How does diabetes harm the eye?

If you are diabetic your body does not use and store sugar properly. High blood-sugar levels can damage blood vessels in the retina, the nerve layer at the back of the eye that senses light and helps to send images to the brain. The damage to retinal vessels in referred to as diabetic retinopathy.

 

How is diabetic retinopathy diagnosed?

A dilated medical eye exam is the only way to detect changes inside your eye. An ophthalmologist can often diagnose and treat serious retinopathy before you are aware of any vision problems.

 

How is diabetic retinopathy treated?

The best treatment is to prevent the development of retinopathy as much as possible. Strict control of your blood sugar will significantly reduce the long-term risk of vision loss from diabetic retinopathy. Laser surgery is often recommended for people with macular edema, proliferative diabetic retinopathy, and neovascular glaucoma. However, laser surgery does not cure diabetic retinopathy. Multiple laser treatments over time are sometimes necessary.

 

When should I schedule an examination if I have diabetes?

Diabetics should be seen at least once a year, and more frequently after a diagnosis of diabetic retinopathy. Pregnant women with diabetes should be seen during the first trimester, because retinopathy can progress quickly during pregnancy.

 

If you need eyeglasses, it is important that your blood sugar be consistently under control. Rapid changes in blood sugar can cause fluctuating vision in both eyes even if retinopathy is not present. You should see the ophthalmologist promptly if you have vision changes that:

 

• Affect only one eye
• Last more than a few days
• Are not associated with a change in blood sugar

 

Do the eyes have anything to do with learning disabilities?

It may seem easy to blame reading problems on the eyes, but learning disabilities are caused by the brain, not the eyes. Children with learning disabilities do not have more visual problems than children without learning disabilities. Your eye functions like a camera. After the eye "takes the picture," the image is sent to your brain by the optic nerve. Your eyes do not understand what they see any more than a camera understands the photograph it takes. Until the photo is processed, it has no meaning. Similarly, until your brain interprets images seem by your eyes, the image has no meaning.

 

What are refractive errors?

For our eyes to be able to see, light rays must be bent or "refracted" so they can focus on the retina, the nerve layer that lines the back of the eye. The cornea and the lens refract light rays. The retina receives the picture formed by these light rays and sends the image to the brain through the optic nerve. A refractive error means that the shape of your eye doesn't refract the light properly, so that the image you see is blurred.

 

• Myopia (nearsightedness): A myopic eye is longer than normal, so that the light rays focus in the front of the retina. Close objects look clear but distant objects appear blurred.

 

• Hyperopia (farsightedness): A hyperopic eye is shorter than normal. Light from close objects, such as the page of a book, cannot focus clearly on the retina.

 

• Astigmatism (distorted vision): The cornea is the clear front window of the eye. A normal cornea is round and smooth, like a basketball. When you have astigmatism, the cornea curves more in one direction than in the other, like a football. Astigmatism distorts or blurs vision for both near and far objects. You can have astigmatism in combination with myopia or hyperopia.

 

• Presbyopia (need for bifocals): When you are young, the lens in your eye is soft and flexible. The lens of the eye changes its shape easily, allowing you to focus on objects both close and far away. After the age of 40, the lens becomes more rigid. Because the lens can't change shape as easily as it once did, it is more difficult to read at close range. This is perfectly normal.

 

What is glaucoma?

Glaucoma is a leading cause of blindness in the United States. But the loss of sight from glaucoma is preventable if you get treatment early enough. Glaucoma is a disease of the optic nerve. The optic nerve carries the images we see to the brain. Many people know that glaucoma has something to do with pressure inside the eye. The higher the pressure inside the eye, the greater the chance of damage to the optic nerve. The optic nerve is like an electric cable containing a huge number of wires. Glaucoma can damage nerve fiber, causing blind spots to develop. Often, people don't notice these blind areas until much optic nerve damage has already occurred. Early detection and treatment by your ophthalmologist are the keys to preventing optic nerve damage and blindness from glaucoma.