Don’t let diabetes ruin your eyesight

Yemurai Machirori Correspondent
Diabetes is one of the leading causes of irreversible blindness worldwide, and, it is the most common cause of blindness in people younger than 65. In addition to being a leading cause of blindness, diabetic eye disease encompasses a wide range of problems that can affect the eyes.

Diabetes may cause a reversible, temporary blurring of the vision, or it can cause a severe, permanent loss of vision. Diabetes also increases the risk of developing cataracts and glaucoma. Ironically, some people may not even realise that they have had diabetes for several years until they begin to experience problems with their eyes or vision.

Severe diabetic eye disease which refers to a group of eye problems that are faced with diabetic people most commonly develops in people who have had diabetes for many years and who have had little or poor control of their blood sugars over that period of time.

Diabetic eye disease usually includes diabetic retinopathy, which basically refers to the blood vessels in the retina. The eye cataract which involves clouding of the eye`s lens is also recognised as part of the major eye problems affecting people with diabetes. Lastly, an increase in fluid pressure inside the eye that will eventually lead to optic nerve damage and a loss of vision (glaucoma) is also a result of diabetes that is not being well controlled even though eye cataracts and glaucoma may also affect people who do not suffer from diabetes.

According to the Mayo Clinic, too much sugar in your blood, over time, can lead to the blockage of the tiny blood vessels that nourish the retina, cutting off its blood supply and as a result, the eye attempts to grow new blood vessels. However, these new blood vessels don’t develop properly and can leak easily.

Diabetes retinopathy usually happens over a period of time, even though it progresses faster in people with uncontrolled diabetes.

Also, people who have lived longer with diabetes (both Type 1 and Type 2) have a higher risk of developing diabetic retinopathy. The Mayo Clinic says that approximately 90 percent of people living with Type 1 diabetes will have some degree of retinopathy after 10 years of living with diabetes, and about 67 percent of people living with Type 2 diabetes and are not on insulin will also have a certain degree of retinopathy within the same period of time.

During the first stages of retinopathy, damage is limited to tiny bulges (microaneurysms) in the blood vessel walls. Although these can leak blood and fluid, they do not usually affect vision. The longer you have had diabetes, the greater your chance of developing retinopathy.

This can damage the blood vessels that supply the most sensitive part of the retina, called the macula, which distinguishes colours and focuses your eyes for tasks such as reading and writing. If fluid leaks into the macula, it can cause swelling (macular oedema), leading to some loss of vision. You may not be able to see objects clearly at a distance, or see things in fine detail, such as small print in a document.

When retinopathy reaches more advanced stages, some of the blood vessels that supply your retina will become blocked. In an attempt to restore the blood supply, new blood vessels will start to form. However, they are unstable and prone to bleeding, which can cause blurred and patchy vision. Over time, this bleeding can lead to scar tissue forming, which can pull your retina out of position. This is known as retinal detachment, and can lead to a darkening of vision, floaters and, if left untreated, blindness.

In order for people with diabetes to avoid getting diabetic retinopathy, health professionals strongly advise that they have the following kept in the expected ranges:

If you have diabetes and your blood glucose level is high, you have a higher risk of developing retinopathy. Blood glucose levels are measured using the HbA1C test. HbA1C is a form of haemoglobin and is the oxygen-carrying substance that is found in red blood cells and has glucose attached to it.

The haemoglobin A1c test, which is also called HbA1c, glycaeted haemoglobin test, or glycohemoglobin, is an important blood test that shows how well your diabetes is being controlled. This test provides an average of one`s blood sugar control over the past two to three months.

Therefore, people with diabetes should have this test every three months to determine whether their blood sugars have reached the target level of control. Those who have their diabetes under good control may be able to wait longer between the blood tests, but experts recommend checking at least two times a year.

If a person has both diabetes and high blood pressure, they have a higher risk of developing advanced retinopathy. Therefore, taking steps to prevent high blood pressure, such as giving up smoking and cutting down on salt in your diet, can help reduce your risk of developing retinopathy.

Important tips to remember include, but not limited to, diabetic eye screening at least once a year, early laser treatment, good control of sugar since blood pressure and cholesterol reduces the risk of diabetes related sight loss.