Diabetic retinopathy

DIABETIC RETINOPATHY

Dr. Christina Samuel

DEFINITION

• DIABETIC RETINOPATHY IS A PROGRESSIVE MICRO ANGIO PATHY WITH CONSEQUENT BREAK DOWN OF BLOOD RETINAL BARRIER RESULTING IN A VARIETY OF FUNDUS PICTURE FINALLY LEADING TO BLINDNESS

DIABETIC RETINOPATHY

RISK FACTORS/PROGNOSTIC FACTOR

DURATION OF DM- type 1 4-5yrs no DR type 2 11-13yrs 23% NPDR 5-10yrs 25%-30% 3% PDR 10-15yrs 75%-95% 16yrs 60% NPDR 20-25yrs PDR in 18%-40• TYPE OF DM • AGE • BLOOD GLUCOSE LEVELS • HT • NEPHROPATHY • SERUM LIPIDS • ANEMIA• PUBERTY,PREGNANCY,BMI

LOCAL PROTECTIVE FACTORS

• MYOPIA

• CHORIO RETINAL SCARRING

• GLAUCOMA

• OPTIC ATROPHY

• RP

PATHOGENESIS• MICROANGIOPATHY AFFECTING PRE CAPILLARIES

ARTERIOLES,CAPILLARIES & VENULES.• FEATURES

MICROVASCULAR MICROVASCULAR OCCLUSION LEAKAGE RETINAL ISCHEMIA IRMA NV H’GES EDEMA EXUDATES hematological loss of pericytes vascular abn breakdown of BRB

HEMATOLOGICALABNORMALITIESHEMATOLOGICALABNORMALITIES• ABNORMALITIES OF PLATELET ABNORMALITIES OF PLATELET FUNCTIONFUNCTION• DEFECTIVE FIBRINOLYTIC DEFECTIVE FIBRINOLYTIC SYSTEMSYSTEM• HYPERVISCOSITY AND ABNORMALHYPERVISCOSITY AND ABNORMAL RBC AGGREGATION RBC AGGREGATION • ABNORMAL SERUM LIPIDSABNORMAL SERUM LIPIDS

MICROVASCULAR ABNORMALITIESMICROVASCULAR ABNORMALITIES• BASEMENT MEMBRANE THICKENING BASEMENT MEMBRANE THICKENING • earliest changeearliest change increased BM proteinsincreased BM proteins• LOSS OF PERICYTES 1:1 ratio-normalLOSS OF PERICYTES 1:1 ratio-normal loss of BRBloss of BRB autoregulation autoregulation new vesselsnew vessels

PATHOGENESIS

•OTHER VASCULAR

ABNORMALITIES

–COAGULATION

–PERMEABILITY

–CONTRACTILITY & FLOW

–CELLULAR REGENERATION

Normally- TGF-B release by endo cells

inhibition of proliferation

In DR- loss of pericytes

prevents expression of TGF-B

endothelial cell proliferation

microaneurysms

ANGIOGENIC FACTORS FGF,TGF-B,PDGF,IGF-1 & 2,VEGF• FGF-basic• IGF-1 &2• VEGF-produced by retina -induced by hypoxia -pro angiogenic -induces permeability -diffusible thru out eye

PATHOLOGICAL LESIONS MICRO ANUERYSMS

• Signs-tiny, round dots

• site-inner nuclear layer. Venous end of capillaries

• size-12-100mic, >30 mic

• course-hyalinization, occlusion, months -yrs

• Importance-

• RETINAL HEMORRHAGES Intra retinal “Dot –blot” Site-inner nuclear layer venous end of capillary

“flame shaped” site-NFL superficial pre-capill arterioles

HARD EXUDATES• Signs-waxy, yellow with distinct margins • Site-outer plexiform layer• Composition-lipoproteins, lipid laden macrophages• Due to abnormal cap

& microanuerysms• Circinate pattern

SOFT EXUDATES• cotton wool spots• signs-whitish, fluffy,obscure blood vessels• composition-axoplasmic stasis• course- in wks to mths• importance –focal infarcts

