Diabetic retinopathy is a disorder of the retinal blood vessels resulting from diabetes mellitus. Diabetic retinopathy is the leading cause of new blindness in working adults in developed countries. The trend is also becoming similar in Singapore. The incidence of diabetic retinopathy increases with the duration of diabetes. About 60% of patients having diabetes for 15 years or more will have some blood vessel damage in their eyes and a percentage of these are at risk of developing blindness.

Forms Of Diabetic Retinopathy

Background Retinopathy

Background retinopathy is an early stage of diabetic retinopathy and progresses slowly over the years. The retina usually shows evidence of tiny blood spots or fatty deposits.

The majority of patients do not develop vision loss except for a gradual blurring of vision which can often go unnoticed. In some patients, blood vessels leak at the macula Ð the part of the retina responsible for central vision, causing loss of vision.

A special photographic process is very helpful in detecting early effects of diabetic retinopathy. This is known as fundus flourescein angiography (FFA) and will sometimes be recommended by your ophthalmologist. The procedure involves injection of a dye through the arm into the blood stream. As the dye is carried to the eye, photographs of the retina are taken, showing areas of leakage or poor blood flow.

Proliferative Retinopathy

Proliferative retinopathy develops from background retinopathy and is responsible for most of the visual loss in diabetes. New blood vessels grow (proliferate) on the surface of the retina and optic nerve. These immature blood vessels tend to rupture and bleed into the vitreous cavity. Scar tissues can also grow from ruptured blood vessels which will contract and pull on the retina, detaching it with the resulting loss of vision. New vessels can also grow on the iris and cause a form of glaucoma, which itself can lead to blindness.

When bleeding occurs in proliferative retinopathy, the patient has hazy or complete loss of sight. Though there is no symptom of pain, this severe form of diabetic retinopathy requires immediate medical attention.

Treatment

Control of blood sugar and blood pressure are important but progression of retinopathy may occur despite all medical efforts. If diabetic retinopathy is detected early, photocoagulation by laser photocoagulation may stop continued damage. Even in advanced stages of the disease, it can reduce the chance that a patient will have severe visual loss.

Laser treatment is used to seal or obliterate the abnormal leaking blood vessels. This procedure focuses a powerful beam of laser light onto the damaged retina. Small bursts of the laser energy seal leaking vessels and form tiny scars inside the eye. The scars reduce new vessel growth and cause existing ones to shrink and close.

Laser treatments are usually carried out in an outpatient setting. They do not require special preparation or admission to hospital. Photocoagulation cannot be used successfully in all patients. Advanced cases with vitreous bleeding into the eye and scar tissue formation require a procedure called vitrectomy together with other sophisticated surgical procedures.

Various scientific studies have proven beyond doubt that proper medical eye care by ophthalmologists, laser photocoagulation and vitrectomy surgery are crucial in the preservation of sight in diabetic patients.

Successful treatment of diabetic retinopathy depends on early detection and treatment. All diabetics are advised to control their diabetes with diet and medication to delay or prevent the development of diabetic retinopathy and other complications. They are also advised to undergo a yearly eye examination.

* This is a general guide. If in doubt, please consult your doctor.