| What
is Diabetes? Diabetes
is one of the leading causes of visual loss in the United
States. Visual problems become more likely the longer that
diabetes has been present. Given enough time, about 85%
of diabetics will have some eye problems. Over many years,
good blood sugar control does limit, but does not prevent,
eye problems.
Diabetes affects the eye in two main ways. First, excess
sugar can be trapped in the eye’s lens causing blurry
vision, a change in glasses prescription, and cataracts
(cloudy lens). Diabetics frequently require more changes
in their glasses prescription and need earlier cataract
surgery than the average patient. Second, diabetes causes
the smallest blood vessels in the back of the eye to close
down or leak. Damage here, in the retina, causes the most
severe threat to vision.
What is Diabetic Retinopathy?
The eye is like a tiny camera,
and the retina is the “film” in the back of
this camera. The center of the retina is a tiny spot called
the “macula”, which supplies all of our sharp,
central vision. The earliest form of diabetic retinal damage
is called “background diabetic retinopathy”.
About 50% of patients with diabetes for 10-15 years have
some signs of this such as bleeding, or swollen pockets
within the retina. If these swollen areas affect the macula,
dim or blurry vision may result.
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If the eye disease worsens,
areas of the retina may not get enough blood. The eye responds
by growing thin new vessels. This is called “proliferative
diabetic retinopathy”. Unfortunately, these new vessels
frequently break open and bleed, filling the eye with blood
and stimulating scar tissue to grow, sometimes leading to
retinal detachment. The early stages of this condition can
be treated with the laser. More advanced disease often requires
invasive surgery, called “vitrectomy”, which
involves removal of blood, scar tissue, and abnormal vessels
within the eye and repair of retinal detachment.
How is Diabetic Retinopathy Diagnosed?
In some
cases, advanced damage may be present without the patient
even being aware. Also, most treatments for diabetic eye
disease work  better
at preventing and controlling the diabetic retinopathy than
at reversing it once it is well established. Because of
this, it is very important for diabetics to have a regular,
complete eye examination that should include drops to dilate
the pupil. We recommend regular eye examinations, in most
cases once a year, to detect diabetic eye problems before
the patient recognizes visual problems. We routinely report
information about your exam to your primary care physician
and/or diabetes specialist to keep them updated on this
part of your health. In between scheduled eye examinations,
patients should report any changes in their vision, such
as increased fuzziness, new floating spots, restricted side
vision, or pain.
In addition to regular eye examinations,
the diabetic patient should work with his or her physicians
to control the blood sugar level and keep blood pressure
under control. Tests to determine how well the kidneys are
working may also be needed. Over years, this has been shown
to reduce the severity of diabetic complications. Diabetic
patients who become pregnant should have even more frequent
examinations of the retina.
How
is Diabetic Retinopathy treated?
When significant retinopathy
is detected, a special test called fluorescein angiography
is sometimes performed. This is a photographic test of the
retina and does not involve X-rays. After color pictures
are taken, a yellow dye called fluorescein is injected into
the arm vein and photographed as it passes through the retinal
vessels. This provides a very detailed "road map"
of the retina, identifying any weakened or abnormal blood
vessels. This test is helpful in deciding whether laser
treatment is needed and in guiding that treatment.
Laser surgery is the most common treatment for diabetic
retinopathy. Laser is a highly focused beam of light that
can be used to cauterize leaky blood vessels or stimulate
abnormal new vessels to shrink and stop bleeding. Laser
surgery is done in the office, using anesthetic eye drops
or an anesthetic injection. Usually laser involves little
or no discomfort, and patients go home immediately after
treatment. Post-operative discomfort, if it occurs, is usually
controlled with non-prescription pain medication such as
Tylenol TM or Advil TM.
Laser surgery for retinal swelling is called focal or grid
laser therapy. This is effective in preventing further vision
loss and may result in some visual improvement. Once this
treatment has been performed, it may take several weeks
or months for the swelling to fully drain away. Occasionally,
more leaky spots develop requiring repeated focal treatment.
Abnormal new vessel growth can be treated with panretinal
photocoagulation. In this type of laser surgery, a large
number of laser spots are placed in the side portions of
the retina. This causes abnormal new vessels to shrink and
reduces the risk of vision loss from bleeding or retinal
detachment.
Laser surgery is designed to stabilize or improve vision.
It cuts in half the risk of severe vision loss. Even if
vision is not improved, laser therapy may help to limit
visual loss that would have occurred without treatment.
Some patients experience side effects of laser, including:
-Mild loss of side vision
-Blurry vision or spots in the vision
-Difficulty seeing in dim light
-Sensitivity to light
These side effects, when noticed at all, are usually mild
and temporary, but on occasion they may persist. Even then,
this is far better than the serious visual loss that can
result without laser treatment.
Although laser treatment is very successful at stabilizing
diabetic retinopathy, it is not a cure. Sometimes, damage
may progress despite laser treatment. This damage can include
persisting hemorrhage in the central jelly, called Vitreous
Hemorrhage (shown at right), or scar tissue and detachment
of the retina. Vitrectomy surgery may be needed if further
hemorrhage or damage to the retina occurs in spite of laser
or if laser has not been performed before these more serious
problems occur. This is an operation in which the jelly
in the back of the eye along with any scar tissue or blood
is removed. This is usually a very successful procedure
that is well tolerated by the eye. Your doctor can discuss
your case with you individually.
If you have any questions, please call us at 913-261-2020.
Back
to the Retina Center
View
the Diabetic Retinopathy Video Presentation
Related Links:
American Diabetes Association
www.diabetes.org
National Eye Institute
www.nei.nih.gov/health/diabetic/retinopathy.asp
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