Diabetic retinopathy, the most common diabetic eye disease, occurs when blood vessels in the retina become damaged due to persistently elevated blood sugar. Sometimes these vessels swell and leak fluid or even close off completely. In other cases, abnormal new blood vessels grow on the surface of the retina. These changes can lead to significant damage to vision. Yearly follow-up is imperative so your doctor can monitor for any of those abnormalities and initiate timely treatment. Blood glucose level must also be monitored on a continuous basis.