The retina is the part of the eye that responds to light to trigger the impulses the brain perceives as images. Retinopathy is damage to this layer of cells, which has small blood vessels that are easily damaged. In the case of diabetic retinopathy, the damage is triggered by complications from diabetes. Diabetic retinopathy screening is an important tool to help prevent blindness from such damage. This type of screening involves a standard eye test, having the pupils dilated so as to better view the retina, and possibly additional high tech optical screens of the eye.
According to the American Diabetes Association (ADA), diabetic retinopathy is thought to be responsible for most of the cases of blindness diagnosed in adults from 20 to 74 years old. This is highly unfortunate, since diabetic retinopathy screening can identify damage to the eye in the early stages before there is any noticeable change in vision. Treatment is still possible in most cases if the retinopathy is detected early.
Diabetic retinopathy is predicted to occur in most people who have had diabetes for a great length of time. The majority of Type 1 diabetics are predicted to acquire this condition eventually. Almost 21% of Type 2 diabetics are diagnosed with diabetic retinopathy when their diabetes is first discovered, but well managed glucose levels can minimize the chances of developing this disorder.
The disease can start out with swelling of the eyes and damage to the optical nerve, known as neuropathy. With proliferative retinopathy, new blood vessels start to grow in the retina. This can cause the retina to become detached, and these blood vessels may bleed into the eye. Both of these pathological states can damage vision.
When one sees an ophthalmologist for diabetic retinopathy screening, the first step is to have a standard vision test with an eye chart. After that, the eye doctor will put special drops in the eyes to cause the pupils to grow larger. This technique of ophthalmic screening is known as dilation. It enables the eye care professional to better view the retina and determine if there are any signs of damage. The examination will involve viewing the eyes through a magnifying lens, preferably using a special optometric device rather than a hand-held magnifying glass.
After the eyes have been dilated, vision will be blurry for several hours. It will be difficult to read or use a computer. The eyes will also be extremely sensitive to light. The ophthalmologist will provide disposable sunglasses, but patients who wear corrective lenses are encouraged to bring their own prescription sunglasses. It is possible to drive after the screening, but some people choose to wait until their vision has returned to normal before operating a vehicle.
For many people, the standard vision test and pupil dilation represent their complete diabetic retinopathy screening. Dilation can identify early stages of diabetic eye damage, such as swelling and optical nerve damage. The more advanced proliferative retinopathy is readily diagnosed with this method.
An additional method of ophthalmic screening includes a technique similar to ultrasound known as optical coherence tomography. There are also screening programs in which digital photographs are taken of the eye to provide a sharp, close image to better diagnose diabetic retinopathy. In the UK, such screening is performed on diabetic patients yearly. These screening methods are non-invasive. All diabetic patients should have their eyes screened yearly for diabetic retinopathy.