“I have diabetes. How does it affect my eyes?”

Darren Dohman, O.D.

Since November is National Diabetes Month, I thought I would talk about diabetes and how it can affect the eyes. Diabetes mellitus is a metabolic disease characterized by high blood glucose (sugar) levels that result from the body not producing insulin (type 1) or the body not responding to the insulin that is produced (type 2). Diabetes is becoming one of the most common diseases in the US and currently affects 26 million Americans, with 79 million more at risk for developing type 2 diabetes.

Diabetes can affect the eyes in a number of different ways. One of the more common things that we see in our practice is vision fluctuation. Increased blood glucose over time can cause an accumulation of fluid in the crystalline lens inside the eye. This can lead to a shift in the glasses prescription and to blurred vision.

Someone with diabetes will also be 40% more likely to develop glaucoma. Glaucoma is an eye disease which causes a loss of optic nerve tissue in the back of the eye, resulting in a loss of peripheral or side vision.

A diabetic patient will also be 60% more likely to develop cataracts. A cataract is when the normally clear crystalline lens inside the eye becomes cloudy, which doesn't allow light to pass through it. This leads to blurred or dim vision. Diabetics may get cataracts at a younger age and they may progress faster than someone who does not have diabetes.

The most serious complication from diabetes regarding the eyes is the development of diabetic retinopathy (DR). There are two types, nonproliferative and proliferative. Nonproliferative DR occurs in the early stages. This is when the tiny blood vessels in the back of the eye become weakened and you get tiny bulges in the vessel walls called microaneurysms. Eventually, fluid leaks out of these weakened vessels causing swelling in the back of the eye. With nonproliferative DR, a patient may have mild symptoms or be symptom-free.

The other form of diabetic retinopathy is called proliferative DR. This is what occurs in the more advanced stages. With this form, the blood vessels become damaged and blocked leading to an oxygen-deprived retina. The body responds by growing new, fragile blood vessels along with accompanying fibrous tissue. These weak blood vessels can leak blood, which can block vision. This is called a vitreous hemorrhage. The new fibrous tissue can also cause scaring of the retina, which can pull and distort the retina. This can lead to a retinal detachment.

Symptoms of diabetic retinopathy may include blurred vision, seeing spots or seeing floaters; however, in the early stages it is possible to be symptom-free. There are a few treatment options for DR. In some cases, we monitor the retinas and have the patient try to better control their blood glucose levels. In certain cases, laser treatment can be done to seal leaky blood vessels. There are also injectable drugs to stop the formation of new blood vessels. In more severe cases, a vitrectomy can be performed. This is a surgery where the jelly-like fluid inside the eye is removed.

As you can see, there are a number of ways that diabetes can affect the eyes. This is why it is important to have your eyes checked each year by your eye doctor.