Diabetic Eye Disease
Robert M. Knape, M.D.
Objectives
• Recognize the importance of diabetic eye disease
as a public health problem
• Discuss diabetic retinopathy as a leading cause of
blindness in developed countries
• Identify the risk factors for diabetic retinopathy
• Describe the stages of diabetic retinopathy
• Understand the role of risk factor control and
annual dilated eye exams in the prevention of
vision loss
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Diabetes Mellitus
Diabetes is a characterized by high blood glucose
levels and results from defects in the body's ability
to produce and/or use insulin.
• Type 1 Diabetes is usually diagnosed in children
and young adults, and was previously known as
juvenile diabetes. In type 1 diabetes, the body does
not produce insulin. Approximately 5% of people
with diabetes have this form of the disease.
• In Type 2 Diabetes, the most common type of DM,
the body either produces insufficient insulin, or the
cells do not respond to the insulin.
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The healthy eye
Cornea
• Light rays enter the eye
through the cornea, pupil
and lens.
Lens
• The light is focused on the
retina, the light-sensitive
tissue lining the back of the
eye.
Retina
• The retina converts the light
rays into impulses that are
sent to your brain, where
they are recognized as
images.
The Human Eye = Camera
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The retina
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Diabetes and the eye
• Diabetics are more likely to develop
cataracts (a clouding of the natural lens of
the eye).
• Diabetics can develop a severe type of
glaucoma (increased eye pressure
damaging the optic nerve).
• Diabetics can develop diabetic retinopathy
(damage to the fragile blood vessels of the
retina).*
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What is diabetic retinopathy (DR)?
• DR is caused by the progressive
dysfunction of retinal blood vessels
from chronic hyperglycemia.
• DR can be a complication of diabetes
type 1 or 2.
• DR is initially asymptomatic, but can
eventually cause decreased vision and
blindness.
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Normal retina
Diabetic retinopathy
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How common is diabetic retinopathy?
• The total number of people with
diabetes is projected to rise from 285
million in 2010 to 439 million in 2030.
• DR is responsible for 1.8 million of
the 37 million cases of blindness
throughout the world.
• DR is the leading cause of blindness
in people of working age in
industrialized countries.
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Causes of Global Blindness (WHO 2002)
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Millions of people
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10
8
6
4
2
0
A. Foster S.Resnikoff. The impact of vision 2020 on global blindness. Eye 2005; 19:1133-1135
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Diabetic retinopathy in diabetics
• The best predictor of diabetic retinopathy is the
duration of the disease.
• After 20 years of diabetes, nearly 99% of patients
with type 1 diabetes and 60% with type 2 have
some degree of diabetic retinopathy.
• 33% of patients with diabetes have signs of
diabetic retinopathy.
• People with diabetes are 25 times more likely to
become blind than the general population.
http://www.aao.org/eyecare/news/upload/Eye-Health-Fact-Sheet.pdf
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Prevalence of Diabetic Retinopathy after 20
Years of Diagnosis
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What are the symptoms of DR?
Diabetic retinopathy is asymptomatic in early stages of
the disease. As the disease progresses, symptoms may
include:
• blurred vision
• floaters
• fluctuating vision
• distorted vision
• dark areas in the vision
• poor night vision
• impaired color vision
• partial or total loss of vision
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What are the types of diabetic retinopathy?
There are two main subtypes of DR.
• Non-proliferative DR (NPDR)
•
early stage diabetic retinopathy
• Proliferative DR (PDR)
•
later stage diabetic retinopathy
http://www.aao.org/newsroom/release/20091030.cfm
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Non-Proliferative Diabetic Retinopathy
In NPDR, central vision is affected by the following:
• Hard exudates in the central retina (macula)
• Microaneurysms (small bulges in blood vessels of the
retina that can leak fluid)
• Retinal hemorrhages (tiny spots of blood that leak into
the retina)
• Macular ischemia (closing of small blood
vessels/capillaries)
• Macular edema (swelling/thickening of macula)
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Non-Proliferative Diabetic Retinopathy
Exudates and dot hemorrhages
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Non-Proliferative Diabetic Retinopathy
• The most common cause of decreased
vision in NDPR is macular edema.
