Diabetes mellitus (DM) is a complex disease which can result in organ damage. Good control of diabetes is important to prevent the various complications associated with it, including Diabetic Retinopathy (DR).
With the increase in prevalence of DM globally, we expect to see an increase in DR cases too here in Malaysia. Sad to mention, that diabetic retinopathy is a leading cause of visual loss among adults of working age in Malaysia.
What is diabetic retinopathy?
DR is a complication of diabetes that affects the retina. It is caused by damage to the blood vessels of the retina. (The retina is the light-sensitive tissue at the back of the eye. A healthy retina is necessary to maintain good vision).
DR can develop in anyone who has type 1 diabetes or type 2 diabetes. Prevalence of DR is closely linked to the duration of diabetes. The longer you have diabetes the more likely you are to develop DR. Poor control of blood sugar is associated with higher risk of DR too.
What are the symptoms of diabetic retinopathy?
Often, there are no symptoms in the early stages of DR, nor is there any pain. DO NOT WAIT for symptoms.
Blurred vision may occur when the macula swells from leaking fluid. This condition is called macular edema.
If new blood vessels grow on the surface of the retina, they can bleed into the eye. Depending on the severity of the bleeding, the symptoms can vary from seeing few specks of floaters, blurred vision, fluctuating vision, difficulty in colour perception and total loss of vision.
Screening and early treatment can prevent substantial visual loss. To protect your vision, take prevention measures seriously. Start by carefully controlling your blood sugar level and have your eye checked for signs of DR. Be sure to have a comprehensive dilated eye exam at least once a year.
What are the risk factors for diabetic retinopathy?
All people with diabetes are at risk. These factors can increase your risk:
- Duration of diabetes – the longer you have diabetes, the greater your risk
- Poor control of blood sugar
- High cholesterol
- High blood pressure
How is diabetic retinopathy diagnosed?
DR can be diagnosed through a comprehensive eye examination. A detailed evaluation of the retina and macula will be carried out by your eye doctor. The eye examination includes:
Visual acuity test to determine the extent to which central vision has been affected
- Dilated eye exam. Dilating eyedrops are instilled to dilate your pupil. The retina and macula will be examined for signs of DR. After the examination, your near vision may remain blurred for several hours.
- Measurement of intraocular pressure
Supplemental testing includes:
- Retinal photography
- Fluorescein angiography to evaluate macular edema and abnormal blood vessel growth
- Optical Coherence Tomography to asses and monitor macular edema
How is diabetic retinopathy treated?
Treatment of DR varies depending on the extent of the disease. In early stages of DR, no treatment is needed unless you have macular edema.
Macular edema is treated with focal laser. Only when the disease advances to proliferative retinopathy, then a scatter laser treatment is needed to shrink the abnormal blood vessels. Because a high number of laser burns are necessary, two or more sessions of scatter laser are required to complete the treatment.
Injections of medications into the eye may be needed to decrease the macular edema or to stop the formation of new blood vessels. In more advanced cases, a surgery is needed to remove blood in the vitreous cavity or to repair the retinal detachment resulting from advanced diabetic retinopathy.
If you have diabetes, you can reduce your risk of getting diabetic retinopathy by doing the following:
- Manage your diabetes well. Besides controlling your sugar level, make healthy eating and physical exercise part of your daily routine.
- Monitor your blood sugar level. You may need to check and record your sugar level regularly - more frequent measurements are advised if you are under stress or ill. Ask your physician how frequent you need to test your sugar level, and take your oral diabetes medications or insulin as directed.
- Glycosylated haemoglobin test. This test reflects your average blood sugar level for the three-month period and is more reliable to indicate your sugar level control. Keeping your blood sugar level as close to normal may slow the progression of DR and reduce the need for treatment.
- Keep your cholesterol and blood pressure under control. If you have concurrent high cholesterol and blood pressure, keeping them under control will prevent the risk of progression of DR and your risk of vision loss.
- Pay attention to vision changes. Yearly dilated eye exams are important to detect early changes of DR. If you have DR changes, your eye doctor will see you more regularly depending on the stage of the DR. Contact your eye doctor right away if you have sudden vision changes or blurred vision or floaters.
- Stop smoking. Smoking increases your risk of various diabetes complications.
Diabetes retinopathy doesn't necessarily lead to poor vision. Taking an active role in diabetes management can go a long way towards preventing visual loss.