Diabetic Retinopathy

Question 1

What is diabetic retinopathy?

Answer 1

Pathological breakdown of retinal vasculature due to persistent hyperglycaemia

Question 2

Classifications of diabetic retinopathy?

Answer 2

A. Non-proliferative i. Background retinopathy ii. Maculopathy B. Proliferative diabetic retinopathy

Question 3

What is background retinopathy?

Answer 3

Mild changes on opthalmoscopy (microaneurysms, small haemorrahges, hard exudates (not macula, but other parts of retina)) but no Sx or changes to vision

Question 4

Rx of background retinopathy

Answer 4

Requires no immediate Rx except controlling BGL so it does not progress

Question 5

What is maculopathy?

Answer 5

Oedema and exudates involving the macula * #1 cause of blindness in pts with diabetic retinopathy (does not even progress to worse form)

Question 6

Sx of maculopathy

Answer 6

Blurring, decreased acuity, darkening, visual distortion

Question 7

What is proliferative diabetic retinopathy?

Answer 7

More advanced stage of diabetic retinopathy, and is associated with poorer outcome. - Neovascularisation from optic disc or major vessels - Associated with vitreous haemorrhaging due to fragile vessels and tractional retinal detachment due to fibrosed vessels - Neovascular glaucoma can occur (vessels narrow the anterior angle)

Question 8

What are microaneurysms?

Answer 8

The earliest clinical sign of diabetic retinopathy; these occur secondary to capillary wall outpouching due to pericyte loss; they appear as small, red dots in the superficial retinal layers

Question 9

What are dot and blot haemorrhages?

Answer 9

Appear similar to microaneurysms if they are small; they occur as microaneurysms rupture in the deeper layers of the retina, such as the inner nuclear and outer plexiform layers

Question 10

What are retinal oedema and hard exudates?

Answer 10

Caused by the breakdown of the blood-retina barrier, allowing leakage of serum proteins, lipids, and protein from the vessels

Question 11

What are cotton wool spots (aka soft exudates)?

Answer 11

Nerve fiber layer infarctions from occlusion of precapillary arterioles; they are frequently bordered by microaneurysms and vascular hyperpermeability

Question 12

What are flame-shaped haemorrhages?

Answer 12

Splinter hemorrhages that occur in the more superficial nerve fiber layer

Question 13

What are venous loops and venous beading?

Answer 13

Frequently occur adjacent to areas of nonperfusion; they reflect increasing retinal ischemia, and their occurrence is the most significant predictor of progression to proliferative diabetic retinopathy (PDR)

Question 14

What are the key fundoscopic signs of non-proliferative diabetic retinopathy?

Answer 14

1. Haemorrhages: a. Dot-haemorrhage into the inner retinal areas b. Blot-haemorrahge into more superficial nerve fibre layers 2. Hard exudates have straight edges - leakage of protein and lipids from damaged capillaries 3. Soft exudates (cotton wool spots) have a fluffy appearnce owing to microinfarcts 4. Microaneurysms 5. Dilated veins

Question 15

What are the signs of proliferative diabetic retinopathy?

Answer 15

1. New vessels 2. Vitreous haemorrhage 3. Scar formation 4. Retinal detachment (oplalescent sheet that balloons forward into the vitreous) 5. Laser scars

Question 16

Diabetic maculopathy is _____ and considered the more _____ form of non-proliferative DR (cf. ______) but does not necessarily progress into _________.

Answer 16

Diabetic maculopathy is symptomatic and considered the more advanced form of non-proliferative DR (cf. background DR) but does not necessarily progress into proliferative DR

Question 17

Sx of diabetic maculopathy

Answer 17

Macula is affected: Loss of visual acuity Scotoma-like black spots in central vision Blurred vision Image distortion esp. relative to other eye

Question 18

Dx of diabetic maculopathy

Answer 18

Opthalmoscopic exam Optical coherence tomography

Question 19

2 causes of diabetic maculopathy

Answer 19

1. Macular oedema - Leakage of fluid into foveal tissue - Lipid exudates adjacent to fovea 2. Macular ischaemia - Capillary non- perfusion at fovea - Enlarged foveal avascular zone and capillary drop-out on fluorescein angiography

Question 20

What is the management for macular oedema?