• Macula edema occurs with weakening
of the walls of the retinal blood
vessels, leading to increased
permeability of the capillaries to
certain components of blood.
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Cross section of the retina
Ocular Coherence Tomography (OCT)
Normal retina
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Cross section of the retina
Ocular Coherence Tomography (OCT)
Macular edema
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Proliferative diabetic retinopathy
• Proliferative DR is the stage when abnormal
blood vessels begin to proliferate.
• The lack of oxygen in the retina causes new,
fragile, blood vessels to grow on the retina and
into the vitreous gel.
• These new blood vessels often bleed and
cause scarring.
• The scarring contracts the retina and causes
retinal detachment.
• The scarring can also cause a type of
glaucoma called neovascular glaucoma.
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Abnormal blood vessels
Neovascularization the optic disc
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Abnormal blood vessels
Neovascularization of the retina
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Abnormal blood vessels
Neovascularization and bleeding of retina
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Vitreous
Hemorrhage
Retinal
Detachment
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Abnormal blood vessels
Rubeosis iridis
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What are the risk factors for DR?
• level of glycemic control*
• duration of diabetes
• hypertension
• hyperlipidema
http://one.aao.org/CE/PracticeGuidelines/PPP_Content.aspx?cid=d0c853d3-219f-487b-a524-326ab3cecd9a
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Benefit of intensive glycemic control
Diabetes Control and Complications Trial (DCCT)
• The DCCT was a major clinical study conducted from
1983 to 1993 and involved 1,441 volunteers, ages 13
to 39, with type 1 diabetes at 29 medical centers in
the United States and Canada.
• Volunteers had to have had diabetes for at least 1
year but no longer than 15 years. They also were
required to have no, or only early signs of, diabetic
eye disease.
• The study compared the effects of standard control
of blood glucose versus intensive control on the
complications of diabetes.
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What was considered “intensive glycemic
control” in the DCCT?
• Intensive control involved keeping hemoglobin A1C levels as
close as possible to the normal value of 6 percent or less.
• The A1C blood test reflects a person's average blood glucose
over the last 2 to 3 months. Volunteers were randomly assigned
to each treatment group (standard vs. “intensive” control).
• Intensive control involved testing blood glucose levels four or
more times a day.
• Insulin was injected at least three times daily or administered
through an insulin pump.
• Patients were required to make monthly visits to a health care
team composed of a physician, nurse educator, dietitian, and
behavioral therapist.
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Cumulative incidence of DR in the DCCT
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How is diabetic retinopathy treated?
• In lower risk non-proliferative diabetic
retinopathy (NPDR), treatment includes strict
glycemic control and managing hypertension
and hyperlipidemia. In many cases, mild
NPDR can resolve completely without any
need for direct ocular treatment.
• In high risk non-proliferative (HR-NPDR), or
proliferative diabetic retinopathy (PDR),
treatment is recommended to prevent vision
loss.
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How is diabetic retinopathy treated?
The most common methods of treating diabetic
retinopathy are:
• laser (to seal leaking blood vessels and/or
decrease retinal oxygen demand)
• intravitreal injection (to decrease retinal
blood vessel leakage)*
• vitrectomy (surgical removal of blood and
scarring from the vitreous cavity)
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Retinal laser
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Laser photocoagulation
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Retinal laser
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Laser retinal photocoagulation
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Diabetic Retinopathy Study (DRS)
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Early Treatment of Diabetic Retinopathy Study (ETDRS)
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Intraocular injections
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Intraocular injections
Monoclonal antibodies
against VEG-F
• Bevacizumab (Avastin®,
Genentech/Roche)
• Ranibizumab (Lucentis®,
Genetech/Roche)
• Aflibercept (Eyelea®,
Regeneron)
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Surgical Vitrectomy
• Removal of blood and/or scarring from the vitreous
cavity
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Surgical Vitrectomy
• Performed in the operating room, this microsurgical
procedure involves removing the blood-filled vitreous
gel and replaces it with a clear solution.
• Vitrectomy often prevents
further bleeding by removing
the abnormal vessels.
