Ocular Abnormality- Diabetes Ii

Front 1

What is Diabetic Retinopathy (DR)?

Back 1

Characteristic group of retinal lesions found in individuals with Diabetes Mellitus (DM)

Front 2

What percentage of cases of blindness worldwide does DR account for?

Back 2

4.8%

Front 3

What if DR leading cause of in the UK?

Back 3

Leading cause of PREVENTABLE sight loss in UK working age population

Front 4

What increases prevalence of DR?

Back 4

• Px age (variable evidence)

• Duration of diabetes

• Ethnicity (Asian/African-Carribbean, >T2)

• Anaemia

Front 5

What increases prevalence and progression of DR?

Back 5

• Poor glucose control

• Poorly controlled BP & Hyper-lipidaemia

• Smoking

• Obesity (DR earlier onset)

• Pregnancy

• Nephropathy

Front 6

What supplies the inner 6 layers of the retina (ILM- OPL)?

Back 6

Central retinal artery

Front 7

What supplies the outer 4 layers of the retina?

Back 7

Choroidal vessels

Front 8

What are the 3 structural changes to vessels caused by hyperglycemia?

Back 8

• Basement membrane thickening

• Selective pericyte loss

• Endothelial cell changes

Front 9

What are the physical consequences from damage to the vessels?

Back 9

• Micro-vascular leakage

• Micro-vascular occlusion

Front 10

What is Micro-vascular leakage?

Back 10

• Disruption to inner blood retinal barrier

• Increased vascular permeability leads to loss of vascular contents = leakage

Front 11

What does Micro-vascular leakage result in?

Back 11

• Leakage of plasma

• Release of lipids, lipo-proteins & blood

• Retinal oedema (diffuse/localised)

Front 12

What is Micro-vascular occlusion?

Back 12

• Vessel closure (》Ischaemia)

• Thickened basement membrane & Endothelial cell loss

• Changes in red blood cells-affects O2 transport

• Increased ‘stickiness ’& aggregation of platelets

Front 13

What does Micro-vascular occlusion lead to?

Back 13

• Formation of abnormal arterio-veneous shunts within the retina

• Formation of ‘new’ vessels

Front 14

What is a microaneurysm?

Back 14

• First clinically detectable retinopathy feature

• Focal dilatation of capillary wall (due to pericyte loss)

• Small, round, red ‘dots’

Front 15

What layer of the retina is a microaneurysm usually seen?

Back 15

• Inner nuclear layer of retina

• Commonly temporal to macula

Front 16

What are haemorrhages?

Back 16

'dots and blots'

• Ruptured capillary or micro-aneurysm

• Round or oval

• ‘dot’- Same size as microaneurysms

• ‘blot’- larger

Front 17

What layer of tbe retina are dots and blota found?

Back 17

Middle retinal layer

Front 18

What is this?

Back 18

Flame shaped/Splinter haemorrhage

• Follow course of retinal nerve fibre layer

• Feathered appearance

Front 19

Where in the retinal layer would a flame haemorrhage be seen?

Back 19

More superficial

Front 20

What are hard exudates?

Back 20

• Intra-retinal lipid exudates

• Lipid leakage 》 capillaries & micro-aneurysms

Front 21

What layers of the retina is hard exudates found?

Back 21

Between inner plexiform & inner nuclear layer

Front 22

DR features location

Back 22

Front 23

What are cotton wool spots?

Back 23

• “Soft exudates”

• White ‘fluffy’ lesions

• Interrupted axoplasmic flow

• Build-up of transported axonal matter

Front 24

What layer of the retina are cotton wool spots found?

Back 24

Pre-capillary arteriole occlusion in nerve fibre layer (> superficial)

Front 25

What can cotton wool spots be a sign of?

Back 25

Capillary non-perfusion- Ischaemia

Front 26

What is oedema?

Back 26

• Increased retinal capillary permeability

• Appears as retinal thickening

Front 27

What layers of the retina would you find oedema?

Back 27

• Starts in outer plexiform & inner nuclear layers

• Progresses to nerve fibre layer (full thickness)

• Obscures underlying RPE & choroid

Front 28

What should you check for if you see oedema?

Back 28

VA and Amsler chart

Front 29

What does IRMA stand for?

Back 29

Intra-retinal micro-vascular abnormalities

Front 30

What is IRMA?

Back 30

• Retinal ischaemia

• Formation of new FLAT capillary networks

• Abnormal irregular patches of branching vessels

• Do not cross over major retinal vessels

Front 31

What other vascular changes can occur with VEINS in DR?

