How does diabetic retinopathy cause vision loss?
Blood vessels damaged from diabetic retinopathy can cause vision loss in two ways:
- Fragile, abnormal blood vessels can develop and leak blood into the center of the eye, blurring vision. This is proliferative retinopathy and is the fourth and most advanced stage of the disease.
- Fluid can leak into the center of the macula, the part of the eye where sharp, straight-ahead vision occurs. The fluid makes the macula swell, blurring vision. This condition is called macular edema. It can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses. About half of the people with proliferative retinopathy also have macular edema.
Does diabetic retinopathy have any symptoms?
Diabetic retinopathy often has no early warning signs. Don’t wait for symptoms. Be sure to have a comprehensive dilated eye exam at least once a year.
What are the symptoms of proliferative retinopathy if bleeding occurs?
At first, you will see a few specks of blood, or spots, “floating” in your vision. If spots occur, see your eye care professional as soon as possible. You may need treatment before more serious bleeding occurs. Hemorrhages tend to happen more than once, often during sleep.
Sometimes, without treatment, the spots clear, and your sight will improve. However, bleeding can reoccur and cause severely blurred vision. You need to be examined by your eye care professional at the first sign of blurred vision, before more bleeding occurs.
If left untreated, proliferative retinopathy can cause severe vision loss and even blindness. Also, the earlier you receive treatment, the more likely treatment will be effective.
How are macular edema and diabetic retinopathy detected?
Macular edema and diabetic retinopathy are detected during a comprehensive eye exam that includes the following:
- Visual acuity test: An eye chart test that measures how well you see at various distances.
- Dilated eye exam: An eye examination where drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your closeup vision may remain blurred for several hours.
- Tonometry: An instrument measures the pressure inside your eye. Numbing drops may be applied to your eye for this test.
Your eye care professional checks your retina for early signs of the disease, including—
- Leaking blood vessels
- Retinal swelling (macular edema)
- Pale, fatty deposits on the retina (signs of leaking blood vessels)
- Damaged nerve tissue
- Any changes to the blood vessels
If your eye care professional believes you need treatment for macular edema, he or she may suggest a fluorescein angiogram. In this test, a special dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your retina. The test allows your eye care professional to identify any leaking blood vessels and to recommend treatment.
“Diabetic retinopathy often has no early warning signs. Don’t wait for symptoms. Be sure to have a comprehensive dilated eye exam at least once a year.”