Diabetic Retinopathy: Pathogenesis
and
clinical findings Authors:
Graeme Prosperi-Porta
Lucy
Yang
Reviewers:
Family history
ofТlDM
Genetics:
(DRЗ,
DR4,
DQ
non-asp genes)
Ethnicity:
White
youth,
African American,
Hispanic, Asian-Pacific
lslanders, and
American lndigenous
Туре
1 Diabetes
Mel
litus
Туре
2 Diabetes Mellitus
(ПDМ)
(see
Diabetes Mellitus,
(Т2DМ)
(see
Diabetes Mellitus,
Туре
/
for
pathogenesis)
Туре
II
for
pathogenesis)
..
I _
_..
Poor glycemic
cont
rol
....
__
_.!
•
Chronic high
Ыооd
sugar • inflammatory response
1' cytokines and
growth
factors
including vascular endothelial
growth
factor
(VEGF)
J
Vascular permeabllity
Retinal neovascularization
•
Vascular endothelial dysfunction:
basement membrane thickening,
vascular cell death, vascul
ar
occlusion
from
platel
et
aggregation
•
Retinal hypoxia
Polycystic Ovarian Syndrome
Family history
ofТ2DM
History
of
Gestational Diabetes
1' Body Mass lndex
1' Age
Ethnicity: lndigenous Americans,
African American, Hispanic
Stephanie Cote
Usama Malik
Мао
Ding
Johnathan Wong*
*
MD
at
time
о/
puЬ/ication
Diabetic Retinopathy (DR)
Outpouchings
of
the
weakened capillary walls
or
endothelial
buds
attempting
to
re
-vascularize
the
ischemic retina Micro-aneurysms
А
complication
of
diabetes
due
to
chronic hyperglycemia
resulting in abnormal permeabllity and ischemia
of
retinal vessels Weakened
Ыood
-
retina
l
barrier
(BRB)
a
ll
ows
for
rupture
into
the
deeper retinal layers
...,.
Dot/Ыot
hemorrhages
Pericyte death,
breakdown
of
endothelial
tight
junctions &
basement membrane
thickening damages
Ыood-retinal
barrier
Damaged
Ыood
retinal
border
leaks
fluid
into
the
retinal
tissues
~
Macular edema
(swelling
of
macula)
Legend:
Pa
thophysiology
1 •
Mild
Non-proliferative
DR
+
Moderate
Non-proliferative DR
~
Severe Non-proliferative DR
+
Proliferatlve
DR
Presence
of
neovascularization
!
Localized
ret
inal ischemia causes
upregulation
of
vascular
endothelial
growth
factor causing
fine, irregular & easily
friaЫe
neovascularization
in
the
disc,
macula,
and/or
retina
Lipid deposits
with
sharp margins due
to
lipoproteins &
othe
r
proteins leaking through
the
damaged
Ыood-retinal
barrier
Hard exudates (yellow
opaque solids on retina)
Nerve
fiber
layer infarcts
from
occ
lu
sions
of
the
precapillary
arterio
les
Cotton-wool spots (cloudy
....., translucent patches on retina)
Retinal hemorrhages occur in
the
more superficial nerve layer
......
Focal areas
of
saccular venous bulges due
to
significant retinal
....
ischemia & endothelial wall weakening and damage
Neovascularization
-+
(fine loop networks
of
new
Ыооd
vessels)
Neovascular membranes in vitreous gel
Flame hemorrhages
(multip
le opaque red patches)
Venous beading (veins
with
areas
of
narrowing forming
bead-like segments)
Traction retinal
detachment
<
form
vitreoretinal adhesions and contract
Fragile vessels extending
into
the vitreous
....
humor
Bleeding
into
the
vitreous humor
Mechanism Sign/Symptom/Lab Finding Complications
PuЬl
i
shed
June 28, 2017, updated
Мау
18, 2023 on
www.
thecalgaryguide.com
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