DIABETES AND YOUR EYES

Diabetes is a chronic disease in which the body does not effectively process blood sugar. Insulin is a hormone that regulates blood glucose and delivers it to the cells all over the body. With diabetes, the body either does not produce or does not respond effectively to insulin, leading to high levels of glucose or sugar in the bloodstream, which in turn can lead to damage to the blood vessels and nerves throughout the body.

The eyes are particularly vulnerable to fluctuations in blood sugar levels, increasing the risk of a variety of eye problems. Over time, changes occur in the tiny blood vessels in the retina at the back of the eye, making it harder for the blood to flow and causing the blood vessels to become blocked, bleed or leak fluid.

The longer a person has diabetes, the more likely they are to develop diabetic eye disease, a group of eye conditions caused by high blood sugar levels. The risk is significantly reduced if blood sugar levels are controlled, and the impact on vision decreases if the problem is detected and managed early.

It is important for people with diabetes to have regular comprehensive eye examinations as there are often no early symptoms, but signs of eye disease can be noticed by an optometrist before it has progressed, and symptoms become apparent. Early detection and treatment can help protect vision.

DIABETIC RETINOPATHY

Diabetic retinopathy is the most common cause of vision loss in people with diabetes, affecting 1 in 3 people, and is the leading cause of blindness in adults.

It typically progresses through four stages from mild, moderate and severe non-proliferative to proliferative retinopathy. It occurs gradually with no early symptoms until it has progressed to later stages, when symptoms may include eye floaters, blurred vision, distorted vision or intermittent changes in vision.

After a prolonged period of high blood sugar levels, the blood vessels in the retina weaken, bulge or leak, depriving the retina of oxygen and essential nutrients. As the damaged vessels become blocked, new abnormal blood vessels grow on the surface of the retina.

While diabetic retinopathy cannot be reversed, treatment alongside diabetes management can stabilise it.

DIABETIC MACULAR EDEMA

The macula is the area of the retina responsible for sharp central vision. Macular edema is swelling of the macula due to fluid leaking from the blood vessels in the retina, leading to blurred or distorted vision and the gradual loss of central vision. It affects about 1 in 15 people with diabetes. In many cases, early treatment can slow its progress and prevent it from getting worse.

GLAUCOMA

Glaucoma is a common eye condition, but the risk of developing glaucoma doubles in people who have diabetes.

Neovascular glaucoma is caused by high blood sugar levels which damage the blood vessels of the retina and result in the creation of abnormal new blood vessels which block drainage of fluid from the eye, increasing eye pressure.

This increased pressure affects the optic nerve, causing changes in vision and gradual vision loss.

Noticeable symptoms may not be present in its early stages, but if it is detected early during a dilated eye examination, it can be treated and prevented from progressing.

CATARACTS

Cataracts are a common eye condition affecting millions of people worldwide, but people with diabetes are more likely to develop cataracts at a younger age than other people and they tend to progress more rapidly.

RETINAL DETACHMENT

Diabetic retinopathy can result in scar tissue forming in the back of the eye. This can cause the retina to pull away and detach from the back of the eye, leading to sudden and severe vision problems which require emergency medical intervention.

SWELLING OF THE EYE LENS

If blood sugar levels change rapidly from low to normal, the shape of the eye’s lens can be affected, causing blurred vision. Vision returns to normal once blood sugar stabilises.

The best way to lower the risk of diabetic eye disease is to control blood sugar, blood pressure and cholesterol levels. Regular exercise and a healthy diet have an essential role to play in managing these levels. If you have been diagnosed with diabetes, it is very important to have regular eye examinations to evaluate eye health and monitor any changes in the eyes, particularly in the early stages of the condition. While treatment will not reverse vision damage that may have occurred, the earlier vision problems are detected and treated, the better the chance of slowing down or even stopping the progression of the damage to the retina.