Diabetic Retinopathy

Diabetic retinopathy is a disease in which the retina is affected.

It can affect any patient with type 1 or type 2 diabetes. It is caused by damage to the vessels that supply the retina, the light-sensitive tissue at the back of the eye, with oxygen and nutrients.

Early symptoms are usually mild visual problems. If left untreated, diabetic retinopathy can lead to permanent loss of vision.

Most patients may not experience symptoms in the early stages of diabetic retinopathy. If symptoms are present, they tend to affect both eyes.

Symptoms that may occur when diabetic retinopathy progresses include:

• Spots or dark strings floating in the vision (floaters).
• Blurry vision
• Flactuating vision
• Impaired color perception
• Dark or empty areas in the vision.
• Permanent loss of vision

Diabetic retinopathy is caused by damage of the blood vessels that supply the retina of eye.

It can occur due to blockage of these blood vessels cutting off oxygen and nutrient supply to the retina. New blood vessels may develop due to this. However, these vessels don't develop properly and may become leaky.

There are two types of diabetic retinopathy:

Early diabetic retinopathy

Early diabetic retinopathy is also known as non-proliferative diabetic retinopathy (NPDR), in which there is no growth of new blood vessels.

The vessels of the retina gradually weaken and may have tiny bulges (microaneurysms) which protrude from the vessel wall, which may leak fluid into the eye and blood. Larger retinal vessels may become dilated. Nerve fibers in the retina may swell and this condition requires treatment.

Advanced diabetic retinopathy

Advanced diabetic retinopathy is also known as proliferative diabetic retinopathy, in which which blood vessels close off, causing the growth of new vessels in the retina.

These vessels may become leaky and this caused fluid to leak into the vitreous. Scar tissue stimulated the growth of new vessels can lead to retina detachment. New vessels may also interfere the normal flow of fluid from the eye leading to build up of pressure in the eye. This can further lead to damage of the optic nerve.

Diabetic retinopathy can be diagnosed by viewing the back of the eye. Doctors usually place a drop of a solution that dilates the pupils so that the retina can be seen easily. The drops can cause blurry vision which usually waters off after a few hours.

Doctors can check for :

• Abnormal blood vessels
• Swelling
• Growth of new blood vessels or scar tissue
• Bleeding in the vitreous
• Retinal detachment
• Abnormalities in the optic nerve

Doctors may also test vision, measure the pressure in the eye and look for evidence of cataracts.

A fluorescein angiography can be used to make pictures of the vessels of the eye to check for closed, broken down or leaking fluid.

Another test that can be used is optical coherence tomography, in which cross-sectional images of the retina are made. These images show the thickness of the retina and check if fluid has leaked into the retina. This test can also be used to check if treatment is working.

Treatment depends largely on the type of diabetic retinopathy that a patient has and how severe it is.

Early diabetic retinopathy

If a patient has mild or moderate non-proliferative diabetic retinopathy, he or she may not require treatment right away. However, close monitoring is required to determine when the patient might need treatment. When diabetic retinopathy is mild or moderate, good blood sugar control can usually slow the progression.

Advanced diabetic retinopathy 

If a patient has advanced proliferative diabetic retinopathy or macular edema, he or she may need prompt surgical treatment. 

Depending on the specific problems with the retina, options may include:

• Focal laser treatment: This laser treatment, also known as photocoagulation, can stop or slow the leakage of blood and fluid in the eye. During the procedure, leaks from abnormal blood vessels are treated with laser burns.

  If a patient has blurry vision from macular edema before surgery, the treatment might not return vision to normal, but it's likely to reduce the chance the macular edema may worsen.

• Scatter laser treatment: This laser treatment, also known as panretinal photocoagulation, can shrink the abnormal blood vessels. During the procedure, the areas of the retina away from the macula are treated with scattered laser burns. The burns cause the abnormal new blood vessels to shrink and scar. It's usually done in your doctor's office or eye clinic in two or more sessions.

  Patients may have be blurry vision for about a day after the procedure. Some loss of peripheral vision or night vision after the procedure is possible.

• Vitrectomy: This procedure uses a tiny incision in the eye to remove blood from the middle of the eye (vitreous) as well as scar tissue that's tugging on the retina. It's done in a surgery center or hospital using local or general anesthesia. Surgery often slows or stops the progression of diabetic retinopathy, but it's not a cure.

Because diabetes is a lifelong condition, future retinal damage and vision loss are still possible. Patients still require regular eye exams after surgery. At some point, additional treatment may be recommended.

Researchers are studying new treatments for diabetic retinopathy, including medications that may help prevent abnormal blood vessels from forming in the eye. Some of these medications are injected directly into the eye to treat swelling or abnormal blood vessels. These treatments appear promising, but more study is needed.

Taking regular eye tests, monitoring blood sugar and pressure, and early interventions for vision problems can help to prevent loss of vision from diabetic retinopathy.

The risk of developing diabetic retinopathy include:

• Eating a healthy diet and being physically active.
• Monitoring blood sugar level
• Controlling blood pressure and cholesterol.
• Quitting smoking
• Paying attention to vision changes.

Several alternative remedies exist for diabetic retinopathy, although they have not been scientifically proven.

Some of these treatments include herbs or supplements, which can interfere with other medication and can cause complications during surgery, such as excessive bleeding. Standard treatment should be continued if a patient wants to take alternative treatments.

There are different ways to adapt your lifestyle in coping with diabetic retinopathy.

Patients may require a therapist to help them deal with the fear of losing vision.

If a patient is experiencing some changes in vision, he or she can use magnifiers or services that can make daily living easier.

There are several risks and complications associated with diabetic retinopathy.

All patients with diabetes can develop diabetic retinopathy.

Risk factors include:

• Having diabetes for a long period of time.
• Poor control of blood sugar level
• High blood pressure and cholesterol.
• Pregnancy
• Tobacco use
• Being African-American, Hispanic or Native American.

Complications of diabetic retinopathy that can lead to serious problems with vision include:

• Vitreous hemorrhage - if bleeding occurs in the jelly-like substance that fills the center of the eye. Patients may see a few dark spots (floaters) and have their vision completely blocked in severe cases.
• Retinal detachment - in which the retina is pulled away from the back of the eye. Patients may see spots floating in the vision, flashes of light or severe vision loss.
• Glaucoma - a condition in which pressure builds up in the eye due to impaired flow of fluid from the eye.
• Complete blindness.