Health Sense: Don't go blind from diabetes -- detect the symptoms early

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Health Sense: Don't go blind from diabetes -- detect the symptoms early
January 9, 2009
Jakarta Post

No one wants to go blind, and fortunately, in many cases, it can be avoided.

Given the growing affluence in Asia, and the lifestyle changes and increased longevity that comes with it, more people are suffering from diabetic retinopathy, glaucoma and age-related macular degeneration which can lead to severe loss of vision or even blindness.

"In fact, diabetic retinopathy is the most common cause of blindness in the adult working population in developed countries," says ophthalmologist Ian Yeo Yew San, a consultant with the Singapore National Eye Center.

Up to 80 percent of blindness can be avoided. Often, it is the result of complications from diabetes or other medical conditions.

According to the 2004 National Health Survey in Singapore, 8.9 percent of males were diabetic, compared to 7.6 percent of females.

Indian diabetics topped the list at 15.3 percent, compared with the Malays at 11 percent, and the Chinese at 7.1. These figures should hold true with Asians elsewhere who have similar lifestyles.

Diabetic retinopathy is a complication of diabetes that results from damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina).

When you have diabetes, your body does not use sugar (glucose) properly.

If your blood sugar level is too high, your natural lens may swell, which can blur your vision. Eventually, too much sugar in your blood can damage the tiny blood vessels (capillaries) that nourish the retina. This can result in diabetic retinopathy.

The longer you have been diabetic, the higher your chances are that your blood vessels in your eyes will become damaged.

"About 60 percent of patients who have had diabetes for 15 years or longer will have some blood vessel damage in their eyes, and a certain percentage of them are at risk of becoming blind," Yeo said.

At first, diabetic retinopathy may cause no symptoms or only mild vision problems. Eventually, however, diabetic retinopathy can result in blindness.

As the condition progresses, its symptoms, which usually affect both eyes, may include: * Spots floating in your vision * Blurred vision * Dark streaks or a red film that blocks your vision * Poor night vision * Vision loss

As part of the eye exam, your doctor may do a retinal photography test called fluorescein angiography.

First, your doctor will dilate your pupils and take pictures of the inside of your eyes. Then a special dye will be injected into a vein in your arm. More pictures will be taken as the dye circulates through your eyes.

Your doctor can use the images to pinpoint blood vessels that are closed, have broken down or are leaking fluid.

Your doctor also may request an optical coherence tomography (OCT) exam. This imaging test provides cross-sectional images of the retina that shows the thickness of the retina and whether fluid has leaked into the retinal tissue.

There are several types of diabetic retinopathy.

Background retinopathy is an early stage and progresses slowly over the years. Tiny blood spots or fatty deposits may appear on the retina.

The majority of patients do not develop vision loss except for a gradual blurring of vision which may not be noticeable. In some patients, blood vessels leak at the macula -- the part of the retina responsible for central vision, causing loss of vision.

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 nerves.

These vessels tend to rupture and bleed into the vitreous cavity. Or, scar tissues may grow from the ruptured blood vessels which will contract and pull on the retina, detaching it -- resulting in loss of vision.

If diabetic retinopathy is detected early, photocoagulation by laser treatment may stop it from getting worse.

In cases where the disease is in an advanced stage, the treatment can reduce the chances of having a severe loss of vision.

Treatment involves using laser beams to seal the abnormal blood vessels from leaking and forming tiny scars on the retina. These scars will reduce new vessel growth and cause existing ones to shrink and close up. The treatment can be done on an outpatient basis.

Advanced cases of diabetic retinopathy are treated by a procedure called vitrectomy to remove blood from the center of the eye (vitreous) and scar tissue that may be tugging on the retina.

Often, vitrectomy is followed or accompanied by laser treatment. This procedure is done under local or general anesthesia.

"Successful treatment of diabetic retinopathy depends on early detection and treatment."

Prevention is better than cure

Preventable eye conditions such as diabetic retinopathy can be detected early and properly treated to stop them from getting worse.

"This is why there are active programs to screen for these eye diseases. We recommend that patients who are diabetic go for diabetic retinal photography or retinal assessment so that if anything, they can be treated early and hopefully save their eyesight," says ophthalmologist Ian Yeo Yew San, a consultant with the Singapore National Eye Center.

Fortunately for Yeo's patient, Syed Mustaffa B. Syed Hassan, who has been diabetic for more than 10 years, his diabetic retinopathy was detected early and it was successfully treated.

Like most, he was not unaware of it, but when he underwent surgery for a hand injury three years ago, the doctor noticed blood clots in his eyes.

Mustaffa was referred to the Singapore National Eye Center where the operation was performed, one eye at a time.

"Now I can see the bus numbers, watch TV and read," Mustaffa said.

Yeo's advice for diabetic patients is 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 have yearly eye examinations.

The Singapore National Eye Center sees 250,000 outpatients, performs 14,000 major eye surgeries and 13,000 laser procedures every year.

The center performs over 1,200 vitreo-retinal surgeries annually. A strict quality assurance program instituted by the center ensures excellent results, comparable to other world-class eye institutions.