Answer 20

For diabetic macular oedema: -Macular (grid) laser -Intra-vitreal - Anti-VEGF agents

Question 21

What is the management for macular ischaemia?

Answer 21

-No specific treatment for macular ischaemia -Blood sugar level control -Blood pressure control -Cholesterol control

Question 22

How do we grade NPDR?

Answer 22

Grading -Mild NPDR -Moderate NPDR -Severe NPDR -Very Severe NPDR

Question 23

When is NPDR graded as ‘mild NPDR’?

Answer 23

Mild NPDR: 1. Microaneurysms

Question 24

When is NPDR graded as ‘moderate NPDR’?

Answer 24

Moderate NPDR: 1. Microaneurysms 2. Intra-retinal haemorrhages 3. Hard exudates 4. Cotton wool spots

Question 25

When is NPDR graded as 'severe NPDR'?

Answer 25

Severe NPDR: any 1 feature of the 4:2:1 rule In the most severe stage of NPDR, you will find cotton wool spots, venous beading, and severe intraretinal microvascular abnormalities (IRMA). It is diagnosed using the "4-2-1 rule." A diagnosis is made if the patient has any of the following: 1. diffuse intraretinal hemorrhages and microaneurysms in 4 quadrants 2. venous beading in ≥2 quadrants, or 3. IRMA in ≥1 quadrant

Question 26

When is NPDR graded as 'very severe'?

Answer 26

2 features from the 4-2-1 rule

Question 27

What is proliferative diabetic retinopathy (PDR)?

Answer 27

Most advanced stage of DR where native vessels have endured damage to the point where new vessels form

Question 28

List the classification of PDR

Answer 28

1. Low risk PDR 2. High risk PDR

Question 29

What are the main characteristics of low risk PDR?

Question 30

What are the main characteristics of high risk PDR?

Answer 30

- disc neovascularised (NVD) plus vitreous haemorrhage - NVD \>one third of the disc - NVE (neo-vascularisation everywhere!)

Question 31

What is vitreous haemorrhage?

Answer 31

Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and around the vitreous humor of the eye

Question 32

What are the complications of continued vascular proliferation?

Answer 32

a. Glaucoma: New vessels may progress to the anterior structures and block the angle of the eye which would lead to glaucoma b. Retinal detachment: vessels contract and dead vascular tissue can fibrose and act as a tractional point (when turning the eye with movement) for retinal detachment

Question 33

Sx of PDR

Answer 33

Blurred vision (can be from vitreous haemorrahge or macular oedema) - Floaters (blood in vitreous) - Difficulty w/ night time vision

Question 34

Management of PDR

Answer 34

1st line: Pan-retinal photocoagulation (retinal laser): - Goal: create 2,000 burns in retina with hope of reducing retina's O2 demand in the peripheries and therefore ischaemia - Burns used to destroy the abnormal BVs in periphery - Decreases drive of VEGF production, leading to reduced neo-vascularisation - Peripheral vision sacrificed - Reduces severe vision loss (centre preserved)

Question 35

Dx of PDR

Answer 35

Opthalmoscopic examination Ocular tonometry if shows signs of glaucoma (measure IOP)

Question 36

What does this show?

Answer 36

Early diabetic changes in eyes (background retinopathy)

Question 37

What does this show?

Answer 37

Optical coherence tomography (OCT) in patient with diabetic maculopathy

Question 38

What does this show?

Answer 38

NPDR maculopathy

Question 39

What does this show?

Answer 39

PDR with venous loops and new vessels

Question 40

What does this show?

Answer 40

PDR with vitrious haemorrahge

Question 41

What does this show?

Answer 41

PDR

Question 42

What does this show?

Answer 42

Panretinal photocoagulation

Question 43

Why do people with diabetes go blind?

Answer 43

1. Diabetic maculopathy 2. Glaucoma - neovascularization complication