High blood sugar levels can damage blood vessels in the retina, the nerve layer at the back of the eye that carries visual information to the brain. This damage to retinal vessels is referred to as Diabetic Retinopathy.
Types Of Diabetic Retinopathy
Nonproliferative Diabetic Retinopathy (NPDR)
This is sometimes referred to as background retinopathy. It is an early stage in which tiny blood vessels in the retina leak fluid or blood. This leaking can cause retinal swelling and the formation of deposits known as exudates.
Patients with NPDR often have no vision changes unless they develop edema or ischemia of the macula or both.
Macular Edema - Swelling or thickening of the macula, a small area in the center of the retina that allows us to see fine details clearly. The swelling is caused by leaking from retinal vessels. Macular edema is the most common cause of vision loss in diabetes. Even though central vision loss can become severe in some patients, peripheral vision often remains intact.
Macular Ischemia - This occurs when the macula has not received adequate blood supply to remain functioning normally due to small capillaries closing.
Proliferative Diabetic Retinopathy (PDR)
Proliferative Diabetic Retinopathy is present when abnormal new vessels (neovascularization) begin growing on the surface of the retina or optic nerve. The primary cause of PDR is widespread closure of retinal blood vessels. This stimulates new blood vessel growth in an attempt to restore circulation.
Unfortunately, the new abnormal blood vessels do not resupply the retina with normal blood flow. The new vessels are often accompanied by scar tissue that may cause wrinkling or detachment of the retina.
Complications Associated With PDR:
Vitreous Hemorrhage - Fragile new vessels may bleed into the vitreous, a clear, gel-like substance that fills the center of the eye. If the vitreous hemorrhage is small, a person might only see a few new, dark floaters. A very large hemorrhage may completely block out all vision in the eye. When the blood clears or is removed surgically, vision may return to normal provided the macula has not been damaged.
Tractional Retinal Detachment - When PDR is present, scar tissue may shrink, pulling the retina from its normal position. This may lead to wrinkling of the macular distorting vision. Significant vision may occur if the traction leads to a detached retina.
Neovascular Glaucoma - Occasionally, extensive new blood vessel growth can lead to neovascularization of the iris. This can block drainage of fluid from the eye leading to elevated eye pressure. This neovascular glaucoma must be treated to prevent damage to the optic nerve.
How Is Diabetic Retinopathy Treated?
The best treatment is to prevent the development of retinopathy as much as possible. Strict control of your blood sugars will significantly reduce the long-term risk of vision loss. If high blood pressure and kidney problems are present, they need to treated effectively.
Medical Treatment - Injections of anti-VEGF medication in the eye can stop the growth of new blood vessels and subsequent bleeding. Sometimes a steroid medication is used as well.
Laser Surgery - Laser is often recommended for people with macular edema, PDR, and neovascular glaucoma.
Vitrectomy - Performed to remove a blood-filled vitreous that is then replaced with a clear solution. Vitrectomy often prevents further bleeding by removing the abnormal vessels on the retinal surface during the procedure.
Nonproliferative Diabetic Retinopathy
Proliferative Diabetic Retinopathy
Image Of An Eye That Has Undergone
to the Entire Peripheral Retina
Note The White Laser Scars.