L9 Diabetic Retinopathy

Question 1

Located in the middle layers of the retina and have a “dot-blot” appearance?

Answer 1

Intraretinal Haemorrhages (Feature of Diabetic Retinopathy)

Question 2

Superficial and follow the course of the retinal nerve fibre layer?

Answer 2

Flame-shaped Haemorrhages (Feature of Diabetic Retinopathy)

Question 2

Located in the inner nuclear layer and are the first clinically detectable lesions of diabetic retinopathy?

Answer 2

Microaneurysms (Feature of Diabetic Retinopathy)

Question 3

They have a yellow-waxy appearance with relatively distinct margins. Arranged in clumps or rings.

Answer 3

Hard exudates (Feature of Diabetic Retinopathy)

Question 4

Results in retinal thickening => obscures underlying retinal pigment epithelium and choroid?

Answer 4

Retinal Edema (Feature of Diabetic Retinopathy)

Best detected binocularly with a slit lamp 60D OCT

Question 5

Early Treatment Diabetic Retinopathy Study (ETDRS) risk factors for progression to high-risk Proliferative Diabetic Retinopathy?

Answer 5

• Decreased best-corrected visual acuity (BCVA)
• Increased DME
• Type I v. Type 2 Diabetes
• High levels of HbA1c
• Increased serum lipids

Question 6

Systemic Treatment of Diabetic Retinopathy?

Answer 6

Tight control of glycaemia => reduced risk of development/progression of DR in Type I and 2

Aim for HbA1c of <7.0% (amount of glucose attached to hemoglobin)

Question 7

Pathogenesis and Presentation of Proliferative Diabetic Retinopathy?

Answer 7

Vascular and fibrous tufts arising from the retinal blood vessels => Ramify into a network that spreads either within the retina or at the interface between the retina and the vitreous

Retinal hypoxia is the main driver for neovascularisation

Few pericytes (Regulate vascular diameter), friable and bleed easily

Question 8

Treatment of Proliferative Diabetic Retinopathy?

Answer 8

Question 9

Timing for Panretinal Photocoagulation (PRP) in the treatment of Proliferative Diabetic Retinopathy?

Side Effects of this treatment?

Answer 9

Early Treatment Diabetic Retinopathy Study (ETDRS): performing laser photocoagulation beneficial only in cases where proliferative changes were present or imminent

Side Effects of Laser:

• Visual field restriction (driving problems)
• Choroidal haemorrhage and effusion
• Inadvertent foveal burn & loss of central vision

Question 10

Panretinal Photocoagulation (PRP) vs. Ranibizumab?

Answer 10

Protocol S: Ranibizumab is a better treatment for Proliferative Diabetic Retinopathy, with superior two-year visual acuity gains, particularly in eyes with baseline DME, and dramatically less visual field loss compared to PRP

Ranibizumab treated eyes were less likely to develop Diabetic Macular Edema (DME) and less likely to require vitrectomy

Question 11

Causes blurring and distortion of central vision => Reduced best-corrected visual acuity (BCVA)

Answer 11

Diabetic Macular Edema (DME)

Question 12

Signficance of the Wisconsin Epidemiologic Study?

Answer 12

20% of Type1 and 25% of Type 2 DM will develop DME after 10 years of follow-up

Question 13

Screening will detect diabetic maculopathy but not all maculopathy is clinically significant. What signs are indicative of clinically significant Diabetic Retinopathy?

Answer 13

• Thickening of the retina within 500m of center of macula
• Hard exudates within 500m of center of macula (+ thickening of the adjacent retina)
• Zone of retinal thickening > 1 disc areA any part of which is within one disc diameter of centre of the macula

Question 14

Screening for Diabetic Macular Edema (DME)?

Answer 14

Question 15

Distinguish nonleaking from leaking Microaneurysms (MA)?

Answer 15

Fluorescein Angiography

Question 16

Defines Intraretinal microvascular abnormalities (IrMAs)?

Answer 16

Fluorescein Angiography

(IrMAs): shunt vessels and appear as abnormal branching or dilation of existing blood vessels (capillaries) within the retina that act to supply areas of non-perfusion in diabetic r

Question 17

Delineate areas of capillary non perfusion and widening of the FAZ?

Answer 17

Fluorescein Angiography

foveal avascular zone (FAZ) is a region within the fovea centralis at the centre of the retina of the human eye that is devoid of retinal blood vessels)

Question 18

Can separate the retinal layers to Superficial and deep retinal capillary plexus

Answer 18

Optical Coherence Tomography (OCT) Angiography

Question 19

Treatment of Diabetic Macular Edema?

Answer 19

Question 20

Side effects of Argon Laser Photocoagulation?

Answer 20

USed for Treatment of Diabetic Macular Edema

Question 21

Treatment of Diabetic Retinopathy?

PDR vs. DME

Answer 21

Proliferative Diabetic Retinopathy

• Laser Photocoagulation (PRP)
• Protocol S: Ranibizumab as effective as PRP in treating PDR

Diabetic Macular Edema (DME)

• Argon Laser Photocoagulation
• Intravitreal antiVEGF (Ranibizumab, Aflibercept, Bevacizumab)
• Intravitrial Steroids (Triamcinolone, Dexamethasone, Fluocinolone).

Question 22

When are Intravitrial Steroids (Triamcinolone, Dexamethasone, Fluocinolone) indicated for treatment of DME?

Answer 22

First-line: those with a History of a major cardiovascular event

Second-line: Non-responders to 3-6 injections of antiVEGF (Ranibizumab, Aflibercept, Bevacizumab)