Diabetic Retinopathy

Question 1

Incidence of DR

Answer 1

after 10 years is 50%, and after 30 years 90%

Question 2

Risk factors for DR

Answer 2

Duration, Poor control, Sudden improvement in control, Pregnancy, Hypertension, Nephropathy, hyperlipidaemia, smoking, cataract surgery, obesity and anaemia

Question 3

The most important risk factor

Answer 3

Duration

Question 4

Diabetic macular oedema in pregnancy

Answer 4

usually resolves spontaneously after pregnancy and need not be treated if it develops in later pregnancy

Question 5

Background diabetic retinopathy

Answer 5

microaneurysms, dot and blot haemorrhages and exudates

Question 6

Preproliferative diabetic retinopathy

Answer 6

cotton wool spots, venous changes, intraretinal microvascular anomalies (IRMA) and often deep retinal haemorrhages

Question 7

PDR

Answer 7

neovascularization on or within one disc diameter of the disc (NVD) and/or new vessels elsewhere (NVE) in the fundus

Question 8

Microaneurysms - where in retina

Answer 8

in the inner capillary plexus (inner nuclear layer)

Question 9

Very mild NPDR

Answer 9

Microaneurysms only

Question 10

Mild NPDR

Answer 10

Any or all of: microaneurysms, retinal haemorrhages, exudates, cotton wool spots, up to the level of moderate NPDR

Question 11

Moderate NPDR

Answer 11

Severe retinal haemorrhages (more than ETDRS standard photograph 2A: about 20 medium–large per quadrant) in 1–3 quadrants or mild IRMA • Significant venous beading can be present in no more than 1 quadrant

Question 12

Severe NPDR

Answer 12

The 4–2–1 rule; one or more of: • Severe haemorrhages in all 4 quadrants • Significant venous beading in 2 or more quadrants • Moderate IRMA in 1 or more quadrants

Question 13

Very severe NPDR

Answer 13

Two or more of the criteria for severe NPDR

Question 14

Mild–moderate PDR

Answer 14

New vessels on the disc (NVD) or new vessels elsewhere (NVE)

Question 15

High-risk PDR

Answer 15

• New vessels on the disc (NVD) greater than ETDRS standard photograph 10A (about 1/3 disc area) • Any NVD with vitreous haemorrhage NVE greater than 1/2 disc area with vitreous haemorrhage

Question 16

Exudates - where in the retina

Answer 16

outer plexiform layer

Question 17

DME - which layers

Answer 17

between the outer plexiform and inner nuclear layers; later it may also involve the inner plexiform and nerve fibre layers

Question 18

Focal maculopathy

Answer 18

well-circumscribed retinal thickening associated with complete or incomplete rings of exudates. FA shows late, focal hyperfluorescence due to leakage, usually with good macular perfusion

Question 19

Diffuse maculopathy

Answer 19

diffuse retinal thickening, which may be associated with cystoid changes; FA shows mid- and late-phase diffuse hyperfluorescence

Question 20

Ischaemic maculopathy

Answer 20

FA shows capillary non-perfusion at the fovea (an enlarged FAZ) and frequently other areas of capillary non-perfusion at the posterior pole and periphery

Question 21

Clinically significant macular oedema

Answer 21

• Retinal thickening within 500 μm of the centre of the macula • Exudates within 500 μm of the centre of the macula, if associated with retinal thickening; the thickening itself may be outside the 500 μm • Retinal thickening one disc area (1500 μm) or larger, any part of which is within one disc diameter of the centre of the macula

Question 22

Cotton wool spots - where in the retina

Answer 22

within the nerve fibre layer. They are clinically evident only in the post-equatorial retina

Question 23

Intraretinal microvascular abnormalities (IRMA)

Answer 23

arteriolar–venular shunts that run from retinal arterioles to venules, thus bypassing the capillary bed and are therefore often seen adjacent to areas of marked capillary hypoperfusion

Question 24

Intraretinal microvascular abnormalities (IRMA) - FA

Answer 24

focal hyperfluorescence associated with adjacent areas of capillary closure (‘dropout’) but without leakage

Question 25

Focal Laser photocoagulation

Answer 25

Diode or argon burns are applied to leaking microaneurysms 500–3000 μm from the foveola; spot size 50–100 μm, duration 0.05–0.1 s

Question 26

Grid Laser photocoagulation

Answer 26

Burns are applied to macular areas of diffuse retinal thickening, treating no closer than 500 μm from the foveola and 500 μm from the optic disc

Question 27

Clinically significant macular oedema (CSMO) not involving the macular center - treatment

Answer 27

photocoagulation, or with micropulse laser if available

Question 28

CSMO involving the macular centre but with normal or minimally affected vision - treatment

Answer 28

laser (micropulse may carry a lower risk of foveolar damage) or be observed if leakage arises very close to the fovea. If laser is performed, it is prudent to treat no closer than 500 μm from the perceived macular centre

Question 29

CSMO involving the macular centre and with reduced or reducing vision (6/9–6/90) and significant foveolar thickening - treatment

Answer 29

anti-VEGF treatment, with initial induction using monthly injections for 3–6 months. It is possible that combining anti-VEGF treatment with laser

Question 30

Pseudophakic eyes with CSMO involving the macular centre and 6/9–6/90 - treatment

Answer 30

anti-VEGF treatment (+ laser) or intravitreal preservative-free triamcinolone followed soon afterwards by laser

Question 31

PDR - treatment

Answer 31

Scatter laser treatment (panretinal photocoagulation),

Question 32

PDR - reduce of vision loss

Answer 32

Severe NVD without haemorrhage carries a 26% risk of visual loss at 2 years that is reduced to 9% with PRP

Question 33

CSMO and PDR - treatment

Answer 33

laser for CSMO prior to PRP or at the same session. ; adjunctive intravitreal steroid or an anti-VEGF

Question 34

Retinal burn diameter in PRP

Answer 34

400 μm

Question 35

How many burns in PRP

Answer 35

2500–3500 burns for regression of mild PDR, 4000 for moderate PDR and 7000 for severe PDR

Question 36

Indicators of regression of PDR

Answer 36

blunting of vessel tips, shrinking and disappearance of NV, often leaving ‘ghost’ vessels or fibrosis, regression of IRMA, decreased venous changes, absorption of retinal haemorrhages, disc pallor

Question 37

Indications for pars plana vitrectomy

Answer 37

Severe persistent vitreous haemorrhage that precludes adequate PRP, Progressive tractional RD threatening or involving the macula, Premacular retrohyaloid haemorrhage

Question 38

Diabetic papillopathy (diabetic papillitis)

Answer 38

variant of NAION, bilateral, more diffuse disc swelling,