• Diabetic Retinopathy
• Epiretinal Membrane
• Macular Degeneration
• Macular Hole
• Proliferative Diabetic Retinopathy
• Retinal Detachment
• Retinal Tear
• Vitreous Detachment

What is Diabetic Retinopathy?
Diabetic retinopathy is the change that occurs in the blood vessels in the retina due to the abnormal blood sugar levels and other factors associated with diabetes mellitus. The retina is the light-sensitive tissue at the back of the eye that actually receives the light rays. Some of the small blood vessels, the capillaries, can become closed off. The retinal vessels can also leak fluid into the retina. Both the closure and the leakage can reduce vision.

How is Diabetic Retinopathy diagnosed?
Blurred vision is usually the first symptom of diabetic retinopathy. However, fairly advanced diabetic changes can occur with normal vision. This is why regular eye examinations are important for patients with diabetes. An ophthalmologist skilled at retinal exams can detect diabetic retinopathy. Usually, fluorescein angiography, a series of photographs taken after injection of a dye, can help to pinpoint areas of leakage and blood vessel closure.

How is Diabetic Retinopathy treated?
If there is significant leakage of fluid in the macula, the center of the retina responsible for fine, reading vision, laser treatment may be recommended. For this treatment, the patient places his chin in the chin rest of a microscope, and a contact lens is placed on the front surface of the eye, to focus the light rays at the back of the eye. There are bright flashes of light, but the treatment is not painful. Sometimes the vision is improved after laser treatment, but more commonly, the vision is stabilized. Studies have shown that diabetic complications, including eye problems, can be minimized by keeping the blood sugar and blood pressure as close to normal as possible.

What causes an epiretinal membrane?
An epiretinal membrane occurs in some eyes after the vitreous gel collapses and pulls away from the front surface of the retina, the light sensitive layer at the back of the eye. If the vitreous gel pulls off the outer layer of retinal cells, the resulting repair process can cause a membrane of scar tissue to form on the surface of the retina. Symptoms can include decreased vision and distortion.

What is the treatment for an epiretinal membrane?
There is no medical or laser treatment for epiretinal membrane. If the condition is severe enough, surgery to remove the vitreous gel, followed by removal of the membrane with delicate instruments can be considered. This is an outpatient surgery, done under local anesthesia.

How successful is the surgery?
In about 80% of the cases, distortion is decreased and vision improves by about 50%. If the patient's own lens is present, this operation will likely cause clouding of the lens, a cataract, which will require another operation. Of course, with any operation, severe, rare complications, such as infection or hemorrhage, can permanently decrease vision.

What is Macular Degeneration?
The macula is a small area of the retina located directly at the back of the eye. While the entire retina receives light rays, the macula is responsible for central vision, including fine detail and colors. When degenerative processes affect this region, the vision can be decreased. Sometimes abnormal new blood vessels grow through these thin degenerative areas, causing leakage of fluid, bleeding and scar tissue formation (wet AMD). Sometimes the retina simply becomes thinner and sees less well (dry AMD). Symptoms include decreased vision, blind spots in vision, and distortion (straight lines appearing curved or wavy). AMD is diagnosed by an examination, and by photography. The ophthalmologist examines the eye for signs of degeneration, leaking fluid, bleeding or scar tissue formation. A series of photographs, called a fluorescein angiogram, is taken to identify any leaking blood vessels. Other tests such as measuring the retinal thickness with OCT, can help to monitor AMD.

Is AMD treatable?
There is no cure for the degenerative aspect of AMD. However the Age Related Macular Degeneration Study has indicated that supplements with antioxidants may help prevent progression of dry AMD. Medicines to stop the abnormal blood vessels from leaking have been shown to be effective when injected to treat wet AMD. Standard laser and photodynamic therapy (PDT) are options that are less frequently used.

What should be done after the initial visit or treatment?
The goal is to save as much vision as possible. Sometimes, after treatment, the vision is improved, but usually we are happy to prevent further vision loss. Periodic visits are recommended, at least twice a year, and whenever a change is noted in the Amsler grid. If the vision is decreased in both eyes, low vision devices may be tried. Magnifying glasses, telescopes, and closed-circuit televisions are often the most useful. Although the vision loss with AMD can be frustrating, it is not expected that a total loss of vision will occur. Peripheral vision can be used even in most of the advanced cases.

How do I use the Amsler Grid?
The grid should be used with reading glasses, in good light and held at a comfortable reading distance. Both eyes are tested, one at a time. Covering one eye, the other eye is focused on the center dot, noting the location and size of any irregularities in vision - including wavy, fuzzy or gray areas, or blind spots. It is important to stay focused on the center dot and analyze the remainder of the grid using the peripheral vision. If changes occur and they persist for several days, the patient should be examined promptly.

What causes a macular hole?
The macula is the central portion of the retina, the light sensitive layer at the back of the eye. A hole occurs when the vitreous gel collapses away from the surface of the retina, exerting traction on its center. Symptoms include a decrease in vision and distortion.

How is the macular hole treated?
The macular hole can be treated with an outpatient operation performed with local anesthesia. A vitrectomy is performed, removing most of the vitreous gel from in front of the retina. A temporary bubble of gas is injected to flatten the macula and close the hole. Because the gas bubble rises to the highest part of the eye, and because it is necessary to press on the back part of the eye, the patient must keep his face down, 24 hours a day, for a week after surgery.

