Diabetes, a leading cause of vision loss, damages blood vessels throughout the body, including the eye. Types of damage done can vary, depending on how long a person has had diabetes and how good their blood glucose control is. The longer a person has been diabetic and the higher their blood sugars, the more damage occurs to the eye. Diabetics usually don't develop diabetic retinopathy, damage to the blood vessels in the retina, until they've had diabetes for 10 years or more, All About Vision says.
Non-Proliferative Diabetic Retinopathy
The first stage of diabetic retinopathy, called non-proliferative diabetic retinopathy, or NPDR, dilates the blood vessels in the retina, which causes bleeding. These leaks, called microaneurysms, damage the retina. Non-proliferative diabetic retinopathy normally doesn't need treatment unless macular edema, swelling around the macula, the central point of vision, develops, but needs close and frequent eye exams to watch for progression to proliferative diabetic retinopathy, the American Diabetes Association advises.
Proliferative Diabetic Retinopathy
Proliferative diabetic retinopathy, a later stage of diabetic damage to the retina, results in abnormal blood vessels growth throughout the retina. Noticeable vision loss may not occur until considerable damage to the retina has occurred, the American Diabetes Association warns. Proliferative diabetic retinopathy is treated with scattered laser called pan retinal photocoagulation, to seal off the leaking vessels and prevent scarring in the retina.
Macular Edema
Abnormal blood vessels can grow underneath and around the macula, the central point of vision on the retina, seriously disrupting vision. Macular edema is treated by focal laser, which reduces vision loss by up to 50 percent, the National Eye Institute states. Injecting medications to reduce the swelling in the macula, such as corticosteroids, helps preserve vision in more severe cases of macular edema. Injecting medications such as Avastin and Lucentis, called anti VEGF medications that disrupt blood flow to the abnormal vessels, reduces formation of new blood vessels.
Vitreous Hemorrhage
Vitreous hemorrhage occurs when blood leaks into the vitreous, the normally clear jelly that forms the center part of the eyeball, from abnormal blood vessels that form at its edge. Blood clouding the vitreous severely decreases vision. Doctors may choose to watch and see if the blood dissipates or absorbs over time, or may recommend that the vitreous gel be removed surgically, a procedure called a vitrectomy, All About Vision explains. Sterile saline replaces the gel.
Other Eye Problems
Swelling and scarring within the retina can lead to retinal detachment, separation of the retina from the wall of the eye, resulting in permanent vision loss in the area of attachment if not promptly treated with laser, cryotherapy or surgery. Diabetics also increases the risk of developing cataracts, clouding of the lens in the eye or glaucoma, high intraocular pressure that can damage the optic nerve and cause severe vision loss, according to the National Eye Institute.
