Looking at diabetic retinopathy straight in the eye

Diabetes is one of the leading causes of blindness. Doctors couldn’t stress this enough.

Fact is, patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma but the main threat to vision is the disease’s effect on the retina. That effect is called diabetic retinopathy.

American Eye Center’s Dr. Arnold Salud, clinical associate professor, UP-PGH College of Medicine, explains it very clearly, "What happens basically is this: From the heart, there’s a major blood vessel that goes on to the brain as its main supply. But on its way to the brain, there’s a main branch that goes into the eye, which we call ophthalmic artery. It goes into the optic nerve, shoots into the eye and branches out into veins. In diabetics, what’s affected is the smallest branches or what you call capillaries. When you have high blood sugar, the end or long-term effect is those small blood vessels are clogged up so they cannot do their function, which is to distribute oxygen through the red blood cells. Now, when you don’t bring enough oxygen, the response of the retina would be to allow growth of additional blood vessels that can bring in more oxygen. But what happens is that those blood vessels that grow burst and eventually cause all those bleedings because they’re abnormal, weak wall structures. When they burst — the content of the eye is supposed to be a clear gel — light cannot reach the retina so you cannot see."

In medicalese, people develop a condition called macular edema. This occurs when the damaged blood vessels leak fluid and lipids into the macula, the part of the retina that lets us see detail, making it swell. As a result, vision is blurred.

Clear and simple fact, isn’t it? But sad to say, you could be suffering from diabetic retinopathy and not know it. "Your eyes may be clear, you may have 20-20 vision but you may already have blood in your retina," the good doctor warns.

He hastens to add, "You should not rely on signs because once you have some or most of the signs, it means you already have a problem. Once you’re diagnosed as diabetic, even if you have no eye problems, you should go for an eye checkup. Your best bet is what is called the well-baby checkup, you bring a baby for checkup even if the baby’s well."

Dr. Salud sees at least two patients a day with diabetic retinopathy at the state-of-the-art American Eye Center, located at Level 5 of Shangri-La Plaza, where he holds clinic twice a week. His patients are mostly over 50 years old. Consultation fee is reasonably priced at P400.

"Our referral system is not as sophisticated as the US’," he laments. "In the States, once you’re diagnosed, there’s automatic referral. If you’re diabetic, you shouldn’t only go to a diabetologist, you should also go to a general practitioner. If you have glaucoma, you should go to a glaucoma specialist."

Let’s take a closer look at diabetic retinopathy via this Q & A:

Who is at risk for this disease?

People with Type I diabetes (juvenile onset) and Type II diabetes (adult onset). Diabetic retinopathy may also be a problem for pregnant women with diabetes. Thus, it is recommended that pregnant women have dilated eye examinations each trimester.

What are the symptoms?

Often, diabetic retinopathy has no early warning signs. Sometimes though you may have blurred vision because of macular edema and find it hard to do things like read and drive. In some cases, your vision will get better or worse during the day.

How is it detected?

It is detected during an eye examination that includes visual acuity test, pupil dilation, ophthalmoscopy and tonometry.

How is it treated?

There are two treatments for diabetic retinopathy: laser surgery and vitrectomy. In laser surgery, the doctor will aim a high-energy beam of light directly onto the damaged blood vessels. This seals the vessels and stops them from leaking. Laser surgery is used to stabilize vision and prevent further damage, not necessarily to improve it. But instead of laser surgery, you may need an eye operation called vitrectomy which involves removing the cloudy vitreous and replacing it with a salt solution. It is especially effective in people with insulin-dependent diabetes who are at greater risk of blindness from hemorrhage of the eye.

What can you do to protect your vision?

People with diabetes are urged to have an eye examination through dilated pupils at least once a year or more often if they have serious retinopathy. According to a recent study by the Diabetes Control and Complications Trial, better control of blood sugar levels slows the onset and progression of retinopathy.