Diabetic eye disease refers to a group of eye problems that people with diabetes may face as a complication of diabetes. All can cause severe vision loss or even blindness.
Diabetic eye disease may include:
Diabetes is a disease that interferes with a person’s ability to metabolize sugar. In a person with diabetes, a prolonged period of high blood sugar can lead to the accumulation of fluid inside the lens of the eye, resulting in blurred vision. This blurring of vision will usually subside once the blood sugar levels are brought under control. Good control of blood sugar levels can also slow the onset and progression of diabetic retinopathy.
Diabetic retinopathy is a complication of diabetes that is caused by changes in the blood vessels of the eye. Over time, diabetes can affect the circulatory system of the retina. The retina is a nerve layer at the back of the eye that senses light and helps to send images to your brain.
When blood vessels in the retina are damaged, they may leak fluid or blood, and grow fragile, brush-like branches and scar tissue. This can blur or distort the images that the retina sends to the brain. The retina, the light-sensitive tissue at the back of the eye, must be healthy in order to provide good vision.
Diabetic retinopathy is the leading cause of new blindness among adults in the United States. People with untreated diabetes are said to be 25 times more at risk for blindness than the general population.
The longer a person has diabetes, the more the risk of developing diabetic retinopathy increases. About 80% of the people who have had diabetes for at least 15 years have some blood vessel damage to their retina. People with Type I or juvenile diabetes are more likely to develop diabetic retinopathy at a younger age.
If you have diabetes, it's 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.
There are often no visual symptoms in the early stages of diabetic retinopathy. You may never notice changes in your vision. That is why it is important for anyone with diabetes to have a comprehensive dilated eye exam at least once a year. Early detection and treatment can limit the potential for significant vision loss from diabetic retinopathy.
Blurred vision may occur, sometimes gradually, when the macula, the part of the retina that provides sharp, central vision, swells from leaking fluid. This is referred to as macular edema.
When bleeding occurs, your vision may become hazy, spotty or even disappear altogether. While there is no pain, proliferative retinopathy is a severe form of the disease and requires immediate medical attention.
There are two major stages of diabetic retinopathy. The first is non-proliferative diabetic retinopathy. In this stage the blood vessels of the retina become weak and tiny bulges known as microaneurysms begin to protrude from these blood vessels. These microaneurysms can leak fluid, causing swelling of the macula, also known as macular edema. The second, proliferative diabetic retinopathy is the more severe form of the disease. In this stage, as the blood supply to the retina becomes compromised, and the retina begins to become oxygen-deprived, the body sends signals for the retina to grow new blood vessels. These blood vessels have very thin, fragile walls, and can leak blood. This leaking of blood into the back of the eye can result in severe vision loss. Other complications of proliferative diabetic retinopathy can include retinal detachment and the development of glaucoma.
The best protection against diabetic retinopathy is to have regular medical eye examinations by your ophthalmologist. Serious retinopathy can be present without any symptoms. The disease can improve with treatment.
Diabetic retinopathy can be diagnosed through a comprehensive medical eye exam which includes a dilated exam of the eye. Eye drops are given to enlarge the pupils and allow your eye doctor to have a full view of the back of the eye, including the structures of the retina. If your ophthalmologist suspects diabetic retinopathy, he or she may order additional testing.
The goal of treatment for diabetic retinopathy is to slow or stop the progression of the disease. In the early stages, treatment may not be necessary, but you will need to continue having regular eye exams, and be closely monitored. It is also important to follow the advice of your physician in regards to your diet and exercise, and to keep your blood sugar levels well controlled.
Diabetic retinopathy is associated with the proliferation of a protein called vascular endothelial growth factor (VEGF) in the retina. VEGF stimulates the production of new blood vessels in the retina to try to bring more oxygen to the tissues because retinal blood circulation is inadequate due to diabetes.
These new blood vessels that form in the retina in response to VEGF are fragile. As they increase in number, they can cause fluid leakage, bleeding and scarring in the retina, resulting in vision loss.
Blood vessel leakage from diabetic retinopathy can cause fluid to accumulate in the macula, which is the most sensitive part of the retina that is responsible for central vision and color vision.
A group of drugs referred to as “Anti-VEGF medications” can be administered by injection into the middle cavity of the eye, where they bind to vascular endothelial growth factor (VEGF). This can help keep blood vessels in the eye from becoming leaky.
Research has shown that eye injections often result in better vision than laser treatment alone for patients with diabetic macular edema. The key to these treatments is their ability to block vascular endothelial growth factor (VEGF), the chemical signal that stimulates leakage and abnormal blood vessel growth.
If diabetic retinopathy progresses, the leakage of fluid from the blood vessels can lead to macular edema. Laser treatment is used to stop the leakage of blood and fluid into the retina. A powerful beam of laser light is focused on the damaged retina. Small bursts of the laser's beam seal leaking retinal vessels to reduce macular edema.
For abnormal blood vessel growth (neovascularization), the laser beam bursts are scattered throughout the side areas of the retina. The small laser scars reduce the abnormal blood vessel growth and help bond the retina to the back of the eye, preventing retinal detachment.
Laser surgery may be performed in your ophthalmologist's office or an outpatient clinic. If diabetic retinopathy is detected early, laser surgery slows down vision loss. Even in the more advanced stages of the disease, it reduces the chance of severe visual impairment.
If the vitreous is clouded by blood, laser surgery cannot be used until the blood settles or clears. In some cases of bleeding into the vitreous, cryotherapy, or freezing, of the retina, may help shrink the abnormal blood vessels.
In advanced proliferative diabetic retinopathy, the ophthalmologist may recommend a vitrectomy. This microsurgical procedure is performed in the operating room. A vitrectomy removes the blood-filled vitreous and replaces it with a clear solution.
About 70% of vitrectomy patients notice an improvement in sight after surgery. Sometimes the ophthalmologist may wait from several months up to a year to see if the blood clears on its own, before going ahead with a vitrectomy.
If scar tissue detaches the retina from the back of the eye, severe sight loss or blindness can result unless surgery is performed to reattach the retina.