6. What is Diabetic retinopathy?
Specific vascular complication
of diabetes mellitus
Microangiopathy
Neuropathy
Nephropathy
Remains a leading cause of
new blindness
7. Diabetic Retinopathy
Duration of diabetes,
after 20 years:have some degree of retinopathy
nearly all patients with type 1 diabetes mellitus
more than 60% of patients with type 2 diabetes mellitus
Other risk factors: pregnancy, hypertension,
renal disease, obesity, hyperlipidaemia,
smoking, anaemia
8. Pathogenesis
Weak capillary wall →
saccular outpouching of wall
(microaneurysm)-may leak
or thrombosed
Breakdown of inner BRB
Leakage: capillary changesOcclusion
1. Capillary changes
2. Haematological
changes
31. When to screen for DR
All NIDDM at the time of diagnosis
(once a year)
IDDM after at least 5 years of diagnosis
Diabetic women
planning for pregnancy
need to have complete eye examination
before conception
Once becomes pregnant
should be examined for retinopathy early in the
first trimester
35. HYPERTENSION AND EYE
The eye is the only place in the body
where the vessels can be directly
observed
Patients with hypertensive retinopathy
are usually asymptomatic
36. Hypertensive changes in the eye
Acute hypertension (suddden rise of BP)
Grade III and IV hypertensive retinopathy
Choroidopathy
Optic neuropathy
Chronic hypertension
Arterial changes
37. Pathophysiology
Arteriolar narrowing due to
vasoconstriction and arteriolosclerosis
(increase in elastic tissue and
musculature)
Focal closure of retinal vasculature lead
to microinfarcts (cotton wool spots) and
haemorrhages
Leakage lead to oedema and exudates
Disc oedema develops in advanced
stage)
38. Classification
(modified Keith-Wagener-Barker / Scheie)
Grade Haemorr-
hage
Exudate Disc
swelling
AV ratio Light
reflex
AV
crossing
changes
Normal none none none 3:4 Fine
yellow
None
Grade 1 none none none 1:2 Broad
yellow
Mild vein
depression
Grade 2 none none none 1:3 Copper
wiring
A-V
nipping
Grade 3
+ + none 1:4 Silver
wiring
Right angle
Deviation /
Distal
dilatation
Grade 4
+ + + fine
cords
as stage 3 as stage 3
42. Keith, Wagener, and Barker 1939
The changes seen in groups I and II are
typically chronic
groups III and IV are seen with more
acute rises in blood pressure.
Retinal haemorrhages and hard exudates,
cotton wool spots, optic disc swelling
43. Is there a need to refer all
hypertensive patients to
ophthalmologist? No, if there is no visual impairment
We do not monitor the fundus of HPT
patients
If BP is high: refer physician
44. Management HT retinopathy
Referral to physicians for control of the blood
pressure: urgency depends on the stage
Stage 1 n 2: BP monitoring if on treatment
Stage 3 n 4: urgent referral
45. Retinal diseases - outline
Diabetes mellitus
Hypertension
Other retinal vascular problem: CRVO/CRAO
Age related macular degeneration (AMD)
Retinal Detachment
61. Detection: The Amsler grid
Amsler grids can
facilitate early detection
Signs suggestive of CNV
include:
Distortion
Blurring
Darkening or discoloration
of the grid lines
Inability to fix on the
central dot
64. Occlusion of CNV
Reactive oxygen
products
Occlusion of abnormal
vessels
Light-activation of Visudyne
Endothelial cell damage
and thrombus formation
65. Retinal diseases - outline
Diabetes mellitus
Hypertension
Other retinal vascular problem: CRVO/CRAO
Age related macular degeneration (AMD)
Retinal Detachment
66. Retinal detachment
Separation of the neurosensory
layer from the retinal pigment
epithelium (RPE)
1. Rhegmatogenous (RRD)
Retinal tear / hole
Risk factors – high myopia, intraocular
surgery, trauma
2. Tractional (TRD)
Proliferative diabetic retinopathy (PDR)
3. Exudative
Malignant HPT, tumour, uveitis - VKH