Home

About Diabetes

Complications

Warning Signs

Screening Test

Donate Now

E-Lerts™ Index

Latest News

Diabetes Terms

Health & Fitness

Online Press Center

Meet Mr. Diabetes^®

Wake Up And Walk^® Tour

Headlines & Stories

About Us - Contact Info

Message Board

Links

Save Your Sight: Preventing Vision Loss from Diabetes
posted 05/14/04
By Christine Haran

While senior citizens can expect some decline in their sight, vision loss is rarely a problem for younger people. But now that people are being diagnosed with diabetes at younger ages, diabetes-related vision loss is also occurring in middle-aged people. Sometimes vision problems are even the first sign of the disease.

A study published in the April issue of the Archives of Ophthalmology found that more than 4 million US adults aged 40 or older have diabetic retinopathy, a leading cause of blindness. Retinopathy occurs when high blood sugar levels damage blood vessels in the retina, which is the tissue at the back of the eye.

"The results of our study are important for public policy because they demonstrate that there's a large need for management and detection of eye disease in people with diabetes," says John H. Kempen, MD, PhD, an assistant professor of ophthalmology and epidemiology at the Johns Hopkins University and coordinator of study, which was authored by the Eye Diseases Prevalence Research Group.

Below, Dr. Kempen discusses the effectiveness of laser treatments and the importance of regular eye exams and consist control of blood sugar levels.

What kinds of vision problems do people with diabetes experience?
People with diabetes can develop a progressive condition called diabetic retinopathy, and it can cause either moderate or severe vision loss. Diabetic retinopathy is caused by high blood sugar levels. These high levels of sugar lead to a lack of blood supply to parts of the retina and also to leakage of fluid through the blood vessels in the retina. The leakage of fluid can cause swelling in the retina called macular edema that can lead to mild to moderate vision loss.

In the advanced stage of retinopathy known as proliferative retinopathy, the lack of blood supply can cause new, abnormal blood vessels to grow. It can also cause secondary damage such as retinal detachment or bleeding into the eye, leading to severe vision loss.

What are the risk factors for diabetic retinopathy?
High blood sugar is perhaps the most important factor, but high blood pressure and high lipid levels such as cholesterol also substantially increase the risk of getting diabetic retinopathy. So all three need to be controlled.

Because the prevalence of diabetes increases with age, diabetic retinopathy is more common in older people. But the other diseases we studied that are typically diseases of elderly people (cataracts, glaucoma and age-related macular degeneration) are strongly related to increased age, whereas diabetic retinopathy is more related to time with diabetes. So often people are diagnosed with diabetes at a young age, and therefore we see diabetic retinopathy in people aged 40 and older.

Are there early warning signs of diabetic retinopathy?
There can be, but the big problem with the disease is that it's often silent until suddenly major vision loss occurs. People might notice that their vision's getting blurry or a sudden onset of floating spots in their vision. These signs may indicate substantially advanced retinopathy.

Is retinopathy ever a first sign of diabetes?
Yes, in the population-based studies that have been done, a number of people who had diabetic retinopathy had not realized they had diabetes.

How often should people be screened for retinopathy?
Some studies have found that only 41 percent of people with diabetes are getting annual eye exams. It's recommended that everybody with type 2 diabetes, or the adult-onset type of diabetes, be screened annually for diabetic retinopathy and persons with type 1 diabetes should be screened annually, beginning five years after they were diagnosed with diabetes.

What does that eye exam involve?
Generally, a complete eye exam is done, but the key part of the exam is to examine the retina while the pupil is dilated. This involves what is called indirect ophthalmoscopy, which allows me to look through a lens at the retina, so I get a panoramic view of all the different parts of the retina.

It's best to be screened on a regular basis. Clinical experience suggests that there are a number of people who come in too late, or at a point where we're sort of picking up pieces rather than preventing things from going wrong.

How is diabetic retinopathy treated?
Laser treatment for diabetic retinopathy has been the subject of some of the most successful clinical trials ever done in the field of ophthalmology because the risk of progressing to severe vision loss from diabetic retinopathy can be reduced by as much as 90 percent.

There are also a number of promising pharmacologic treatments for diabetic retinopathy in development, although none of them have been approved by the Food and Drug Administration as of yet.

Who is eligible for laser treatment and what does it involve?
Laser treatment is available to people with certain kinds of diabetic retinopathy. If someone develops clinically significant macular edema, or swelling of the retina, they are treated with what's called focal laser treatment or grid laser treatment. This involves making small little burns in the retina that are aimed at leaky blood vessels to prevent them from leaking. If a person develops increased leaking over time or new areas of leakage, there might be a need for subsequent laser treatments.

The advanced stage of retinopathy, or proliferative retinopathy, is treated with another kind of laser, so the demand for blood supply is reduced and the drive to develop the new blood vessels is removed. This usually leads to regression of the disease and often it's not necessary to give further treatments.

Are there side effects of laser treatment?
Laser treatment for people with proliferative disease can cause people to have slightly reduced subjective color vision, maybe more difficulty seeing at night and maybe a loss of about one line on the vision chart. That's compared to 50 percent of people developing visual acuity of 20/800 or worse within a few years if they don't get the treatment. So there's a tremendous tradeoff there.

The laser treatment for clinically significant macular edema has fewer side effects, although people will often describe that there are little spots that are missing or reduced in their vision in one eye or the other.

What is your overall advice to people with diabetes with regard to their eye health?
There are two things they can do to reduce the risk of blindness. The most important thing is to try to prevent diabetic retinopathy from occurring by controlling their blood sugar, controlling hypertension, if it exists, and controlling their blood lipids, such as cholesterol, if they're abnormal. The other thing is to come for the eye exams, which enables the ophthalmologist to provide treatment to prevent severe vision loss.

So both primary prevention and secondary prevention are strongly recommended. The primary prevention can also prevent the numerous other complications of diabetes that can occur, too, such as kidney disease, nerve disease and higher risk of heart problems.

Source: Healthology, Inc.

May News Article Index