Diabetes is becoming much more prevalent around the globe. According to the International Diabetes Federation, approximately 425 million adults were living with diabetes in the year 2017 and 352 million more people were at risk of developing type 2 diabetes. By 2045 the number of people diagnosed is expected to rise to 629 million.
Diabetes is a leading cause of blindness as well as heart attack, stroke, kidney failure, neuropathy (nerve damage) and lower limb amputation. In fact, in 2017, diabetes was implicated in 4 million deaths worldwide! Nevertheless preventing complications from diabetes is possible with proper treatment, medication and regular medical screenings as well as improving your diet, physical activity and adopting a healthy lifestyle.
What is Diabetes?
Diabetes is a chronic disease in which the hormone insulin is either underproduced or ineffective in its ability to regulate blood sugar. Uncontrolled diabetes leads to hyperglycemia, or high blood sugar, which damages many systems in the body including the blood vessels and the nervous system.
How Does Diabetes Affect The Eyes?
Diabetic eye disease is a group of conditions which are caused, or worsened, by diabetes; including diabetic retinopathy, diabetic macular edema, glaucoma and cataracts. Diabetes increases the risk of cataracts by four times, and can increase dryness and reduce cornea sensation.
In diabetic retinopathy, over time, the tiny blood vessels become damaged, causing leakage, poor oxygen circulation, then scarring of the sensitive tissue within the retina.
The longer you have diabetes, and the longer your blood sugar levels remain uncontrolled, the higher the chances of developing diabetic eye disease. Unlike many other vision-threatening conditions which are more prevalent in older individuals, diabetic eye disease is one of the main causes of vision loss in the younger, working-age population. Unfortunately, these eye conditions can lead to blindness if not caught early and treated. In fact, 2.6% of blindness worldwide is due to diabetes.
As mentioned previously, diabetes can result in cumulative damage to the blood vessels in the retina, the light-sensitive tissue located at the back of the eye. This is called diabetic retinopathy.
The retina is responsible for converting the light it receives into visual signals that run along the optic nerve to the brain. High blood sugar levels can cause the blood vessels in the retina to leak or hemorrhage, causing bleeding and distorting vision. In advanced stages, new blood vessels may begin to grow on the retinal surface causing scarring and further damaging cells in the retina. Diabetic retinopathy can eventually lead to blindness.
Signs and Symptoms of Diabetic Retinopathy
The early stages of diabetic retinopathy often have no symptoms, which is why it’s vitally important to have frequent diabetic eye exams. With progression, one may start to notice the following symptoms:
- Blurred or fluctuating vision or vision loss
- Floaters (dark spots or strings that appear to float in your visual field)
- Blind spots
- Colour vision loss
There is no pain associated with diabetic retinopathy. If not controlled, the retinopathy can lead to macular edema and retinal detachment, two other serious conditions that threaten vision. Again, there are often NO signs or symptoms until more advanced stages.
A person with diabetes can do their part to control their blood sugar level. Following the physician’s medication plan, as well as diet and exercise recommendations can help reduce the risk and slow the progression of diabetic retinopathy.
Diabetic Macular Edema (DME)
Diabetic macular edema occurs when the macula, a part of the retina responsible for clear central vision, becomes full of fluid (edema). It is a complication of diabetic retinopathy that occurs in about half of patients, and causes vision loss.
Treatment for Diabetic Retinopathy and Diabetic Macular Edema
While vision loss from diabetic retinopathy and DME often can’t be restored, with early detection there are some preventative treatments available. Proliferative diabetic retinopathy (when the blood vessels begin to grow abnormally) can be treated by laser surgery, injections or a procedure called vitrectomy in which the vitreous gel within the eye is removed and replaced. This will treat bleeding caused by ruptured blood vessels. DME can be treated with injection therapy, laser surgery or corticosteroids.
Scar tissues caused by advanced retinopathy can lead to a retinal detachment in which the retina pulls away from the underlying tissue. This condition is a medical emergency and must be treated immediately as it can lead to permanent vision loss. Signs of a retinal detachment include a sudden onset of floaters or flashes in your vision.
Prevent Vision Loss from Diabetes
The best way to prevent vision loss from diabetic eye disease is early detection and treatment. Since there may be no symptoms in the early stages, regular diabetic eye exams are critical for early diagnosis. Keeping diabetes under control through exercise, diet, medication and regular monitoring will help to reduce the chances of vision loss and blindness.