Common medical retinal diseases (AMD + DR)

Question 1

Briefly describe the pathology in dry macular degeneration (MD).

Answer 1

atrophy of the photoreceptors in the retinal pigment epithelium due to age

leads to death of the photoreceptros

This is all caused by Drusens (soft thickenings of Bruch’s membrane) as Drusens separate the photoreceptors from the choroid and hence their blood supply.

Drusens are made of extracellular material and are white or yellow in colour

Question 2

Briefly describe the pathology in wet macular degeneration (MD).

Answer 2

Abnormal vessels growing from the choroid (neovascularisation) and underneath the retina.

These vessels bleed and leak fluid which subsequently leaks and result in scar formation.

Question 3

What is seen on the fundus in dry MD?

Answer 3

Drusens

Question 4

What is seen on the fundus in wet MD

Answer 4

abnormal blood vessel growth

fibrous scar formation

haemorrhage from abnormal vessels

Question 5

What are the effects of visual fields due to MD?

Answer 5

A blind spot in the central vision and a distortion of vision

Question 6

What is diabetic retinopathy?

Answer 6

essentially a retinal vasculopathy

and affects the retinal precapillary arterioles, capillaries and venules

Question 7

What are the two types of diabetic retinopathy (DR)?

Answer 7

Background and

proliferative

Question 8

What is the factors that causes a case of background DR to become proliferative DR?

Answer 8

In proliferative DR there is new blood vessel growth

Question 9

What is maculopathy?

Answer 9

Can occur with background and proliferative DR and is just when it affects the macula.

Question 10

What are the symptoms of non-proiferative diabetic retinopathy (aka background DR)

Answer 10

It is asymptomatic

Question 11

What can be seen on the fundus in background DR?

Answer 11

exudates

retinal haemorrhages (dots, blots or flames)

cotton wool spots

microaneurysms

vascular dilatations

intraretinal microvascular abnormalities (IRMA)

Question 12

Which vessels do dot, blot and flame haemorrhages come from?

Answer 12

dots + blots come from retinal venules

flames come from retinal arterioles

Question 13

What are exudates

Answer 13

yellowish-white deposits with well-defined edges

they represent precipitation of leaking lipoproteins from diseased retinal vasculature

Question 14

What are cotton wool spots (CWS)?

Answer 14

greyish white poorly defined fluffy edged lesions in the nerve fibre layer.

They represent microinfarcts in the retinal nerve fibres (axoplasmic accumulations)

Question 15

Where do blood vessels grow in proliferative DR?

Answer 15

On the optic disc or surface of the retina.

Question 16

What is a particular concern with neovascularisations in proliferative DR?

Answer 16

neovascularisations are fragile and are likely to bleed with slight traction

resulting in pre-retinal and/or vitreous haemorrhage

ALSO

The development of rubeosis glaucoma

Question 17

What symptoms occur in diabetic maculopathy?

Answer 17

visual loss if not treated

Question 18

What are the three types of diabetic maculopathy?

Answer 18

focal
diffuse
ischemic

Question 19

What causes focal diabetic maculopathy and what signs can be seen?

Answer 19

It is caused by focal leakage from microaneurysms or dilated capillaries

causing:

focal retinal thickening

and surrounding exudates

Question 20

What causes diffuse diabetic maculopathy and what signs can be seen?

Answer 20

It is caused by leaking from dilated capillaries which results in a diffuse retinal oedema

which may be associated with:

some retinal haemorrhages

but usually no exudates.

Question 21

What causes ischemic diabetic maculopathy and what signs can be seen?

Answer 21

It is caused by closure of the perifoveal capillary network and manifests as:

a diffuse oedema plus associated dark haemorrhages.

Fluorescein angiography is important in confirming ischemia.

Question 22

How is diabetic retinopathy treated?

Answer 22

Manage diabetic risk factors

Anti-VEGF if proliferative