Eye Care Specialist SC
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  • Maintain optimum glucose levels
  • Lower blood pressure & cholesterol levels
  • Don't smoke
  • Check hemoglobin A1c levels frequently
  • Schedule annual dilated eye exams

What is Diabetic Retinopathy?

Diabetes is a condition which affects the body's ability to use and store sugar. Incidence of the disease is reaching epidemic proportions in our country—increasing six-fold in the last 30 years. Medical achievements have enabled those suffering from diabetes to better control their disease. However, as the lifespan of diabetics has increased, so has the incidence of related circulatory problems that can develop over time, including the sight-robbing complication known as diabetic retinopathy—a leading cause of blindness in Americans under age 65.

With diabetes, high blood sugar levels can weaken blood vessels in the eye, causing them to leak blood or fluid. This causes the retina to swell and form deposits that can lead to vision loss. Blood sugar fluctuations can also promote the growth of new, fragile blood vessels on the retina, which can sometimes leak blood into the vitreous (the clear, jelly-like substance that fills the eyeball). This retinal blood vessel damage, or “retinopathy,” can blur vision and lead to permanent impairment.

Of the more than 29 million Americans diagnosed with diabetes, it is estimated that up to 45 percent have some degree of retinopathy. Diabetic retinopathy is the leading cause of blindness among working-age Americans.

Risk Factors for Diabetic Retinopathy

All diabetics (Type I or II, insulin-dependent or not) are at risk for developing retinopathy. Diabetes also doubles the risk for developing cataracts and glaucoma. The following factors can affect the incidence and degree of diabetic eye disease:

Types of Diabetic Retinopathy

Background Diabetic Retinopathy

Background diabetic retinopathy Background diabetic retinopathy results from leakage of the small retinal blood vessels. These capillaries may either become occluded (blocked) or dilated (swollen), leading to the development of microaneurysms (tiny swollen sacs in the vessels). Diabetic blood vessels and microaneurysms often leak fluid, blood and fatty materials into the retina. This leakage can make the retina wet, swollen, and unable to function properly.

When swelling occurs in the central part of the retina (the macula), it is known as "macular edema." The macula is the small, highly specialized center of the retina that is responsible for "straight-ahead" vision. Macular edema usually affects both eyes, but not necessarily to the same degree. Typically, there is no pain or redness, and any blurriness or distortion of vision is of varying extent. Only when deposits or fluid involve the macular area is a decrease in vison actually noticed. Because of this, some patients with significant background diabetic retinopathy may still have excellent vision if the macula is spared.

Background diabetic retinopathy is the most common form of the disease, accounting for 80 to 90 percent of all cases. Although it rarely leads to total blindness, 5 to 20 percent of patients with the condition may become legally blind (20/200 or less vision) within five years.

Proliferative Diabetic Retinopathy

Proliferative diabetic retinopathy Proliferative diabetic retinopathy is the most severe vision-related complication of diabetes, often leading to blindness if left untreated. It develops in 10 to 15 percent of diabetics.

Proliferative diabetic retinopathy begins in the same manner as background retinopathy but is then marked by the growth ("proliferation") of new blood vessels ("neovascularization") on the surface of the retina or optic nerve head. To further explain, with proliferative retinopathy, the retina is unable to obtain valuable nutrients needed for the vision process. To compensate, new blood vessels grow. Unfortunately, however, these vessels are very fragile and may end up further damaging the eye by causing other problems that can lead to permanent loss of vision and even loss of the eye, including:

Vitreous Hemorrhage:  With this, the fragile new vessels rupture and bleed into the vitreous (the clear, jelly-like fluid that fills the center of the eye). Symptoms to watch for include fairly sudden loss or blurring of vision and seeing numerous floating spots (resembling spider webs) or a dense veil or dark spots.