How successful is the operation?
The operation closes the macular hole 80 to 90% of the time, and vision is improved in most of the successful cases. If the patients own lens is present, this operation will likely cause clouding of the lens, a cataract, which will require another operation. Of course, with any operation, severe, rare complications, such as infection or hemorrhage, can permanently decrease vision.

What if nothing is done or the operation is not successful?
As time passes, the hole can increase in size, with some further decrease in vision. However, the vision typically stabilizes, and total blindness is not expected.

What is Proliferative Diabetic Retinopathy?
When diabetes has been present for several years, problems with the retina (the membrane in the back of the eye that acts like camera film) can develop. While the exact cause of diabetic retinopathy is not known, it appears that elevated blood sugar levels can cause damage to the blood vessels and red blood cells, reducing circulation to the retina. These problems can probably be minimized by good long-term control of blood sugar.

In proliferative diabetic retinopathy abnormal blood vessels develop on the retina. These vessels can lead to visual loss through bleeding or scar tissue formation.

The new abnormal blood vessels on the retina do not improve circulation; in fact, they are fragile and can bleed, causing vitreous hemorrhage, or bleeding, which can reduce vision. Sometimes the blood vessels release scar tissue, which can pull on the retina causing retinal detachment.

Abnormal blood vessels in proliferative diabetic retinopathy can be detected in a routine exam by the ophthalmologist. Sometimes additional tests such as fluorescein angiography are used.

What causes the bleeding and how is it treated?
Bleeding in proliferative diabetic retinopathy comes from the abnormal blood vessels; it usually is not the result of unusual activity by the patient. We therefore do not usually restrict activities in such patients. The main therapy for proliferative diabetic retinopathy is laser treatment, which is usually effective. If hemorrhage does occur, bed rest or head elevation may be prescribed to encourage the blood to settle. Injections of medicines can help speed the clearing of the blood. If the blood does not clear, vitrectomy, or surgical removal of the blood can be done.

What causes a Retinal Detachment?
The retina is the thin, light-sensitive layer of tissue that lines the inside back wall of the eye. When the vitreous gel pulls away from the front surface of the retina, a break in the retina is produced, if the vitreous is tightly attached to the retina. If fluid then goes through the hole, the retina pulls away from the wall of the eye, similar to wallpaper peeling off a wall, producing a retinal detachment. Because the retina receives a good portion of its nourishment from the wall of the eye, the vision decreases where the retina is detached. Typically this appears similar to a window shade being pulled across the vision.

How is the Retinal Detachment repaired?
The retina must be returned to its position against the wall of the eye, and the retinal break must be sealed to prevent fluid from going through the break again. The retinal break is sealed by either laser or cryotherapy (freezing treatment). There are a number of ways to accomplish this reattachment, depending on the type of retinal detachment present.

How successful is the treatment?
Approximately 95% of retinal detachments can be repaired, but it sometimes takes more than one proceedure to accomplish this. Usually there is good restoration of vision, but sometimes it is not as good as it was before the retinal detachment. As with any surgery, there can be rare unforeseen complications which can make matters worse, including severe bleeding, and serious infection. It should be kept in mind that retinal detachment is a serious condition, and can easily lead to blindness if nothing is done.

What causes a retinal tear?
A retinal tear occurs when the vitreous gel collapses and pulls away from the front surface of the retina. If the vitreous gel is more tightly attached to retina in one spot, the retina, the light sensitive layer at the back of the eye, can be torn. Symptoms can include new floaters and flashes of light

Is treatment for a retinal tear needed?
Usually treatment to seal a retinal tear is recommended to help prevent a retinal detachment. Laser treatment or freezing treatment, with or without injection of anesthetic around the eye is used. The location and type of retinal break determine the choice.

What symptoms can be expected after treatment of a retinal tear?
The laser or freezing treatment does not eliminate the flashes and floaters, which may be present for weeks or months in the future. If there are many new floaters or the sensation of a dark curtain coming across the vision is noted, a new tear or a retinal detachment might be present and the eye should be examined again.

What are the symptoms of vitreous detachment?
Sometimes this happens slowly and it is hardly noticed. Often there are flashes of light and the appearance of floaters in the vision. Whenever the retina is stimulated, it records this as light falling on. the retina-hence the flashes. The floaters represent condensations of protein that once were near the surface of the retina. With collapse of the vitreous gel, clumps of this protein are suspended in front of the retina, causing a shadow to be cast on the light sensitive retina by light entering the eye.

Is this dangerous? Is it related to retinal detachment?
Vitreous detachment in itself is not a threat to vision. Sometimes, however, if the vitreous is more strongly attached to the retina in one or more locations, the retina can be torn when the vitreous gel collapses. If a retinal tear occurs, fluid from the vitreous cavity can move through the tear, separating the retina from the other layers of the eye and causing a retinal detachment, a dangerous condition requiring surgery.

How do I know if I have a vitreous or a retinal detachment?
Both of the symptoms of vitreous detachment, flashes of light and floaters, may also be seen with retinal detachment. However, one other symptom of retinal detachment is never seen with vitreous detachment only. That is the sensation that a dark curtain or window shade is being pulled across the eye. If a dark area in vision or the appearance of new flashes or floaters are noticed, a prompt retinal examination is important.

What can be done about the irritating floaters?
While they can be a nuisance, no eye drops or medications can dissolve floaters and surgery is usually not indicated. With gravity they tend to sink down out of the line of sight, and may become less noticeable with time.