Diabetes is a disease that occurs when the pancreas does not produce an adequate amount of insulin or enough insulin is present but cannot be used properly. Insulin is a hormone that regulates the amount of glucose (sugar) in the blood. Diabetes can affect both adults and children. Patients with diabetes are more likely to develop eye problems such as glaucoma and cataracts.
Diabetic retinopathy is a condition caused by diabetic changes in the retina over time. The disease affects the tiny blood vessels in the eye by not allowing them to supply blood to all of the portions of the retina. The result of defective blood vessels is to leak small amounts of blood and fluid within the retina causing it to not function properly and can eventually result in vision loss. The retinal changes are seen in most patients after 20 years of having diabetes.A good reference to read more on diabetic retinopathy is http://www.nei.nih.gov/health/diabetic/retinopathy.asp