Diabetic eye disorders are one of the first noticeable signs of a diabetic condition. To understand eye disorders it is important to have a basic understanding of the human eye. The curved clear area at the front of the eye is the cornea, which focuses light and protects the inner eye. Behind the cornea is the anterior chamber containing a protective liquid called the aqueous humor, followed by the pupil, lens, center of the eye, and retina. The retina is responsible for recording images and sending them to the brain as electrical signals. A specialized portion of the retina responsible for seeing details is the macula.
There are three types of diabetic eye disorders each affecting a different part of the eye. Glaucoma refers to pressure in the aqueous humor, anterior chambers, and blood vessels serving the retina and optic nerve. Cataracts are a clouding of the lens of the eye, effecting vision.
While cataracts and glaucoma afflict individuals without diabetes, according to the American Diabetic Association persons suffering from diabetes are 40% more likely have glaucoma and 60% more likely to have cataracts than those without diabetes. The third type, diabetic retinopathy, is an umbrella term for diabetic eye disorders affecting the retina.
Diabetic Eye Disorders: Retinopathy
Diabetic retinopathy, the most common of the diabetic eye disorders, is a leading cause of blindness in American adults according to the National Eye Institute. Retinopathy is categorized into two types: nonproliferative in which the blood vessels at the back of the eye swell and form pouches, often causing leakage onto the macula (macular edema), and vision loss or damage; proliferative, the most severe form, occurs when damaged blood vessels close entirely causing weaker ones to grow, which in turn can leak, create scar tissue, and ultimately cause retinal detachment. The National Eye Institute estimates, “40 to 45 percent of Americans diagnosed with diabetes have some stage of diabetic retinopathy” while the American Diabetes Association states “almost everyone with type 1 diabetes will eventually have nonproliferative retinopathy”. Thus, it is extremely important to have regular dilated eye exams, particularly if you are pregnant, as retinopathy often develops without visible symptoms.
Relationship Between Glucose Levels and Diabetic Eye Disorders
As with most diabetes complications, diet plays a significant role when treating diabetic eye disorders. The Diabetes Control and Complications Trial (DCCT) gave significant evidence that tight control of blood sugar levels “slows the onset and progression of retinopathy”. The DCCT also evidenced that controlling blood sugar levels also reduced the need for eye surgery. Evidence also suggests that controlling blood pressure and cholesterol levels protect against diabetic eye disorders.
