Diabetic Retinopathy (NPDR)
If you have diabetes mellitus, your body does not use and store sugar
properly. Over time, diabetes 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 is referred to as diabetic retinopathy.
Nonproliferative diabetic retinopathy (NPDR), commonly known as
background retinopathy, is an early stage of diabetic retinopathy. In this
stage, tiny blood vessels within the retina leak blood or fluid. The leaking
fluid causes the retina to swell or to form deposits called exudates.
Many people with diabetes have mild NPDR, which usually does not affect
their vision. When vision is affected, it is the result of macular edema and/or
Macular edema is 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 fluid leaking from retinal blood vessels. It
is the most common cause of visual loss in diabetes. Vision loss may be mild to
severe, but even in the worst cases, peripheral (side) vision continues to
function. Laser treatment can be used to help control vision loss from macular
Macular ischemia occurs when small blood vessels
(capillaries) close. Vision blurs because the macula no longer receives
sufficient blood supply to work properly. Unfortunately, there are no effective
treatments for macular ischemia.
A medical eye examination is the only way to find changes inside your
eye. If your ophthalmologist finds diabetic retinopathy, he or she may order
color photographs of the retina or a special test called fluorescein
angiography to find out if you need treatment. In this test a dye is injected
in your arm and photos of your eye are taken to detect where fluid is leaking.
If you have diabetes, early detection of diabetic retinopathy is the best
protection against loss of vision. You can significantly lower your risk of
vision loss by maintaining strict control of your blood sugar and visiting your
ophthalmologist regularly. People with diabetes should schedule examinations at
least once a year. Pregnant women with diabetes should schedule an appointment
in the first trimester because retinopathy can progress quickly during
pregnancy. More frequent medical eye examinations may be necessary after the
diagnosis of diabetic retinopathy.
Diabetic Retinopathy (PDR)
retinopathy is a complication of diabetes caused by changes in the blood
vessels of the eye. If you have diabetes, your body does not use and store
sugar properly. High blood sugar levels create changes in the veins, arteries
and capillaries that carry blood throughout the body. This includes the tiny
blood vessels in the retina, the light-sensitive nerve layer that lines the
back of the eye.
In PDR, the retinal blood vessels
are so damaged they close off. In response, the retina grows new, fragile blood
vessels. Unfortunately, these new blood vessels are abnormal and grow on the
surface of the retina, so they do not resupply the retina with blood.
Occasionally, these new blood
vessels leak and cause a vitreous hemorrhage. Blood in the vitreous, the clear
gel-like substance that fills the inside of the eye, blocks light rays from
reaching the retina. A small amount of blood will cause dark floaters, while a
large hemorrhage might block all vision, leaving only light and dark
The new blood vessels can also
cause scar tissue to grow. The scar tissue shrinks, wrinkling and pulling on
the retina and distorting vision. If the pulling is severe, the macula may detach
from its normal position and cause vision loss.
Laser surgery may be used to
shrink the abnormal blood vessels and reduce the risk of bleeding. The body
will usually absorb blood from a vitreous hemorrhage, but that can take days,
months or even years. If the vitreous hemorrhage does not clear within a
reasonable time, or if a retinal detachment is detected, an operation called a
vitrectomy can be performed. During a vitrectomy, the eye surgeon removes the
hemorrhage and the abnormal blood vessels that caused the bleeding.
People with PDR sometimes have
no symptoms until it is too late to treat them. The retina may be badly injured
before there is any change in vision. There is considerable evidence to suggest
that rigorous control of blood sugar decreases the chance of developing serious
proliferative diabetic retinopathy.
Because PDR often has no
symptoms, if you have any form of diabetes you should have your eyes examined
regularly by an ophthalmologist.