Topic assignment : medical ophthalmology Diabetic retinopathy Dr.Vijay

Contents Diabetes Definition Risk factors Pathogenesis Classification : proliferative / non-proliferative Sign & symptoms DDx & other ocular complication of DM Treatment & follow up Screening for DR Apply with case study

Diabetes mellitus Group of common metabolic disorders Caused by a complex interaction of genetics and environmental factors Lack of insulin  hyperglycemia Diagnostic criteria : Fasting plasma glucose > 126 mg/dl Type 1 DM – Insulin-dependent diabetes (IDDM) Results from pancreatic beta-cell destruction, usually leading to absolute or near total insulin deficiency Type 2 DM - Non-insulin-dependent diabetes (NIDDM) Variable degrees of insulin resistance and impaired insulin secretion, resulting in hyperglycemia and other metabolic derangements due to insufficient insulin action.

Diabetes mellitus Long-standing hyperglycemia leads to multiple organ damage Macrovascular complications Stroke Heart disease and hypertension Peripheral vascular disease Foot problems Microvascular complications Diabetic eye disease : retinopathy and cataracts Renal disease Neuropathy

Diabetic retinopathy The most severe of ocular complications of diabetes Caused by damage to blood vessels of the retina, leads to retinal damage Microvascular complication of longstanding diabetes mellitus [1] Most prevalence cause of legal blindness between the ages of 20 and 65 years Common in DM type 1 > type 2

Risk factors Duration of diabetes Poor metabolic control Pregnancy Most important Pt diagnosed before age 30 yr 50% DR after 10 yrs 90% DR after 30 yrs Poor metabolic control Less important, but relevant to development and progression of DR  HbA1c ass. with  risk Pregnancy Ass with rapid progression of DR Predicating factors : poor pre-pregnancy control of DM, too rapid control during the early stages of pregnancy, pre-eclampsia and fluid imbalance

Pathogenesis Microvascular occlusion Microvascular leakage

Microvascular leakage Degeneration and loss of pericytes Capillary wall weakening Plasma leakage microaneurysm Retinal edema Hard exudate (Circinate pattern) Intraretinal hemorrhage

Non-proliferative diabetic retinopathy Right eye: Micro aneurysm, few flame-shaped and dot-blot hemorrhages and hard exudate [with hard exudate in macula area] , ไม่พบ neovascularization เข้าได้กับ moderate non proliferative diabetic retinopathy Left eye: Micro aneurysm, numerous flame-shaped and dot-blot hemorrhage [more than 20 dots in 4 quadrant], hard exudate [with hard exudate in macula area] ไม่พบ neovascularization เข้าได้กับ severe non proliferative diabetic retinopathy

Microvascular occlusion Endothelial cell damage and proliferation Capillary basement membrane thickening Decreased capillary blood flow and perfusion Increased plasma viscosity Deformation of RBC Increased platelets stickiness Retinal hypoxia VEGF A-V shunt IRMA* Neovascularization and fibrovascular proliferation Rubeosis iridis Proliferative retinopathy *intraretinal microvascular abnormalities

Vitreous hemorrhage Tractional retinal detachment

Classification Non-proliferative diabetic retinopathy (NPDR) Proliferative diabetic retinopathy (PDR)

Non-proliferative diabetic retinopathy Mild NPDR Moderate NPDR Severe NPDR

Sign NPDR Microaneurysm Retinal hemorrhage Hard exudate “Dot or Blot” Spot “Flame or Splinter shape” hemorrhage Hard exudate Cotton wool Spot Venous beading Intra-retinal microvascular abnormalities (IRMA)

Mild NPDR Microaneurysm

Moderate NPDR More microaneurysms Scattered hard exudates Cotton-wool spots

Severe NPDR Very severe NPDR  more than 1 of above 4-2-1 rule 4 quadrants of severe retinal hemorrhages 2 quadrants of venous beading 1 quadrant of IRMA Very severe NPDR  more than 1 of above

Microaneurysm Localized saccular outpouchings of capillary wall  red dots Focal dilatation of capillary wall where pericytes are absent Fusion of 2 arms of capillary loop Usually seen in relation to areas of capillary non-perfusion at the posterior pole esp temporal to fovea The earliest signs of DR

Microaneurysm

Retinal Hemorrhage Capillary or microaneurysm is weakened  rupture  intraretinal hemorrhages Dot & blot hemorrhages Deep hemorrhage - inner nuclear layer or outer plexiform layer Usually round or oval Dot hemorrhages - bright red dots (same size as large microaneurysms) Blot hemorrhages - larger lesions Flame-shape or splinter hemorrhages More superficial - in nerve fiber layer Absorbed slowly after several weeks Indistinguishable from hemorrhage in hypertensive retinopathy May have co-existence of systemic hypertension  BP must be checked

Hemorrhage

Hard exudate Intra-retinal lipid exudates Yellow deposits of lipid and protein within the retina Accumulations of lipids leak from surrounding capillaries and microaneuryisms May form a circinate pattern Hyperlipidemia may correlate with the development of hard exudates

Cotton Wool Spot White fluffy lesions in nerve fiber layer Result from occlusion of retinal pre-capillary arterioles supplying the nerve fibre layer with concomitant swelling of local nerve fibre axons Also called "soft exudates" or "nerve fiber layer infarctions" Fluorescein angiography shows no capillary perfusion in the area of the soft exudate Very common in DR, esp if pt with HT

Venous beading Dilatation and beading of retinal vein Appearance resembling sausage-shaped dilatation of the retinal veins Sign of severe NPDR

Intra-retinal microvascular abnormalities (IRMA) Abnormal dilated retinal capillaries or may represent intraretinal neovacularization which has not breached the internal limiting membrane of the retina Indicate severe NPDR  rapidly progress to PDR

Venous beading

Proliferative diabetic retinopathy 5% of DM pt. Finding Neovascularization : NVD, NVE Vitreous changes Advanced diabetic eye disease Final stage of Uncontrolled PRD Glaucoma (neovascularization) Blindness from persistent vitreous hemorrhage, tractional RD, opaque membrane formation, 32

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Neovascularization of disc 34

Neovascularization of elsewhere Fluorescein dye leakage is seen in neovascularized area

(neovascularisation of the iris) Rubeosis iridis (neovascularisation of the iris) Neovascular glaucoma

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Vitreous changes 40

Tractional retinal detachment Vitreous hemorrhage

NVE Venous beading IRMA

New vessels of the disc (advanced)

Signs & symptoms of DR Blurred or distorted vision or difficulty reading Floaters Partial or total loss of vision a shadow or veil across patient’s visual field Eye pain 44

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Hypertensive retinopathy

Medical therapy Prevention Treat underlying conditions Control blood sugar – HbA1c < 7 Control blood pressure – SBP < 130 mmHg Control lipid profile – TG, LDL Correct anemia Control diabetic nephropathy Pregnancy makes DR worsen

Laser Panretinal photocoagulation (PRP) High-risk PDR (3/4) Vitreous or preretinal hemorrhage New vessels New vessels on optic disc or within 1,500 microns from optic disc rim Large new vessels Iris or angle neovascularization CSME

Photocoagulation Focal or Grid Panretinal (PRP) CSME in both NPDR and PDR Panretinal (PRP) PDR

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