Diabetic Retinopathy
What is diabetic retinopathy?
A person with diabetes is at risk for developing diabetic retinopathy
among other ophthalmic disorders. Diabetic retinopathy is the leading
cause of blindness in young and middle-aged adults today. The longer a
person has diabetes, the greater their chance of developing diabetic
retinopathy. There are two types of diabetic retinopathy:
- non-proliferative diabetic retinopathy (NPDR)
- proliferative diabetic retinopathy (PDR)
NPDR, also known as background retinopathy, is an early
stage of diabetic retinopathy and occurs when the tiny blood vessels of
the retina are damaged and begin to bleed or leak fluid into the retina
resulting in swelling (diabetic macular edema) and the formation of
deposits known as exudates. Many people with diabetes develop mild NPDR
often without any visual symptoms.
PDR carries the greatest risk of loss of vision and typically develops
in eyes with advanced NPDR. PDR occurs when blood vessels on the retina or
optic nerve become blocked consequently starving the retina of necessary
nutrients. In response, the retina grows more blood vessels
(neovascularization). Unfortunately these new vessels are abnormal and
cannot replenish the retina with normal blood flow.
PDR may lead to any one of the following:
- Vitreous hemorrhage - proliferating retinal blood vessels grow into
the vitreous cavity and break down. Both the hemorrhaging and resultant
scar tissue may interfere with vision.
- Traditional retinal detachment - scar tissue in the vitreous and on
the retina cause the retina to detach.
- Tractional and rhegmatogenous retinal detachment - scar tissue
creates a hole or tear in the retina causing it to detach.
- Neovascular glaucoma - abnormal blood vessel growth on the iris
blocks the flow of fluid out of the eye causing the pressure to increase
and damaging the optic nerve.
What are the symptoms of diabetic retinopathy?
Generally, people with mild NPDR do not have any visual loss. A
dilated eye exam is the only way to detect changes inside the eye before
loss of vision begins. People with diabetes should have an eye examination
at least once a year. More frequent exams may be necessary after diabetic
retinopathy is diagnosed.
People with PDR experience a broader range of symptoms. They may:
- see dark floaters
- experience loss of central or peripheral vision
- experience visual distortions or blurriness
- experience temporary or permanent vision loss
How is diabetic retinopathy diagnosed?
 Diabetic retinopathy is diagnosed by dilating the pupil and looking
inside the eye with an ophthalmoscope. If an ophthalmologist discovers
diabetic retinopathy, he or she may wish to order color photographs of the
retina through a test called fluorescein angiography. During this test, a
dye is injected into the arm and quickly travels throughout the blood
system. Once the dye reaches the blood vessels of the retina, a photograph
is taken of the eye. The dye allows the ophthalmologist to detect damaged
blood vessels that are leaking dye.
Can diabetic retinopathy be prevented?
The most effective overall strategy for diabetic retinopathy is to prevent it
as much as possible. Strict control of blood sugar levels will
significantly reduce the long-term loss of vision from retinopathy. With
improved diagnosis and treatment, only a small percentage of people with
retinopathy develop serious vision problems.
What are the current treatment options for a person with diabetic retinopathy?
Because the earliest stages of diabetic retinopathy include inflammation,
intraocular corticosteroids have been utilized with some success in selected
patients. This form of treatment includes the use of a long-acting
corticosteroid (triamcinolone acetonide) injected into the vitreous cavity
by way of a very tiny needle under topical (drops) anesthesia. This
treatment may reduce retinal swelling and improve visual acuity in patients
with diabetic macular edema. However, visual recovery may be limited and
the effect may last only 3 to 6 months after the treatment. Other clinical
trials on corticosteroids include a sustained-release drug delivery device
surgically implanted inside the eye to allow constant release of the
medication. In two larger multicenter clinical trials using sustained-release
steroid drug delivery devices, the Oculex Study is evaluating dexamethasone
and the Bausch and Lomb Study is testing fluocinolone acetonide.
What research is currently being conducted on diabetic retinopathy?
Two new medications are currently being investigated for diabetic retinopathy.
LY333531, a protein Kinase C-beta inhibitor (PKC-beta inhibitor) developed by Eli
Lilly and Company, is a promising new medication for preventing the progression of
diabetic retinopathy. A clinical trial on this medication does not yet have enough
data to make a general recommendation to change current management strategies with
laser surgery or pars plana vitrectomy. Similarly, Genetech is currently testing
Anti-Vascular Endothelial Growth Factors (anti-VEGF) drugs for wet age-related
macular degeneration. These anti-VEGF drugs may have future application for the
treatment of diabetic retinopathy.
What advantage does Bascom Palmer Eye Institute offer patients with diabetic retinopathy?
The 30 clinical faculty members at the Bascom Palmer Eye Institute have
accumulated years of clinical experience in the management of diabetic
retinopathy. Drs. Harry Flynn
and William Smiddy
have been active in diabetic retinopathy clinical studies for more than 12 years. At
the request of the American Academy of Ophthalmology, Drs. Flynn and Smiddy organized a
350-page monograph titled Diabetes and Ocular Disease: Past, Present and Future
Therapies. Diabetic patients also have a number of non-retinal abnormalities
including increased rates of cataract, glaucoma, ocular muscle abnormalities, corneal
diseases, and susceptibility to infection. The faculty at the Bascom Palmer Eye
Institute are familiar with these potential complications and have experience in the
management of these problems when they occur.
Who are the diabetic retinopathy specialists at Bascom
Palmer Eye Institute?
Thomas Albini, M.D.
John G. Clarkson, M.D.
Janet L. Davis, M.D.
Sander Dubovy, M.D.
Yale L. Fisher, M.D.
Harry W. Flynn, Jr., M.D.
Jaclyn L. Kovach, M.D.
Geeta Lalwani, M.D.
Wen-Hsiang Lee, M.D.
Andrew A. Moshfeghi, M.D.
Timothy G. Murray, M.D., M.B.A., F.A.C.S.
Philip J. Rosenfeld, M.D., Ph.D.
Stephen Schwartz, M.D., M.B.A.
William E. Smiddy, M.D.
Other Vitreo-Retinal Resources
American
Academy of Ophthalmology
Eye
Resources on the Internet
American
Diabetes Association
National Eye
Institute
Prevent
Blindness America
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