in the eye: In severe cases of CRVO, a blocked vein causes abnormal blood vessel growth, leading to painful pressure in the eye (rubeosis). If complications from retinal vein occlusion are not treated, irreversible blindness may occur.

HOW IS RETINAL VEIN OCCLUSION DETECTED?

Your ophthalmologist detects retinal vein occlusion by examining the retina with an instrument called an ophthalmoscope. He or she may also perform fluorescein angiography, a procedure that takes special photographs of the eye, in order to further investigate the blood vessels in your eye.

HOW IS RETINAL VEIN OCCLUSION TREATED?

There is no known cure for retinal vein occlusion, though in some cases laser surgery may be used to reduce the macular edema and stabilize or improve vision. In severe CRVO, laser surgery is used to prevent or treat the abnormal blood vessel growth that can lead to glaucoma.

You may be able to prevent retinal vein occlusion from occurring again by properly managing any health conditions that contribute to this eye problem (such as diabetes, glaucoma or high blood pressure.

WHAT IS THE RETINA?

The retina is a nerve layer at the back of your eye that senses light and sends images to your brain. An eye is like a camera. The lens in the front of the eye focuses light onto the retina. You can think of the retina as the film that lines the back of a camera.

WHAT IS A RETINAL DETACHMENT?

A retinal detachment occurs when the retina is pulled away from its normal position. The retina does not work when it is detached. Vision is blurred, just as a photographic image would be blurry if the film were loose inside the camera. A retinal detachment is a very serious problem that almost always causes blindness unless it is treated.

WHAT CAUSES RETINAL DETACHMENT?

A clear gel called vitreous (vit-ree-us) fills the middle of the eye. As we get older, the vitreous may pull away from its attachment to the retina at the back of the eye. Usually the vitreous separates from the retina without causing problems. But sometimes the vitreous pulls hard enough to tear the retina in one or more places. Fluid may pass through the retinal tear, lifting the retina off the back of the eye, much as wallpaper can peel off a wall.

The following conditions increase the chance of having a retinal detachment:

• Nearsightedness

• Previous cataract surgery

• Glaucoma

• Severe injury

• Previous retinal detachment in your other eye

• Family history of retinal detachment

• Weak areas in your retina that can be seen by your ophthalmologist

WHAT ARE THE WARNING SYMPTOMS OF RETINAL DETACHMENT?

These early symptoms may indicate the presence of a retinal detachment:

• Flashing lights

• New floaters

• A shadow in the periphery of your field of vision

• A gray curtain moving across your field of vision

These symptoms do not always mean a retinal detachment is present; however, you should see your ophthalmologist as soon as possible. Your ophthalmologist can diagnose retinal detachment during an eye examination in which he or she dilates (enlarges) the pupils of your eyes. Some retinal detachments are found during a routine eye examination. Only after careful examination can your ophthalmologist tell whether a retinal tear or early retinal detachment is present.

RETINAL TEARS

Most retinal tears need to be treated with laser surgery or cryotherapy (freezing), which seals the retina to the back wall of the eye. These treatments cause little or no discomfort and may be performed in your ophthalmologist’s office. Treatment usually prevents retinal detachment.

RETINAL DETACHMENTS

Almost all patients with retinal detachments require surgery to return the retina to its proper position.

 TYPES OF SURGERY

There are several ways to fix a retinal detachment. The decision about which type of surgery and anesthesia (local or general) 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.

WHAT ARE THE RISKS OF SURGERY?

Any surgery has risks; however, an untreated retinal detachment usually results in permanent severe vision loss or blindness. Some of the surgical risks include:

• Infection

• Bleeding

• High pressure in the eye

• Cataract

Most retinal detachment surgery is successful, although a second operation is sometimes needed. If the retina cannot be reattached, the eye will continue to lose sight and ultimately become blind. The more severe the detachment, the less vision may return.

WHAT IS UVEITIS?

In most cases of uveitis, the cause of the disease remains unknown. Uveitis has many different causes:

• A virus, such as shingles, mumps, or herpes simplex

• A fungus, such as histoplasmosis

• A parasite, such as toxoplasmosis

• Related disease in other parts of the body, such as arthritis, gastrointestinal disease, or collagen vascular disease such as lupus

• A result of injury to the eye

HOW IS UVEITIS DIAGNOSED?

A careful eye examination by an ophthalmologist is extremely important when symptoms occur. Inflammation inside the eye can permanently affect sight or even lead to blindness if it is not treated. Your ophthalmologist will examine the inside of your eye. He or she may order blood tests, skin tests, or x-rays to help make the diagnosis.

HOW IS UVEITIS TREATED?

Uveitis is a serious eye condition that may scar the eye. It needs to be treated as soon as possible. Eyedrops, especially corticosteroids and pupil dilators, can reduce inflammation and pain. For more severe inflammation, oral medication or injections may be necessary.

Uveitis can be associated with these complications:

• Glaucoma (increased pressure in the eye)

• Cataract (clouding of the eye’s natural lens)

• Neovascularization (growth of new, abnormal blood vessels)

• Damage to the retina, including retinal detachment

These complications also may need treatment with eyedrops, conventional surgery, or laser surgery. If you have a “red eye” that does not clear up quickly, contact your ophthalmologist. Since uveitis can be associated with disease in other parts of the body, your ophthalmologist will want to know about your overall health. He or she may want to consult with your primary care physician or other medical specialists.