Transcript Diabetic Retinopathy

Diabetic Retinopathy
Steven Sanislo, M.D.
Assistant Professor
Stanford University Department of
Ophthalmology
Diabetic Retinopathy
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Diabetic retinopathy is a leading cause of
new cases of blindness in people aged 20
to 74 years in the USA
Many of the complications of diabetic
retinopathy can be prevented or delayed
by blood glucose control and timely
intervention.
Ocular Anatomy
Retinal Anatomy
Retinal Histology
Sclera
Outer
Plexiform layer
Choroid
Bipolar cells
RPE
Photoreceptor
outer segments
Inner
plexiform layer
Ganglion cells
Photoreceptor
inner segment
Nerve fiber
layer
Retinal Diagnostic Tests
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Fundus Photography
Fluorescein Angiography (FA)
Optical Coherence Tomography (OCT)
Ocular Ultrasonography
Electroretinography (ERG)
Fundus Photos and FA
Fundus Photography
Normal FA
Optical Coherence
Tomography (OCT)
Normal OCT
B-scan Ultrasound
Normal Ultrasound
Pathogenesis of DR
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Prolonged hyperglycemia is the major
etiologic agent in all of the microvascular
complications of diabetes, including
diabetic retinopathy.
The cellular mechanisms through which
hyperglycemia acts currently remain
unclear
Pathogenesis of DR
Mechanisms that have been proposed are:
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1. hyperglycemia may alter the expression of one or
more genes, leading to increased (or decreased)
amounts of certain gene products that can alter cellular
functions.
2. Glycosylated proteins can undergo a series of
reactions, leading to considerable alteration of proteins.
3. Chronic hyperglycemia may produce oxidative stress
in cells, leading to the formation of an excess of "toxic
end products of oxidation" including peroxides,
superoxides, nitric oxide, and oxygen free radicals.
VEGF and DR
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Vascular Endothelial Growth Factor
Promotes vascular growth and
permeability
Elevated levels of circulating VEGF in
conditions with retinal ischemia
Anatomic Changes
Microanerysms
 Damage to
endothelial cells leads
to dilated capillaries
and venules
 These altered vessels
allow serum and
blood to leak into the
retina
NPDR
NPDR FA
NPDR OCT
Retinal Ischemia
PDR
PDR
PDR FA
Vitreous Hemorrhage (VH)
VH ultrasound
TRD ultrasound
Epiretinal Membrane
PDR Retinal Detachment
Iris Neovascularization
Mechanisms of Vision Loss
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Retinal ischemia
Macular edema
Vitreous hemorrhage
Epiretinal membrane formation
Retinal detachment
Neovascular glaucoma
Prevention
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Prospective controlled interventional
studies have shown that strict control of
blood glucose and blood pressure
significantly reduces and delays the onset
and severity of diabetic retinopathy.
Screening
Type 1 diabetics:
First screen 5 years after onset, then
annually.
Type 2 diabetics:
First screen upon diagnosis and then
annually.
Treatment
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NPDR without macular edema 
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Observe
Macular edema 
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1. Focal/Grid laser photocoagulation
2. Vitrectomy with membrane peeling
3. Intraocular Steroid*
4. Intraocular VEGF inhibitor*
* Off-label use, contraversial
DME laser treatment
DME laser treatment
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Treatment
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Vitreous Hemorrhage 
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1. Pan-retinal photocoagulation
2. Vitrectomy with laser photocoagulation
3. Intraocular VEGF inhibitor*
Traction Retinal Detachment 
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1. Observation if not involving the macula
2. Vitrectomy with membrane dissection
* Off-label use, contraversial
Pan-retinal Photocoagulation
Vitrectomy
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http://www.youtube.com/watch?v=iOwpEa4KB5c