retina 1 anatomy and diabetic retinopathy d r.k.n.jha-26.05.16
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Retina 1Diabetic RetinopathyProf K N Jha, MSEmail: [email protected]
Learning Aim•Retina: Retinal topography, and Histology
•Clinical features of diabetic retinopathy
•Diabetic retinopathy and visual impairment
•Treatment of diabetic retinopathy
•Prevention of visual impairment and blindness due to diabetic retinopathy.
Development of Retina
RPE
Neurosensory retina
Subretinal space
Normal Fundus: Retinal Topography
Retina: Schematic Diagram
Diabetic RetinopathyGlobally , diabetic retinopathy accounts for about 1 % of blindness. In India, diabetic retinopathy accounts for about 0.1 % of blindness.
Diabetic Retinopathy• The best predictor of diabetic retinopathy is the
duration of the disease.
• Type I diabetes The first 5 years of type 1
diabetes has a very low risk of retinopathy. All
patients develop retinopathy in 15 years.
• Type II diabetes: Risk of retinopathy increases
with duration of diabetes , hypertension and
smoking, and renal pathology.
Diabetic RetinopathyRisk factors:
• Diabetic age and age of the patient• Glycemic control• Hypertension• Poor renal status• Smoking• Pregnancy, obesity, hyperlipidemia,
anemia
Pathogenesis DR is predominantly a microangiopathy
resulting from hyperglycemia.
Vascular Endothelial Growth Factor (VEGF)
appears to be of particular importance in
development of proliferative changes .
Pathogenesis Capillaropathy: loss of pericytes,
thickening of basement membrane , and
proliferation of endothelium.
Haematological changes
Microvascular occlusion leading to
hypoxia
Pathogenesis
Consequences of chronic leakage
Consequences of retinal ischaemia
Types
● Non-Proliferative Diabetic Retinopathy(NPDR)/background diabetic
retinopathy ( BDR)
● Proliferative Diabetic Retinopathy(PDR)
Clinical Features•Asymptomatic in the beginning
•Symptoms depend upon the retinal changes.
•Painless diminution of vision
•Dilated fundus examination shows typical
features.
Fundus FindingsFeatures of NPDR
● Microaneurysms
● Dot and blot hemorrhage
● Retinal edema and exudates
● Dilatation and beading of retinal veins
● Intra retinal Microvascular Abnormalities (IRMA)
Features of PDR
Neovascularization disc (NVD)
Neovascularization elsewhere(NVE)
In addition to other changes of NPDR
Early NPDR
Macular Edema
Proliferative Diabetic Retinopathy
Extra retinal fibrovascular proliferation extends beyond the internal limiting membrane (ILM).
• It’s the commonest cause of spontaneous vitreous hemorrhage in adults.
• About 2/3rd of Type I diabetics are likely to develop PDR over 3 decades.
Proliferative Diabetic Retinopathy
Proliferative Diabetic Retinopathy
Summary of Fundus Findings• Microaneurysms ,hemorrhage , hard
exudates
•Capillary non-perfusion , Intra Retinal
Microvascular Abnormalities (IRMA)
•Neovascularisation: NVD,NVE
•Vitreous hemorrhage , retinal detachment
Cause of Visual Impairment NPDR
● Macular edema (capillary leakage)
● Macular ischemia (capillary occlusion)
● Sequelae from ischemia related neovascularization
PDR
• Vitreous hemorrhage,
retinal detachment.
• Diabetic macular edema
• Ischemic macular changes
Diagnosis of Diabetic RetinopathyClinical Exam
•Direct ophthalmoscopy under mydriasis
•Slit lamp biomicroscopy using +90 D lens
•Fluorescein angiography
Screening Schedule•: Normal fundus , rare microaneurysms:
Annual review
•Mild NPDR: Every 9 months
•Moderate NPDR: Every 6 months
•Severe NPDR, CSME: Every 2-4 months
•PDR: Every 2-4 months
Treatment of Diabetic Macular Edema (DME)
Laser Photocoagulation• Grid laser :For diffuse retinal thickening outside FAZ.• Focal laser : microaneurysms in centre of hard
exudates.
Medical Treatment:
-intravitreal injection: Triamcinolome acetonide / anti-
VEGF
- posterior sub-tenon injection of corticosteroid
Surgery: Parsplana vitrectomy
Treatment of PDR
•Panretinal Laser photocoagulation (PRP) : For NVD And NVE
•Vitreoretinal surgery and PRP : - Severe persistent vitreous hemorrhage
- Dense, persistent premacular hemorrhage - Progressive proliferation despite laser
therapy - Retinal detachment involving macula
• Spot size (200-500 m)
• Follow-up 4 to 8 weeks
• Area covered by complete PRP• Initial treatment is 1200 + burns
Laser Panretinal Photocoagulation(PRP)
Prevention Visual Loss•Patient education and good diabetic control
•Control of hypertension, hyperlipidemia, renal
disease, anaemia, and avoidance of smoking
•Periodic dilated fundus examination
•Early treatment of macular edema and PDR
•Treatment of complications
Points to remember•Pathogenesis, types, clinical features and
diagnosis of diabetic retinopathy
•Cause of visual impairment in diabetic retinopathy
•Prevention of visual loss due to diabetic retinopathy
•Schedule of examination in diabetics
Frequently-Asked Questions
•Pathogenesis of diabetic retinopathy
•Fundus findings in diabetic retinopathy
• Diagnosis of diabetic retinopathy
•Patient education for prevention of
blindness from diabetes.