Retinal Detachment:  Although vitreous bleeding usually clears with time, it can (especially with repeated hemorrhages) create scar tissue. This scar tissue may tighten and pull on the retina, causing it to detach from the back of the eye. Symptoms include sudden onset of floaters or a cobweb or curtain effect. Retinal detachment may result in severe vision loss or even blindness.

Rubeosis:  Growth of abnormal new blood vessels on the iris (the colored part of the eye), rather than the retina, that can lead to the following problem.

Neovascular Glaucoma:  Rubeosis vessels on the iris can block the natural flow of fluid out of the eye. This increases pressure in the eye, leading to a severe form of glaucoma ("neovascular") that can result in permanent vision loss.

Proliferative diabetic retinopathy can occur in adult-onset diabetics, but it is more likely to develop in juvenile-onset diabetics, affecting almost 60 percent of those patients with more than 30 years of insulin-dependence. Over a five-year period, 50 percent of patients with the condition will become legally blind if they do not have treatment. Thus, it is especially important to detect this more severe form of diabetic retinopathy early.

Diabetic Retinopathy Symptoms

Background Diabetic Retinopathy

Typically, there is no pain or redness, and symptoms include blurred or distorted vision of varying extent. Only when deposits or fluid involve the macular area is decreased vision actually noted. Thus, some patients with significant background diabetic retinopathy may still have excellent vision if the macula is spared.

Proliferative Diabetic Retinopathy

For most people with proliferative retinopathy, there are no early symptoms. There is no pain, blurriness or inflammation. Patients may have good (or near normal) vision until the onset of vitreous hemorrhage or another serious problem causes symptoms. Others may, however, notice a change in their central and/or color vision as a result of macular edema (the leaking of blood vessels onto the central retina, or macula). This can often be treated if detected early.

Because of the lack of and/or variation in symptoms, it is vital for ALL diabetics to schedule regular comprehensive eye exams.

Diabetic Retinopathy Detection, Diagnosis and Monitoring

Diabetic eye disease is detected through comprehensive eye examinations involving dilation of the pupil (enlarging with drops) to best see into the back of the eye. The following methods may be used to diagnose and monitor diabetic retinopathy.

Ophthalmoscopy:  An instrument called an ophthalmoscope is used to check for early signs of retinopathy, such as microaneurysms (tiny blister-like outcroppings on retinal blood vessels that can bulge and leak), before noticeable vision loss occurs.

Ultrasonic Testing:  In cases where bleeding obscures viewing of the retina, ultrasonic testing can be useful to ensure that bleeding and scar tissue has not caused a retinal detachment.

Optical Coherence Tomography (OCT):  Eye Care Specialists is pleased to join such prestigious centers across the country as Johns Hopkins and Bascom Palmer Eye Institute in offering the newest advancement in diabetic retinopathy diagnosis and tracking—Optical Coherence Tomography (OCT). Similar to a CT scan, the OCT creates detailed computer printouts that provide unparalleled accuracy in visualizing and measuring the severity and extent of swelling (“macular edema”) present from diabetic retinopathy.

During the fast, painless OCT procedure, patients simply focus on a light while a safe, invisible laser scans the back of the eye to acquire an image in just seconds. This “optical ultrasound” of the anatomic layers of the retina and optic nerve enables us to detect and track not only signs of diabetic retinopathy, but also glaucoma, macular degeneration, and other sight-threatening diseases—often before any damage occurs. (This is especially important for diabetics, since they are at a much greater risk for developing glaucoma and other vision problems.) Follow-up OCT scans are then used to promptly detect and treat any abnormalities with the necessary medications, laser therapy or surgery—thus helping to prevent any future loss of vision.

Fluorescein Angiography:  This procedure is sometimes required in special cases requiring further testing. A fluorescein dye is injected into the patient's arm vein. After the dye circulates throughout the body to the blood vessels inside the eye, a special camera takes a rapid series of pictures. (The retina is the only part of the body where blood vessels can be seen directly.) Normal retinal vessels won't leak the dye. Abnormal small diabetic retinal vessels and neovascular (new) vessels, however, may leak the dye and can be captured on film. As a result, fluorescein angiography can aid in the diagnosis and classification of diabetic retinopathy. It can also be used as a "roadmap" when laser treatment of leaky blood vessels is indicated.