• Vitrectomy can be combined
with laser.
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Eye Examinations in Diabetics
• American Diabetes Association
• Standards of Medical Care in Diabetes 2010
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Prevention
•
90 percent of diabetic eye disease can
be prevented simply by proper regular
examinations and strict glycemic
control.
http://www.aao.org/newsroom/release/20091030.cfm
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Recommended
Eye Examination
Diabetic Eye Disease
Key Points
Schedule
Diabetes Type
Recommended Time of Recommended FollowFirst Examination
up*
Type 1
3-5 years after
diagnosis
Yearly
Type 2
At time of diagnosis
Yearly
• Treatments
but work
Prior to exist
conception
No retinopathy to mildand early
in the firstis lost
moderate NPDR: every
best before
vision
trimester
3-12 months
Prior to pregnancy
(type 1 or type 2)
Severe NPDR or worse:
every 1-3 months.
*Abnormal findings may dictate more frequent follow-up examinations
http://one.aao.org/CE/PracticeGuidelines/PPP_Content.aspx?cid=d0c853d3-219f-487b-a524-326ab3cecd9a
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What happens during an eye exam?
• Your ophthalmologist will check your vision and eye pressure,
then dilate your pupils with eye drops.
• Once your pupils are dilated, your retina will be examined with a
microscope.
• The microscopes are either mounted on a table (slit lamp) or on a
headset (indirect ophthalmoscopy).
• If any abnormalities are suspected, then further testing will be
performed.
• Optical Coherence Tomography (OCT) takes digital cross sectional
images of the retina to find areas of swelling.
• Fluorescein angiography (FA) uses a special camera to take
photographs of the retina after yellow dye (fluorescein) is injected
into a vein in your arm.

The photographs of fluorescein dye traveling through the retinal
vessels show the location and severity of blood vessel leakage.
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Diabetic retinopathy is controllable
• The risk of vision loss can be significantly lowered by
maintaining strict control blood sugar.
• Treatment does not usually cure diabetic retinopathy,
but is effective in preventing further vision loss.
• Most people with diabetes retain normal eyesight and
total blindness is very uncommon if retinopathy is
treated.
• Regular visits to your ophthalmologist (Eye M.D.) will
help prevent vision loss.
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References
• Serrano I, Waxman E, Diabetic Retinopathy.
http://www.pitt.edu/~super7/46011-47001/46191.ppt. Accessed 6 April 2013.
• Preferred Practice Patterns, Diabetic retinopathy, America Academy of
Ophthalmology 2008.
http://one.aao.org/CE/PracticeGuidelines/PPP_Content.aspx?cid=d0c853d3219f-487b-a524-326ab3cecd9a
• Brett J. Rosenblatt and William E. Benson Diabetic Retinopathy Yanoff &
Duker: Ophthalmology, 3rd ed.
• Resnikoff S, Pascolini D, Etya'ale D, Kocur I, Pararajasegaram R, Pokharel
GP, Mariotti SP. Global data on visual impairment in the year 2002. Bull World
Health Organ. 2004 Nov;82(11):844-51. Epub 2004 Dec 14.
• Basic and Clinical Science Course, Section 12: Retina and Vitreous AAO,
2011-2012.
• Retina in systemic disease : a color manual of ophthalmoscopy / Homayoun
Tabandeh, Morton F. Goldberg 2009.
• The Effect of Intensive Diabetes Treatment On the Progression of Diabetic
Retinopathy In Insulin-Dependent Diabetes Mellitus, The Diabetes Control
and Complications Trial Research Group, Arch Ophthalmol. 1995; 113:36-51
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References
• http://www.ncbi.nlm.nih.gov/pubmed/19896746
• http://www.aao.org/eyecare/news/upload/Eye-Health-FactSheet.pdf
• http://www.who.int/bulletin/volumes/82/11/en/844.pdf
• http://jama.ama-assn.org/content/304/6/649.short?rss=1
•
http://www.aao.org/newsroom/release/20091030.cfm
•
http://www.diabetes.org/diabetes-basics/?loc=GlobalNavDB
•
http://www.ophed.com/group/2205
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Thank you!
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