If you have been diagnosed with Diabetes, you may be at risk of losing sight. Your body does not utilize sugar properly and, when the sugar levels rise, damage to the retinal blood vessels may occur. The injury to the retinal vessels is known as Diabetic Retinopathy. Diabetic Retinopathy is the leading cause of blindness in working age adults.

What are the manifestations of Diabetic Retinopathy?

Non proliferative retinopathy, or background diabetic retinopathy, is an early stage of diabetic retinopathy. In this stage, very small blood vessels in the retina leak blood or fluid. Many people with diabetes have non proliferative diabetic retinopathy yet retain excellent vision. When vision is affected it is the result of macular edema.

Macular edema is a swelling of the macula, the region of the retina that allows us to read fine print. The swelling is caused by an accumulation of fluid that has leaked from damaged retinal blood vessels. Vision loss may be mild to severe depending on the amount of leakage.

Proliferative diabetic retinopathy is present when abnormal new blood vessels begin growing on the optic nerve or on the surface of the retina. This occurs in response to poor circulation in the eye and the lack of oxygen delivered to the cells. These new blood vessels actually do not reestablish circulation in the retina and thus cause more harm than good. Proliferative diabetic retinopathy can cause visual loss in a few different ways.

Vitreous hemorrhage occurs when the fragile new blood vessels bleed into the cavity in the center of the eye that is normally filled with a clear, jelly-like substance. If the hemorrhage is small, one may see only a few dark floating spots. If the hemorrhage is larger, the entire vision may become cloudy. The hemorrhage may take days to months to reabsorb. If it does not clear up on its own, surgical evacuation by vitrectomy may be recommended. The visual prognosis is good if there is no damage to the macula.

Retinal detachment may occur when the new blood vessels shrink and form scar tissue that drags the retina away from its normal position. If the macula is involved, severe visual loss may occur.

Lastly, severe glaucoma may develop when the new blood vessels grow on the surface of the iris and block the normal flow of fluid leaving the eye. Pressure in the eye soars and causes damage to the optic nerve.

What are the symptoms of Diabetic Retinopathy?

Often, one may not be aware of any symptoms even when significant diabetic retinopathy is present. When macular edema occurs, vision often becomes blurry and may fluctuate.

If abnormal new blood vessels form, as in proliferative diabetic retinopathy, they may bleed and result in small specks or large floaters obscuring the vision. If a large hemorrhage occurs, vision often becomes blurry and may fluctuate.

How do we diagnose diabetic retinopathy?

A comprehensive eye examination by a general ophthalmologist or retina specialist is the only reliable means of detecting diabetic retinopathy. After the pupil is dilated, an intricate device called an ophthalmoscope is used to view the retina and determine the extent of the retinopathy. If diabetic retinopathy is discovered, a fluorescein dye test may be recommended. This involves injecting a vegetable based dye into the arm vein and taking photos of the retina as the dye passes through the circulation. This test is often necessary to determine which blood vessels are leaking fluid.

How do we treat diabetic retinopathy?

The best therapy is prevention. A nationwide study showed that strict control of blood sugar significantly lowered the risk of vision loss from diabetic retinopathy. Also, high blood pressure and kidney problems should be treated to minimize their effect on the retinopathy.

Laser surgery is often the first line of treatment if macular edema or proliferative retinopathy is present. For macular edema, the laser is focused on leaky areas of retina to aid in reabsorbing the excess fluid. The primary goal of treatment is to prevent further vision loss. It is uncommon for people to recover significant vision following treatment but some do experience partial restoration.

For proliferative diabetic retinopathy, the laser is focused on the retina outside the macula. This panretinal photocoagulation treatment causes the new blood vessels to involute and prevents further growth. It also decreases the risk of bleeding into the vitreous cavity.

Usually, multiple laser treatments over time are necessary to control the retinopathy. Laser surgery is not a cure for diabetic retinopathy and is not guaranteed to prevent further loss of vision.

In advanced cases of diabetic retinopathy vitrectomy, or the surgical removal of the vitreous gel and any scar tissue that exists, may be the only alternative to preserve or restore vision. This surgery is performed under a microscope in the operating room. Vitrectomy is indicated when bleeding in the vitreous does not reabsorb on its own or when a retinal detachment involves or threatens the macula.

Diabetic retinopathy is an important cause of blindness in our society. However, with modern examination techniques and cutting-edge treatments, visual loss is largely preventable. Stringent control of blood sugar levels and regular eye examinations by an ophthalmologist familiar with retinal diseases may reduce sharply the risk of blindness.