Dealing with the risk of diabetic eye disease
World Diabetes Day (WDD) is celebrated annually on November 14, led by the International Diabetes Federation (IDF). The WDD was created in 1991 by the IDF and the World Health Organisation (WHO) in response to growing concerns about the escalating health threat posed by diabetes.The WDD became an official United Nations Day in 2006 with the passage of United Nation Resolution 61/225.
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One of the complications of diabetic disease, namely diabetic eye disease is an area which in my opinion, has been given little attention yet it is threatening our population. Currently, there are approximately 415 million people on the globe living with the disease and by 2040, it is projected to rise to 642 million people.
Many documented and undocumented facts have shown that the disease is also on the increase in Ghana. The rise is attributed to change in our life style, aging population and relative improvement of healthcare. It is also known that our genetic make-up plays a big role. An estimated figure in 2015 shows that there are 266,200 diabetic cases between the ages of 20-79 in Ghana who are affected, thus translates into an incidence of 1.9 per cent . It also known that half of the people living with the disease is unknown.
What is diabetic eye disease?
Diabetic eye disease is a group of eye conditions that can affect people with diabetes. The eye is the earliest and most common complications of the diabetic disease compared to other complication. Diabetic eye disease among others includes cataract, glaucoma and diabetic retinopathy (most blinding complication of the disease).
Cataract is a clouding of the eye’s lens. Adults with diabetes are two to five times more likely than those without diabetes to develop cataract. Cataract also tends to develop at an earlier age in people with diabetes.
Glaucoma is a group of diseases that damage the eye’s optic nerve—the bundle of nerve fibers that connects the eye to the brain. Some types of glaucoma are associated with elevated pressure inside the eye. In adults, diabetes nearly doubles the risk of glaucoma.
All forms of diabetic eye disease have the potential to cause severe vision loss and blindness.
Diabetic Retinopathy
Diabetic Retinopathy (DR) is one of the most common cause of vision loss among people with diabetes and the leading cause of vision impairment and blindness among working-age population. It affects blood vessels in the light-sensitive tissue called the retina that lines the back of the eye.
From 1990–2010, DR ranked as the fifth most common cause of preventable blindness and moderate to severe visual impairment. In 2015, an estimated 415 million people worldwide lived with diabetes with over half of them with signs of DR, and a third of these are afflicted with Vision-Threatening Diabetic Retinopathy (VTDR). There are approximately 93 million people with DR, 17 million with proliferative DR, 21 million with diabetic macular edema and 28 million with vision – threatening DR worldwide. Longer diabetes duration and poorer glycemic and blood pressure control are strongly associated with DR. These data highlights the substantial worldwide public health burden of DR and the importance of modifiable risk factors in its occurrence.
Diabetic retinopathy is a complication of diabetes that causes damage to the blood vessels of the retina. DR can cause Diabetic Macular Edema (DME), this is when blood vessels in the retina leak fluid or bleed at the center part of the retina used for sharp, straight-ahead vision. This may lead to distortion and reduced vision. In its most advanced stage, poor blood circulation may lead to the development of growth factors that can cause new blood vessels and scar tissue to grow on the surface of the retina.
Vision may be lost because some of the retina tissue may die as a result of this inadequate blood supply. This stage of DR is called Proliferative Diabetic Retinopathy (PDR). The vessels bleed into the middle cavity of the eye, causing vision loss because light cannot reach the retina. Scar tissue formation can also pull on the retina, detaching it from the back of the eye, resulting in vision loss. Occasionally, these blood vessels and scar tissue may grow in the front of the eye, where fluid normally exits. When the fluid cannot escape, pressure can build in the eye, creating a rare type of glaucoma (neovascular glaucoma) that can damage vision even further and cause eye pain.
Symptoms
It is possible to have diabetic retinopathy for a long time without noticing symptoms until substantial damage has occurred. Symptoms may include, blurred of vision, difficulty reading, appearance of spots, known as “Floaters” in your vision. A person with diabetic retinopathy may also notice a shadow across the field of vision, eye pain or pressure, or difficulty with colour perception. Some patients may experience a partial or total loss of vision. It is important to note that diabetic retinopathy usually affects both eyes.
Risk factors
Anyone who has diabetes is at risk of developing DR. There are, however, additional factors that can increase the risk:
• Disease duration: the longer someone has diabetes, the greater the risk of developing DR.
• Poor control of blood sugar levels over time.
• High blood pressure.
• High cholesterol levels.
• Pregnancy in someone with diabetes can also result in changes in the retina.
Diagnostic investigations
Regular eye exams by the eye specialist (Ophthalmologist or Optometrist) are important for all newly diagnosed diabetics and especially for those who are at a higher risk for DR. It is advisable to see the eye doctor the first time you are diagnosed with the disease. Your eye doctor may refer you to a retina specialist.
The best way to diagnose DR is a dilated eye exam. The eye specialist (Ophthalmologist) will look for: swelling in the retina (diabetic macular edema), abnormal and new blood vessels or scar tissue on the surface of the retina (proliferative diabetic retinopathy).
Your eye specialist may take fundus photographs of the back of the eye to facilitate detection of DR and to document the retinopathy. He may do many other tests and procedures. If the doctor detects signs of DR, she/he often can determine how frequently follow-up examinations will be required in order to detect changes that would require treatments.
Treatment and drugs
As a result of major government and industry-sponsored studies, there are many surgical treatments for DR, including lasers to the retina or miniscule injections of medications into the middle cavity of the eye. These procedures can be done in an office or hospital setting to prevent, treat, or reverse damage from diabetes in the retina.
Research has shown that eye injections often—but not always in combination with laser treatment—result in better vision than laser treatment alone for patients with DME. The key to these treatments is their ability to block Vascular Endothelial Growth Factor (VEGF), a chemical signal in the body that stimulates blood vessel growth. Repeated doses of anti-VEGF medications may be needed to prevent blood vessels from leaking fluid and causing damage to the eye. Even if not all vision loss from DR can be prevented or treated at this time, patients usually are able to find ways to live with diminished vision.
Prevention
The following are ways to prevent diabetic retinopathy and vision loss caused by it:
Controlling of blood sugar levels through diet, exercise and medications. The better control of these levels, the less likely one will develop DR or have worsening of any pre-existing retinopathy. One of the best ways to monitor your sugar levels is by frequent blood checks that will help you keep your blood sugar levels in a target range.
Second, controlling of blood pressure and possibly your lipid levels can affect the impact of diabetes on your retina. It is extremely important for diabetic patients to maintain the eye examination schedule put in place by the retina specialist. Through early detection, the retina specialist can begin a treatment regimen to help prevent vision loss and slow the disease’s progression.
