Blurred Vision due to Diabetes Underlying Cause
The underlying cause of diabetic retinopathy is unknown.
The blood vessels that provide the retina with nutrients and oxygen are very delicate, and can be damaged by elevated glucose levels in the bloodstream. Damaged vessels leak blood and fluid onto the retina. Damaged vessels can also block blood flow to the retina, damaging the retinal cells.
There are two types of diabetic retinopathy:
- Background diabetic retinopathy
- The early stage of diabetic eye disease.
- Tiny blood vessels leak blood, which appears as retinal hemorrhages.
- Tiny blood vessels leak fluid, which forms deposits called exudates.
- The presence of fluid in the retina can decrease visual clarity.
- Proliferative diabetic retinopathy
- The most serious form of diabetic eye disease.
- Progressive injury to the retinal vessels leads to blockages.
- The body reacts by forming new blood vessels in the retina. These vessels are abnormal and do not resupply the retina with adequate blood flow.
- The new vessels are fragile can bleed leading to a condition called vitreous hemorrhage.
- May also predispose the retina to retinal tears and retinal detachment.
Continue to Blurred Vision due to Diabetes Anatomy
- Bloomgarden ZT. Diabetic retinopathy and neuropathy. Diabetes Care. 2005 Apr;28(4):963-70. 
- Frank RN. Diabetic retinopathy. N Engl J Med. 2004 Jan 1;350(1):48-58. 
- Olson DE, Norris SL. Diabetes in older adults. Overview of AGS guidelines for the treatment of diabetes mellitus in geriatric populations. Geriatrics. 2004 Apr;59(4):18-24. 
- Sinclair SH, Malamut R, Delvecchio C, Li W. Diabetic retinopathy: treating systemic conditions aggressively can save sight. Cleve Clin J Med. 2005 May;72(5):447-54.