In addition to undergoing examination and testing, it is important that you provide your doctor with an accurate medical history, including any vision symptoms or concerns, hereditary problems, and medication use.

Should You Be Screened for Diabetic Eye Disease?

Do you have diabetes? Was your last eye exam more than a year ago?

If you can answer “Yes” to those two questions, then it’s time to have your vision checked. It is vital to understand that significant retinopathy may be present before noticeable vision loss occurs (if the macula is spared). As such, early detection and treatment are crucial to reducing the risk of vision loss from diabetes. Therefore, all diabetics should:

  1. Schedule yearly comprehensive dilated eye exams (more often, if recommended).
  2. Call your eye care specialist immediately if you notice floating spots (like spider webs), a "veil" over your vision, or other changes (not associated with blood sugar fluctuations).
  3. Schedule an eye exam if you become pregnant, since this can speed the progression of retinopathy.
  4. And, remember, whether you are diabetic or not, after age 40, EVERYONE should have their eyes checked at least every two years for other conditions, like glaucoma, that may be causing permanent vision loss without you even noticing it.

    (NOTE: Eye appointments are often covered by insurance, Medicare or Medicaid; and payment and financing options are also often available.)

Methods of Controlling Diabetic Retinopathy

Although diabetic retinopathy can NOT be prevented or cured, prompt diagnosis, diligent monitoring and timely treatment can control the sight-robbing effects of diabetes. The following steps are used to protect vision.

Medical and Lifestyle

Blood Sugar Control
Besides being important for your general health, good long-term control of diabetes through medication, diet and exercise may also greatly reduce your risk of vision loss. Studies have shown:

  1. In diabetics with no eye disease, excellent blood sugar control reduced the risk of developing retinopathy by 76%.
  2. In patients with mild retinopathy, excellent blood sugar control slowed its progression by 54% and reduced the development of severe diabetic retinopathy by 47%.

Healthy Lifestyle
Proper diet and exercise are crucial to anyone's good health, especially people with diabetes. Also, controlling blood pressure and not smoking definitely decrease the complications of diabetes, including retinopathy.

Regular Check-Ups
See your doctor, endocrinologist and eye care specialist as often as recommended. Surprisingly, a study found that one-third of people who know they have diabetes do not adhere to guidelines for yearly dilated eye exams. Why do you need your eyes checked, especially if your blood sugar has always been under control? Regular eye exams are important because diabetes is also a disease of the tiny blood vessels, especially the capillaries, and retinopathy may progress independent of blood sugar levels. Duration of the disease (number of years having diabetes) is really the most critical factor in determining the development and extent of retinopathy and whether you need treatment.

Deciding when or whether to use injection, laser or surgical treatment depends on careful evaluation of the type, location and severity of your retinopathy and your doctor’s opinion as to how well the condition may (or does) respond to treatment.

Injection Treatment

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Our practice has been very pleased with the success of new medications (Avastin, Eylea and Lucentis) that can be painlessly injected directly into the eye to decrease both blood vessel leakage and abnormal new growth—thus staving off progression of diabetic eye disease. Our patients have experienced excellent results with injections, including not only stabilization of vision, but in some cases, measurable improvement in sight. Studies in 2011 established the primary role of medication injection in the treatment of diabetic macular edema. Protocols exist for the use and frequency of injections (typically every 4-12 weeks). Medication injections may also be used in conjunction with laser treatment, as described next.

Laser Treatment

Diabetic retinopathy laser treatment Although not all diabetics can have or need laser treatment, it has proven very effective in reducing severe vision loss, especially if begun early enough. Its main goal, however, is to stabilize retinopathy—not to restore lost vision. Treatment is performed in our office or outpatient surgery center using topical (drops) or local (injection) anesthesia.

