Introduction to diabetic retinopathy
Diabetic retinopathy is one of the complications, which arises due to ‘long-term diabetes’. It causes damage to the blood vessels of light sensitive tissue behind the retina of the eye. Initially, diabetic retinopathy shows no symptoms apart from mild vision problems, but gradually can lead to blindness. Diabetic retinopathy affects people suffering from type 1 diabetes or type 2 diabetes.
Epidemiology (Occurrence of diabetic retinopathy in different groups)
World Health Organization estimates that 150 million people suffer from diabetes, worldwide and also suggests that the number will be doubled by the year 2025.1 Diabetic retinopathy is not seen in the initial 3–5 years after being diagnosed with type 1 diabetes. Other studies indicate that nearly 97.5% of patients with type 1 diabetes will have retinopathy after 15 years.2 With better diet control and bringing about a modification in the risk factors, diabetic retinopathy can be less threatening as predicted earlier.3 In children with diabetes, retinopathy is usually not seen before puberty.4
Classification of diabetic retinopathy
Diabetic retinopathy can be classified as:
- Nonproliferative diabetic retinopathy–Nonproliferative diabetic retinopathy can be mild, moderate or severe.6 In this condition, the blood vessels of the retina weaken. As the condition advances large retinal veins begin to dilate. The nerve fibers of the retina also swell.
- Proliferative diabetic retinopathy–In this condition abnormal blood vessels or a new blood vessels grow or leak a jelly-like substance, which fills the center of the eye. This gradually causes the formation of a scar tissue, which causes the retina to detach from behind the eye. This interferes in the normal blood flow and damages the optic nerve.
Symptoms of diabetic retinopathy
No symptoms are observed in the initial stages of diabetic retinopathy. Diabetic retinopathy affects both the eyes. In the later stages, the following symptoms can be observed.
- Spots floating during vision
- Poor night vision
- Dark streaks or a red film that blocks vision
- Vision loss
- Blurred vision
Risk Factors for diabetic retinopathy
Following are some risk factors identified, which cause diabetic retinopathy.5
- Poor glycemic control
- Long-standing diabetes
- Smoking ( Read more about how to quit smoking)
Diabetic macular edema is a condition, where the retina of the eye is thickened due to an intra-retinal accumulation of fluid within the macula. This condition causes loss of vision in people suffering from diabetic retinopathy.
Treatment of diabetic retinopathy
The following are the types of treatment are suggested for diabetic retinopathy.
- Focal laser treatment—This is called as photocoagulation, and done to stop the leakage of blood and fluid in the eye.
- Scatter laser treatment—This is also called as pan retinal photocoagulation and done to shrink the abnormal blood vessel.
- Vitrectomy—This is a surgical procedure done to eliminate the blood from the center of the eye (vitreous) and the scar tissue.7
Management of diabetic retinopathy
Diabetic retinopathy can be managed by:
- Controlled blood sugar levels8
- Controlled blood pressure
- Modifying the risk factors
- Regular eye examinations
- King H, Aubert RE, Herman WH. Global burden of diabetes, 1995-2025: prevalence, numerical estimates, and projections. Diabes Care. 1998; 21: 1414–1431.
- Klein R, Klein BE, Moss SE, et al. The Wisconsin epidemiologic study of diabetic retinopathy, II: prevalence and risk of diabetic retinopathy when age at diagnosis is less than 30 years. Arch Ophthalmol. 1984; 102: 520–526.
- Henricsson M, Nystrom L, Blohme G, et al. The incidence of retinopathy 10 years after diagnosis in young adult people with diabetes: results from the nationwide population-based Diabetes Incidence Study in Sweden (DISS). Diabetes Care. 2003; 26: 349–354.
- Jackson RL, Ide CH, Guthrie RA, et al. Retinopathy in adolescents and young adults with onset of insulin-dependent diabetes in childhood. Ophthalmology. 1982; 89: 7–13.
- Yoshida Y, Hagura R, Hara Y, et al. Risk factors for the development of diabetic retinopathy in Japanese type 2 diabetic patients. Diabetes Res Clin Prac. 2001; 51: 195–203.
- Early Treatment Diabetic Retinopathy Study Research Group. Early photocoagulation for diabetic retinopathy. ETDRS Report 9. Ophthalmology. 1991; 98: 766–785.
- Patel JI, Jykin PG, Schadt M. Pars plana vitrectomy with and without peeling of the internal limiting membrane for diabetic macular edema. Retina. 2006; 26: 5–13.
- The UK Prospective Diabetes Study Group. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet. 1998; 352: 837–853.