March 12, 2019

DIABETIC RETINOPATHY: What You Need to Know

Diabetes is a chronic disease which, if not well managed, can result in complications such as eye disease (diabetic retinopathy), heart disease, kidney disease, nerve damage and problems with erection (impotence).

Retinopathy means damage to the retina. It is caused by prolonged high blood sugars that damage the small blood vessels. The retina is a part of the eyes that senses light and sends images to the brain. Good blood sugar control, regular eye exams and early treatment will reduce your risk of eye damage.

Retinopathy is very common among people with diabetes. One in three people with diabetes have diabetic retinopathy and one in 10 people with diabetes will develop a vision-threatening form of the disease.

Diabetic Retinopathy (eye disease) can affect many parts of the eye, including the retina, macula, lens and the optic nerve

Types of Diabetic Retinopathy

Did you know that diabetic retinopathy can increase the risk of glaucoma? This happens when the normal flow of fluid out of the eye is blocked by new abnormal blood vessels growing in the front part of the eye. This leads to pressure build up that can damage the nerve that sends images from the eyes to the brain. These can ultimately lead to blindness.

Diabetic retinopathy progresses through stages.

Early stages include:

• Macular edema: Part of the retina that helps you to see colour, becomes swollen
• Non-Proliferative Diabetic Retinopathy (NPDR): Damaged blood vessels in the retina begin to leak fluid and small amounts of blood and cholesterol.

Late stages include:

• Proliferative diabetic retinopathy (PDR): Blood vessels in the retina close and causes decrease in blood flow. Because of this, the retina will start to grow new abnormal blood vessels.
• Vitreous hemorrhage: New blood vessels bleed into the vitreous cavity. If the bleeding is small, the individual might see a few dark spots (floaters) or stands that look like cobwebs or clouded vision. If it is serious, it might block vision completely. The blood may take weeks or months to clear.
• Tractional retinal detachment: When new abnormal blood vessels grow, they result in scar tissue which can shrink causing the retina to tear or detach. The affected person could experience spots floating in vision or flashes of light or severe vision loss or blindness if not treated on time.

RISK FACTORS:

Factors that increase the risk for retinopathy for people with type 2 diabetes:

• Poorly controlled diabetes
• Duration of diabetes (the longer you have diabetes, the greater your risk of diabetic retinopathy)
• High blood pressure (Hypertension)
• Kidney disease (Nephropathy)
• High cholesterol (Hyperlipidemia)
• Low hemoglobin (red blood cells)
• Smoking

SYMPTOMS:

• Blurred vision
• Flashes of light in your field of vision
• Floaters (spots or dark strings floating in your vision)
• Impaired colour vision
• Blotches or spots in vision
• Poor night vision
• Sudden loss of vision

DIAGNOSIS:

Having an eye test done is the only way to find out if you have diabetic retinopathy. The eye doctor will make you look at some letters on a chart or picture chart. This measures your eyes’ ability to focus and see details at various distances. It helps to detect if there is vision loss. This is known as a visual acuity test.

Pressure inside your eyes will be measured to detect glaucoma. This test is known as Tonometry. Eye drops will be put in your eyes to make the pupil dilate (widen) to allow the doctor see the back of the eyes. Then a camera will be used to take the picture of the back of your eyes. This test does not hurt. When going for your eye appointment, it will be a good idea to take sunglasses with you. After the eye drops have been put in your eyes, your eyes will be more sensitive to light; this effect wears off after several hours.

Another test that can be done is called fluorescein angiogram. The eye is dilated with eye drops and pictures of the inside of the eyes are taken. Then, a special dye is injected into your arm and more pictures are taken as the dye circulates through your eyes. This test will help show the eye doctor if there are any closed, broken down or leaking blood vessels.

PREVENTION: 

Preventing diabetes related eye damage is always better than trying to treat it. Ways to prevent it include:

1) Visiting your eye doctor at least once a year for a diabetes eye exam or as recommended by your eye doctor. Diabetes eye exam (retinopathy screening) is covered by your OHIP.
a. Get a referral from your family doctor. If you do not have OHIP, discuss your options with your diabetes team.
2) Maintain good blood sugar levels (A1C < 7.0% for most people)
3) Control your blood pressure (under 130/80 mmHg)
4) Control your cholesterol (LDL under 2.0 mmol/L)
5) Take your medications as prescribed by your doctor
6) Stop smoking
7) Do regular physical activity; eat healthily and maintain a healthy body weight
8) Manage your stress

Ask your healthcare team for help!

Last but not least…

1. Even if your vision seems fine, you need to see your eye doctor every year for an eye exam.
2. When you have diabetes and are planning to become pregnant or are pregnant, you need to see your eye doctor because retinopathy can worsen with pregnancy.
3. If your vision suddenly changes or becomes blurry or hazy, you need to see your doctor immediately.

Click on this link to view a video about retinopathy:

https://www.youtube.com/watch?time_continue=94&v=wWXkEavu9YQ

References:

Altomare F., Kherani, A., Lovshin J (2018) Retinopathy. Canadian Journal of Diabetes 41(1) S210-216
Boyd, K & Vemulakonda G. A “What Is Diabetic Retinopathy?” American Academy of Ophthalmology, 4 Dec. 2018,http://www.aao.org/eye-health/diseases/what-is-diabetic-retinopathy.
“Eye Damage (Diabetic Retinopathy).” Diabetes Canadian. http://www.diabetes.ca/diabetes-and-you/complications/eye-damage-diabetic-retinopathy
“Facts About Diabetic Eye Disease.” National Eye Institute, U.S. Department of Health and Human Services, 1 Sept. 2015, https://nei.nih.gov/health/diabetic/retinopathy
Turbert, David, and Robert H Janigian Jr. “Non-Proliferative Diabetic Retinopathy (NPDR) Vision Simulator.” American Academy of Ophthalmology, 11 Sept. 2018, www.aao.org/eye-health/diseases/non-proliferative-diabetic-retinopathy-vision-simu-2.

“What Are the Stages of Diabetic Retinopathy?” The Eye Patch Club | Prevent Blindness, www.preventblindness.org/what-are-stages-diabetic-retinopathy

Image reference: https://nei.nih.gov/health/diabetic/retinopathy