During laser photocoagulation, a high-energy beam of light is focused onto specific areas of the retina. This light turns to heat and seals leaking blood vessels (for background retinopathy) or helps prevent the growth of abnormal new vessels (for proliferative retinopathy).

Laser Treatment for Background Diabetic Retinopathy
The immediate goal of laser photocoagulation in background diabetic retinopathy is to seal individual leaking vessels, thus hopefully halting further vision loss. However, since the laser only seals current leaks, it is common to require repeat treatment as other vessels begin to leak. There are two types of laser treatment used for background diabetic retinopathy: "focal" and "grid." With focal treatment, the laser targets specific areas of leakage pinpointed by fluorescein angiography testing. In some patients, however, the leakage into the retina is widespread and diffuse, rather than from a few specific leaking blood vessels. For these cases, the laser is used to make a grid pattern across the entire leaking ("wet") area. Patients can sometimes see the small spots where focal or grid treatment was done, but this rarely poses a problem. A study of laser treatment for background retinopathy showed that early use for macular edema (fluid in the macula) decreased the incidence of marked vision loss by 50 percent. In some cases, however, leakage is already so far advanced that promising results are much less likely. As such, patients need to realize that laser therapy is not always successful and that preservation of current vision, not improvement, is the primary goal.

Laser Treatment for Proliferative Diabetic Retinopathy
With proliferative diabetic retinopathy, laser photocoagulation aims to prevent further new vessel development and to shrink existing vessels (or, ideally, make them disappear completely). This then decreases the chance of hemorrhaging and subsequent loss of vision. Proliferative treatment is commonly done over a period of two to four sessions per eye and involves placing 1,000 to 3,000 separate tiny laser burns in the outer area (periphery) of the retina. Studies have long proven the usefulness of this therapy, showing about a 60 percent reduced incidence of severe vision loss with appropriate and timely treatment. There is no guarantee for success, however, especially if laser therapy is not started until late in the course of retinopathy.

The most common side effects of laser therapy include an occasional slight decrease in central and/or night vision, and a restriction in peripheral (side) vision. However, these are rarely a major problem and are a small price to pay for the significantly increased chance of retaining vision through laser treatment.

Surgical Treatment

If laser photocoagulation is impossible or unsuccessful in preventing recurrent vitreous hemorrhage, scar formation or retinal detachment, an operation known as a vitrectomy may be performed. This is a major surgical procedure in which the bloody fluid and abnormal scar tissue in the vitreous cavity are removed and replaced with a clear, artificial solution. Although complications may occur, about two-thirds of patients have some vision improvement with this technique.

Steps to Reduce Diabetes-Related Vision Loss

What the Future Holds

Scientists are focusing on the changes that cause vessels to leak and proliferate in diabetic retinopathy and are having success in blocking these disease processes. Such research aims to produce treatments that could prevent blood vessel leakage or fragile new growth (neovascularization) from ever occurring and do a better job of reversing retinopathy if it does occur. Furthermore, new instruments and techniques are being studied and introduced to improve the success rate of surgery for vitreous hemorrhage and diabetic retinal detachment.

Blindness due to diabetes places physical, emotional and financial tolls on patients, their loved ones and society. Although, at present, we cannot prevent or cure diabetic retinopathy, early detection, careful tracking, and timely treatment can often decrease the risk of severe visual loss. Those are steps worth taking to gain every opportunity to see life to the fullest—now . . . and in the future.

For more information or a comprehensive examination . . .

Since 1985, Eye Care Specialists has provided comprehensive medical, surgical and laser care for virtually every eye condition to more than 130,000 people in southeastern Wisconsin. If you would like detailed booklets/handouts on the information contained in this section or other eye-related topics, please contact our Communications & Education Department at 414-321-7035. To schedule a comprehensive eye evaluation, call one of our three convenient Milwaukee-area locations directly.