8 or more-PDR in 6-18mths

IRMA• Shunts from arterioles to venules• close to areas of capillary closure• signs-fine red lines, focal areas of flat new vessels• distinguishing feature-intra retinal , do not cross major vessels, absence of leak RETINAL EDEMA• site-all layers• signs-retinal thickening, transparency lost cystoid appearance

CAPILLARY ABNORMALITIES • occlusion –focal, perifoveal, regional• dilatation• microaneurysm• abnormal permeability ARTERIOLAR ABNORMALITIES• obstruction• sheathing VENOUS ABNORMALITIES• general dilatation• beading & sausaging• venous kinks & loops• reduplication• CRVO• BRVO

DIABETIC MACULOPATHY

MACULAR EDEMA- S/L examination ( Bimicroscopy), Absence of foveal reflex Cystoid appearance

TYPES Focal Diffuse Ischemic Mixed Detachment of macula

Diabetic maculopathy FOCAL- well circumscribed retinal thickening

Rings of perifoveal exudates

around discrete foci of capillary abnormalities

DIFFUSE- thru out post pole

diffuse capillary abn.

ISCHEMIC-VA decreased but normal appearance

CWS +

focal cap drop outs

enlargement of FAZ

occl. of art in the macula

MIXED

MACULAR DETACHMENT

ABBREVIATIONS

• CWS-COTTON WOOL SPOTS

• VA-VISUAL ACUITY

• FAZ-FOVEAL AVASCULAR ZONE

• MA-MICRO ANEURYSM

MODERN ETDRS CLASSIFICATIONNPDR ( Non-Proliferative Diab Retinopathy)• MILD- at least 1 micro aneurysms Hard exudates Intra retinal h’ges Macular edema FAZ abnormalities

• MODERATE-Venous beading CWS IRMA Intraretinal h’ges

• SEVERE- Intraretinal h’ges in 4 quadrants Venous beading in 2 quadrants IRMA in 1 quadrant

• VERY SEVERE- Any 2 of the above

MILD NPDR:

•ATLEAST ONE Ma /HGE

ANY QUADRANT

MODERATE NPDR:

MODERATE AMT OF Ma/HGES

WITH HARD /SOFT EXUDATES

SEVERE NPDR:

ATLEAST ONE OF THE FOLLOWING—

• HGES/Ma --- ALL 4 QUADRANTS

• VENOUS BEADING IN TWO

QUADRANTS• INTRA RETINAL MICROVASCULAR

ABNORMALITIES- ONE QUADRANT

VERY SEVERE NPDR:

TWO OF THE ABOVE CRITERIA

PROLIFERATIVE Diab Retinopathyhy-PDR

• EARLY-

NVD ( neovascularisation of the disc)

NVE ( neovascularisation elsewhere)

Vitreous/Preretinal h’ge &NVE >1/2DD

• HIGH RISK PDR-

NVD >1/4-1/3 DD

NVD & vitreous/preretinal h’ge

NVE>1/2DD & vitreous/preretinal h’ge

• ADVANCED PDR –

Tractional RD inv macula

Vitreous h’ge obscuring grade

PROLIFERATIVE DR:

NEW VESSELS ON THE DISC ( NVD )

NEW VESSELS ELSEWHERE ( NVE ):

ADVANCED PROLIFERATIVE

DR

FIBROVASCULAR BANDS

PRE RETINAL HGE

CLINICALLY SIGNIFICANT MACULAR EDEMA

THREE CRITERIA:criteria 1

• RETINAL THICKENING WITHIN 500 MICRONS

FROM THE FOVEA

CLINICALLY SIGNIFICANT MACULAR EDEMA

criteria-2HARD EXUDATES

WITHIN 500 MICRONS

OF FOVEA WITH

ADJACENT RETINAL

THICKENING

CLINICALLY SIGNIFICANT MACULAR EDEMA

Criteria-3

•RETINAL THICKENING

OF > 1 D.D. EVEN IF PARTLY

WITHIN 500 MICRONS OF FOVEA