Back 31

• Dilation

• Tortuosity

• Beading (focal dilation & narrowing)

• Looping (may arise from focal vitreous traction)

• Segmentation ‘sausage like’ (appears as exaggerated beading)

• ALL indicate retinal ischaemia

Front 32

What other vascular changes can occur with ARTERIES in DR?

Back 32

• Narrowing (AV ratio?)

• Possible obliteration (will resemble branchretinal artery occlusion)

• Link with HTN

Front 33

What is the chain of events Ischaemia promotes?

Back 33

• Production of Vasc. Endothelial Growth Factor

• leads to Abnormal New vessels (neo-vascularisation)

• Originate from veneous circulation

• Between internal limiting membrane & posterior vitreous

• Present @ disc (NVD) or elsewhere (NVE)

• Weak, leaky structure (fenestrated endothelial cell junctions)》 highly prone to leakage

Front 34

What is this?

Back 34

New vessels at the disc

• Initial finebvascular strands

• May appear linear or compact mass of vessels

• Tend to follow temporal arcades

• Adhere to posterior vitreous with continued growth

Front 35

What else can new vessel growth lead to?

Back 35

• May spread along posterior vitreous

• NV maturation

• Tissue adheres to posterior vitreous

• Stimulates vitreous detachment (usually incomplete, if complete-NV’s may regress)

• Traction and rupture of NV’s (haemorrhage)

Front 36

What can the leaky vessel heamorrhage lead to?

Back 36

• May penetrate vitreous gel

• Dark red

• Highly symptomatic

• Loss of VA

• Sudden floaters

• Can lead to retinal detachment

Front 37

What is this?

Back 37

Response to ischaemia

• Small fine vessels on anterior iris

• Initially at pupil border

Front 38

What can new vessels at the anterior iris lead to?

Back 38

• Progress to block.a.c

• ‘Neovascular’ glaucoma

• Pain, decreass in VA

• Increase IOP, Cloudy cornea

• Hyphaema

Front 39

What are the 3 types of diabetic maculopathy?

Back 39

• Focal

• Diffuse

• Ischaemic

Front 40

What is focal maculopathy?

Back 40

• Micro-aneurysms

• Surrounding hard exudate (complete or incomplete ring)

• Circumscribed retinal thickening

• Focal oedema

• Often good VA prognosis

Front 41

What is diffuse maculopathy?

Back 41

• Diffuse macula oedema

• Obscuration of RPE & choroid

• Leakage from vessels & micro-aneurysms

• Increased fluid》may show cystoid macula appearance

Front 42

What is Ischaemic maculopathy?

Back 42

• Capillary closure

• Features may vary (mild-severe)

• Large blots haems

• Multiple CWS

• Veneous changes

• IRMA

• Variable macula oedema

• Poor VA

Front 43

Classification

Back 43

Front 44

Who gets seen at the NationalDiabetic Eye Screening Programme: NHS England

Back 44

All Diabetics age 12+ annual screening available

Results to GP: within 6/52

Front 45

What are the screening outcomes?

Back 45

R0/MO, R1/MO (monoc/binoc): 12/12 recall

R2, R3, M1: Early screening review clinic or HES (triaged pending progression/severity)

Front 46

What should you refer the same day?

Back 46

–Sudden loss of vision

–Vitreous haemorrhage

–Retinal detachment

–High IOP > 30mmHg (NVI)

Front 47

How do you manage background R1?

Back 47

AIM: to prevent progression

• Control HbA1c/BP/lipidprofile/Anaemia

• Consider Aspirin-reduce platelet stickiness

• Education

• Ensure annual eyescreening

Front 48

What stages of DR would need closer monitoring?

Back 48

• Maculopathy (M1)

• Non-Proliferative (R2, Severe) >>Ischaemia

• Proliferative (R3)

• Advanced diabetic eye disease

Front 49

What is the treatment for M1?

Back 49

• Spot laser (focal maculopathy)

• Grid laser (diffuse changes)

• Avoid central fovea (500 microns)

• Monthly Anti-VEGF intra-ocular injections (Lucentis, used in ARMD)

• May be used in conjunction with laser

Front 50

What is the treatment for R2/R3 DR?

Back 50

Non-proliferative (R2, severe)- Prevent progression to R3

• LASER Pan-Retinal Photocoagulation (PRP)

– Scatter pattern

– >> scarring & Visual field loss

– tritan colour vision defect?

• anti-VEGF injections Proliferative (R3)

• Laser (PRP)/Anti-VEGF injections

• Combination therapy

Front 51

What is the treatment for advanced diabetic eye disease?

Back 51

• Vitrectomy for removal of vitreous

• Retinal detachment-surgery

• Iris NV’s: PRP, anti-VEGF, glaucoma therapy