How
do I know whether I have diabetic retinopathy?
Early stages of
diabetic retinopathy do not cause any symptoms unless the central portion, the
macula is affected. Many times even with advanced proliferative retinopathy the vision may be completely normal. However as the retinopathy progresses
severe vision loss and even blindness may occur. It is best not to wait for symptoms to occur.
A complete eye check up must be done periodically even if you have good vision.
Symptoms of
diabetic retinopathy are-
Distorted
central vision
Blurred vision
Difficulty in
reading small print
Black spots or
lines in vision
Blacked out or
blank areas in the field of vision
Total loss of
vision
How
is diabetic retinopathy detected?
A complete eye
check up which includes examination of the retina after instillation of eye
drops to widen the pupil of the eye can detect diabetic retinopathy. The doctor
uses an instrument known as the indirect ophthalmoscope along with a magnifying
lens to look inside your eye and examine the retina. The changes of diabetic
retinopathy can be easily seen on this examination. The treating doctor may advise a
few investigations to confirm the presence or absence of new vessels, and
swelling of the macular area.
What
are the tests done for diabetic retinopathy?
Fluorescein
angiography-
The doctor may
advise a test called as fluorescein angiography to check for presence of
leakage from abnormal blood vessels or damaged capillaries and loss of small
blood vessels. In this test, first the pupils of your eyes are dilated using
eye drops. Then a dye called as sodium fluorescein is injected in the vein in
the arm. Photos are taken serially every 1-2 seconds as the dye passes through
the retinal vessels. After 10 minutes a late phase photo is taken. This test
shows the leaking areas and helps in planning and execution of laser treatment.
Some patients experience nausea after the injection of sodium fluorescein.
Otherwise the test is safe and serious complications are extremely rare.
 |
| Fundus photo of diabetic retinopathy |
 |
| Fluorescein angiogram of the same eye shows leakage |
Optical
Coherence Tomography-
Optical
Coherence Tomography, OCT for short, is another test routinely advised for
patients with diabetic retinopathy, especially those with macular involvement.
This is a non-invasive scan test which gives a cross sectional view of the
central retina known as the macula. This test gives microscopic details about
the macular area. It can show the retinal thickening and accumulation of fluid
in the retina and below it. Moreover the thickness of retina can be measured.
Serial scans can show whether treatment has been effective in controlling the
retinal swelling or not.
 |
| OCT scan shows thickening of the macular area and fluid spaces in the retina and under the retina |
How
often do I need to undergo these tests?
In early
nonproliferative diabetic retinopathy generally no tests are required. If the
retinopathy progresses to proliferative stage or if macular edema develops,
these tests are done more frequently. If you are on treatment for macular
edema, the OCT may be done every month and fluorescein angiography may be done
every 3-6 months.
