Common Medical Retinal Diseases

Question 1

What % of the UK population does diabetes affect?

Answer 1

4%

Question 2

How many more times is someone who is diabetic likely to blind than someone who is not?

Answer 2

25%

Question 3

How does diabetes affect the eye?

Answer 3

Hyperglycemia –> damage

Increased vascular permeability leads to leakage from the blood vessels, blot haemorrhages and the formation of hard exudates.

Damage to the blood vessel walls leads to microaneurysms and venous beading (sausage shaped)

Damage to nerve fibres in the retina causes fluffy white patches to form on the retina called cotton wool spots.

Intraretinal microvascular abnormalities (IMRA) is where there are dilated and tortuous capillaries in the retina. These can act as a shunt between the arterial and venous vessels in the retina.

Neovascularisation - new blood vessels

Question 4

What are the classifications of diabetic retinopathy?

Answer 4

Non-proliferative
Proliferative

N.B. also a condition: ‘diabetic maculopathy’

Question 5

What are the risk factors of DM?

Answer 5

Duration of DM
Age
Smoking 
Hypertension
Poor DM control
Hyperlipidaemia
Nephropathy 
Pregnancy

Question 6

What is the clinical presentation of mild NON-proliferative diabetic retinopathy?

Answer 6

microaneurysms

Question 7

What is the clinical presentation of moderate NON-proliferative diabetic retinopathy?

Answer 7

microaneurysms, blot haemorhages, hard exudates, cotton wool spots and venous beading

Question 8

What is the clinical presentation of severe NON-proliferative diabetic retinopathy?

Answer 8

blot haemorrhages plus microaneurysms in 4 quadrants, venous beating in 2 quadrates, intraretinal microvascular abnormality (IMRA) in any quadrant

Question 9

What is the clinical presentation of proliferative diabetic retinopathy?

Answer 9

Neovascuarisation on disc (NVD)
Neovascularisation elsewhere (NVE)
Pre-retinal or vitreous haemorrhage

Question 10

Describe the clinical presentation of diabetic maculopathy

Answer 10

Macular oedema

Ischaemic maculopathy

Question 11

What are the symptoms of non-proliferative DR?

Answer 11

Asymptomatic - occur after 8-10 years of DM

Question 12

What are microaneurysms?

Answer 12

focal dilatations of retinal capillaries which may leak and are usually temporal to the macula

Question 13

What are exudates?

Answer 13

Yellowish-white deposits of lipids in the retina

Question 14

What are cotton wool spots?

Answer 14

greyish white poorly defined fluffy edged lesions on the retina caused by infarction

Question 15

What is venous beading?

Answer 15

Venous beading is where the walls of the veins are no longer straight and parallel and look more like a string of beads or sausages

Question 16

What is IRMA?

Answer 16

Intraretinal microvascular abnormalities (IMRA) is where there are dilated and tortuous capillaries in the retina. These can act as a shunt between the arterial and venous vessels in the retina.

Question 17

What is diabetic maculopathy?

Answer 17

Specific type of DR and affects the macula.

Can occur in PDR or non-PDR.

Question 18

What types of maculopathy can occur in Diabetic maculopathy?

Answer 18

Focal leakage - retinal thickening and hard exudate

Diffuse - diffuse retinal thickening, but usually no exudate

Ischaemic - due to closure of the perifoveal capillary network

MIXED (Ischaemia and exudate)

Question 19

How else does diabetes affect the eye?

Answer 19

Increased incidence of eyelid infections and cataracts

Cranial nerve palsies of 3, 4 and 6

Delayed healing of corneal abrasions and corneal ulcers

More severe post-operative intraocular inflammation

Abnormal wound healing

Question 20

What are the complications of diabetic retinopathy?

Answer 20

Retinal detachment
Vitreous haemorrhage (bleeding in to the vitreous humour)
Rebeosis iridis (new blood vessel formation in the iris)
Optic neuropathy
Cataracts

Question 21

What is the treatment of proliferative diabetic retinopathy?

