What is Diabetic Retinopathy?

Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease's affect on the retina is the main threat to vision. Most patients develop diabetic changes in the retina after approximately 5-20 years. The effect of diabetes on the eye is called diabetic retinopathy.

Diabetic retinopathy is the leading cause of blindness in young and middle-aged adults today. The longer a person has diabetes, the greater their chance of developing diabetic retinopathy. There are two types of diabetic retinopathy:

• Non-proliferative diabetic retinopathy (NPDR)
• Proliferative diabetic retinopathy (PDR)

NPDR, also known as background retinopathy, is an early stage of diabetic retinopathy and occurs when the tiny blood vessels of the retina are damaged and begin to bleed or leak fluid into the retina resulting in swelling (diabetic macular edema) and the formation of deposits known as exudates. Many people with diabetes develop mild NPDR often without any visual symptoms.

PDR carries the greatest risk of loss of vision and typically develops in eyes with advanced NPDR. PDR occurs when blood vessels on the retina or optic nerve become blocked consequently starving the retina of necessary nutrients. . New, fragile, vessels develop as the circulatory system attempts to maintain adequate oxygen levels within the retina. This is called neovascularization. Unfortunately, these delicate vessels hemorrhage easily. Blood may leak into the retina and vitreous, causing spots or floaters, along with decreased vision.

1. Vitreous hemorrhage - proliferating retinal blood vessels grow into the vitreous cavity and break down. Both the hemorrhaging and resultant scar tissue may interfere with vision.
2. Traditional retinal detachment - scar tissue in the vitreous and on the retina cause the retina to detach.
3. Tractional and rhegmatogenous retinal detachment - scar tissue creates a hole or tear in the retina causing it to detach.
4. Neovascular glaucoma - abnormal blood vessel growth on the iris blocks the flow of fluid out of the eye causing the pressure to increase and damaging the optic nerve.