Diabetic Retinopathy 2

Question 1

Preproliferative DR

1. Definition?
2. Significant clinical sign in retina?
3. Sign on FFA?

Answer 1

1. Background DR that shows signs of imminent proliferative disease is called preproliferative DR (PPDR)
2. Clinical signs indicate progressive retinal ischaemia
3. FFA shows extensive hypo-fluorescent areas ⇒ representing r_etinal non-perfusion (capillary drop out)_

Question 2

3. Preproliferative DR

1. The risk of progressing to proliferative DR depends on ?
2. Can PDR and PPDR co-exist ? one eye or either eye?

Answer 2

1. the number of lesions seen
2. Can have PDR in one eye and PPDR in the other

Question 3

3. Preproliferative DR

Signs on fundus?

Answer 3

a.Cotton wool spots

b.Intraretinal microvascular abnormalities (IRMA)

c.Other changes

•Venous & arterial changes

•Dark blot haemorrhages

Question 4

3. PPDR – a. Cotton wool spots

1. Made up of?
2. Appearance? Location?
3. Cause?
4. How does it heal/ resolve?

Answer 4

1. Made up of accumulations of neuronal debris wihin the NFL
2. Small, white, fluffy superficial lesions - Obscure underlying vessels
3. Caused by disruption of the nerve axons whose ends swell
4. Cotton wool spots can heal & the debris is removed by autolysis* & phagocytosis

* Autolysis: breakdown in the cells by enzymes

Question 5

3. PPDR – b. Intraretinal microvascular abnormalities (IRMA)

1. Describe? Run from where?
2. Location?
3. Difference between IRMA vs Neovascularisation?

Answer 5

1. Fine, irregular red lines - run from the arteries to the venules
2. They are intraretinal - don’t cross major retinal vessels
3. IRMA= Slightly larger than new vessels
   Abnormal branching/ dilatation of existing vessels in retina- always contained to inner retina
   Don’t leak vs late leakage ( in Neovas)
   Neovascular= much finer, delicate, more focal in location ( higher in retina)

Question 6

3. PPDR – c. Other Changes

i) Venous
Signs? (4)

Answer 6

1. Dilated & tortuous veins
2. Looping
3. Beading
4. Sausage-like segmentation

Question 7

3. PPDR – c. Other Changes

ii) arterial changes

Sign?

Answer 7

1. Peripheral narrowing
2. Silver-wiring = Generalised constriction of artery ( silver tone) - resemsble what branch arterial occlusion look like
3. Obliteration ( total destruction)
   Image-: artery occlusion

Question 8

• *3. PPDR – c. Other Changes
  iii) dark blot haemorrhages**

1. Indication of what?
2. Location of what retinal layers

Answer 8

1. Haemorrhagic retinal infarcts
2. Found in the middle retinal layers

Question 9

4. Proliferative DR

1. % of Diabetics popn present with this condition?
2. Which type have higher risk?
3. Protective factors? (4)

Answer 9

1. Affects 5-10% of diabetics
2. Type I diabetics are at risk with 60% having PDR after 30 years
3. Protective factors:

• Ipsilateral carotid occlusion
• Posterior vitreous separation
• High myopia
• Optic atrophy

Question 10

4. PDR – pathogenesis

a. Neovascularization

1. Primary feature?
2. Cause? Why?
3. Impact on which structure of retina?

Answer 10

1. Primary feature is neovascularisation
2. Caused by angiogenic growth factors
   increased by hypoxic retinal tissue in an attempt to re-vascularise the hypoxic retina
3. Angiogenic substances encourage neovascularisation in the retina, ON head & sometimes iris

Question 11

4. PDR – pathogenesis

a. Neovascularization

1. Name angiogenic stimulators?
2. Inhibitors of angiogenesis?

Answer 11

1. Angiogenic stimulators
   Vascular endothelial growth factor (VEGF)
   Placental growth factor
   Pigment epithelium-derived factor
2. Inhibitors of angiogenesis
   Endostatin
   Platelet factor 4
   Angiostatin
3. Image: Left- new vessel at disc (NVD)
   Right: New vessel elsewhere

Question 12

4. PDR – severity

a. Neovascularization

1. Determinded by ?
2. Mild and severe NVD?
3. Mild and severe NVE?

Answer 12

1. Determined by the area covered with new vessels compared with the area of the disc
2. Mild NVD when less than 1/3 of the disk area is covered
   Severe when > 1/3 covered
3. MILD NVE if :
   < 1/2 disc area in size
   SEVERE if more than this

Question 13

4. PDR severity – b. fibrosis

1. Associate with?
2. If signifcant, can predipose to what?
3. Cause?

Answer 13

1. Associated with neovascularisation
2. If significant, can predispose to tractional retinal detachment
3. Progressive contraction of membrane

Image: below: arcuate pattern, extensive retinal detachment

Question 14

5. Advanced diabetic eye disease

1. What is it? Cause?
2. Complication? (4)

Answer 14

1. Serious complications of DR which affect vision can occur in patients who have not had treatment or if treatment has not been successful
2. Complications include:

a. Haemorrhage
b. Tractional retinal detachment
c. Tractional retinoschisis
d. Rubeosis

(c) (abnormal splitting of the retina’s neurosensory layers, usually in the outer plexiform layer)
(d) formation of vessels and connective tissue on the surface of the iris

Question 15

5. Advanced D Eye Disease Complications a.haemorrhage

1. Where?
2. Describe each?
3. Warn patients

Answer 15

1. Pre-retinal or Intragel
2. Pre-retinal : a crescent shape
   Intragel haemorrhages : take longer to clear
   (b/c they result from a more extensive bleed)
3. Warn patients: Bleed may get worse from physical exertion/straining, hypoglycaemia & direct trauma to the eye

Question 16

5. Advanced D Eye Disease Complications b.Tractional RD

Cause?

Answer 16

Caused by progressive contraction of fibro-vascular membranes

Question 17

5. Advanced D Eye Disease Complications c.Retinoschisis
6. What is it?
7. What is good technique for diagnosis?

Answer 17

1. Abnormal splitting of retinal layers ( visually in OPL) - Can occur with/without RD
2. The difference is difficult to determine clinically – OCT can help with diagnosis

Question 18

5. Advanced D Eye Disease Complications d.Rubeosis Irides
6. Lead to what condition if severe?
7. Common in ?

Answer 18

1. Can cause glaucoma if severe
2. Common in eyes with severe retinal ischaemia or persistent retinal detachment following treatment