Answer 21

Laser photocoagulation
Anti-VEGF medications such as ranibizumab and bevacizumab
Vitreoretinal surgery (keyhole surgery on the eye) may be required in severe disease

Good glycemic control

Question 22

What are the two types of MD?

Answer 22

Dry (atrophic)

Wet (neovascular)

Question 23

How does Macular degeneration occur?

Answer 23

Due to atrophy of the photoreceptors in the retinal pigment epithelium
Starts with atrophy of the RPE and inner choroid and leads to death of photoreceptors

Drusen are yellow deposits of proteins and lipids that appear between the retinal pigment epithelium and Bruch’s membrane.

Question 24

What % of AMD is dry?

Wet?

Answer 24

90% DRY

10-20% WET

Question 25

What is wet MD caused by?

Answer 25

Due to abnormal vessels growing from the choroid layer (neovascularisation) into the retina These vessels can leak fluid or blood and cause oedema and more rapid loss of vision. A key chemical that stimulates the development of new vessels is vascular endothelial growth factor (VEGF)

Question 26

What % of AMD is wet?

Answer 26

10-20% BUT 80-90% of severe visual loss in AMD

Question 27

What is Drusen?

Answer 27

Focal thickening of Bruch's membrane (the membrane separating the RPE from the choroid layer/photoreceptors) which separates the photoreceptors from the choroid and hence their blood supply

Question 28

What are the risk factors for AMD?

Answer 28

``` Age Smoking White or Chinese ethnic origin Family history Cardiovascular disease ```

Question 29

What is the presentation of dry AMD?

Answer 29

Gradual worsening central visual field loss Reduced visual acuity Crooked or wavy appearance to straight lines

Question 30

What is the presentation of Wet AMD?

Answer 30

presents more acutely. It can present with a loss of vision over days and progress to full loss of vision over 2-3 years. It often progresses to bilateral disease.

Question 31

What are the signs of AMD on examination?

Answer 31

Snellen - reduced acuity Scotoma: reduced central vision Amsler grid (test straight lines) Fundoscopy: key findings Slit lamp other methods by ophthalmology lol I didn't;t know what they were

Question 32

how is AMD managed?

Answer 32

Dry - no real treatment - lifestyle measures Wet: Anti VEGF such as ranibizumab, bevacizumab and pegaptanib They are injected directly into the vitreous chamber of the eye once a month. They slow and even reverse the progression of the disease. typically need to be started within 3 months to be beneficial

Question 33

What is hypertensive retinopathy?

Answer 33

damage to the small blood vessels in the retina relating to systemic hypertension. This can be the result of years of chronic hypertension or can develop quickly in response to malignant hypertension.

Question 34

What are the signs of hypertensive retinopathy?

Answer 34

Silver wiring - Walls of arterioles become thickened, increasing reflection of light AV nipping - arterioles cause compression of the veins where they cross Cotton wool spots - ischaemia and infarction in the retina causing damage to nerve fibres Hard exudates - damaged vessels leaking lipids into the retina Retinal haemorrhages - damaged vessels leaking lipids into the retina Papilloedema - ischaemia to the optic nerve resulting in optic nerve swelling (oedema) and blurring of the disc margins

Question 35

What is stage 1 hypertensive retinopathy?

Answer 35

Arteriolar narrowing and tortuosity | Increased light reflex - silver wiring

Question 36

What is stage 2 hypertensive retinopathy?

Answer 36

Focal constriction of blood vessels and AV nipping

Question 37

What is stage 3 hypertensive retinopathy?

Answer 37

Cotton-wool exudates | Flame and blot haemorrhages

Question 38

What is stage 4 hypertensive retinopathy?

Answer 38

Papilloedema

Question 39

What is the management of hypertensive retinopathy?

Answer 39

Controlling the blood pressure and other risk factors such as smoking and blood lipid levels.