Pathology

Question 1

What name is given to the outer layer of the lens?

Answer 1

Epithelium

Question 2

What is special about the epithelium of the lens in comparison to other epithelia in the body?

Answer 2

Epithelium of the lens has no potential for malignancy

Question 3

How is cataracts defined?

Answer 3

Opacification of the lens due to clouding or scratches

Question 4

What percentage of blindness worldwide is caused by cataracts?

Answer 4

50%

Question 5

What are the main causes of cataracts?

Answer 5

Age related degeneration of the nerve fibres
=> opacification

Sun damage (UVB)

Question 6

What factors can increase the risk of developing cataracts?

Answer 6

Hypertension
Smoking
Post-operative OR Trauma
Genetic/Metabolic disorder
Diabetes

Question 7

How does diabetes cause cataracts?

Answer 7

Changes the osmotic pressure

=> fluid content in lens changes and causes nerve fibres to degenerate

Question 8

What is Glaucoma?

Answer 8

Abnormal increase in pressure behind the eyes

Either too much humour produced, or not being drained quickly enough

Question 9

Describe the course of aqueous fluid in the anterior chamber of the eye

Answer 9

Ciliary Body 
Between Lens and Iris
Over top of Iris
Trabecular Meshwork
Canal of Schlemm

Question 10

What structures in the eye are damaged as a consequence of glaucoma?

Answer 10

Optic disc and nerve

Question 11

Describe the difference between Primary Open Angled Glaucoma and Angle Closure Glaucoma?

Answer 11

Primary Open Angled = poor drainage through trabecular meshwork and in the Canal of Schlemm

Angle Closure = Fluid cant get through to meshwork due to obstruction (e.g. iris)

Question 12

What investigation is used in diagnosis of primary open angles glaucoma?

Answer 12

Applanation Tonometry (Air puff test)
Depending on the eyes resistance to the air, the intra-ocular pressure can be measured

Question 13

Angle Closure Glaucoma usually presents with a slow onset that is often asymptomatic. TRUE/FALSE

Answer 13

FALSE
Primary Open Angled Glaucoma presents this way

Angle closure presents more acutely:

• red eye
• vision loss
• headaches
• Nausea and vomiting

Question 14

What treatment is used when Angle Closure Glaucoma presents as an emergency?

Answer 14

Laser treatment

Question 15

What is the aim of Primary Open Angled Glaucoma treatment?

Answer 15

Therapies are aimed at slowing production of aqueous humour or widening the canal to promote drainage

Question 16

What types of drops are prescribed in Primary Open Angled Glaucoma?

Answer 16

Beta Blocker drops (slow aqueous humour production)
=> e.g. Timolol

Carbonic Anhydrase Inhibitor Drops (slow aqueous humour production) => e.g. Acetazolamide

Prostaglandin drops (aid drainage of humour)
=> e.g. Latanoprost

Question 17

What sign is often seen in the optic disc of patients with glaucoma?

Answer 17

“Cupping”
Edges = rolled
Centre = depressed

Question 18

What is papilloedema?

Answer 18

Bulging of the optic disc in the centre (opposite of cupping)
Due to raised intra-cranial pressure

Question 19

What is the difference between episcleritis and scleritis?

Answer 19

Episcleritis - just on surface (superficial and self-limiting)

Scleritis - More severe with pain on movement - thought to be of autoimmune origin

Question 20

Name the two types of age related macular degeneration (ARMD)

Answer 20

Dry = no vascular proliferation (leaky blood vessels)
Wet = Vascular proliferation/ leaky vessels =>visual loss

Question 21

What is thought to cause ARMD?

Answer 21

Not well known => Underlying inflammatory process

Accumulation of by-products
=> (Drusen - protein/lipid/inflammatory mediators)

Question 22

What is thought to mediate wet ARMD and why is this useful?

Answer 22

Vascular endothelial growth factor (VEGF)

=> can aim monoclonal antibody treatments at this source

Question 23

How does blurred vision relate to diabetes?

Answer 23

This is often a presenting complaint in Type 1 Diabetes Mellitus if patients are otherwise asymptomatic

Question 24

What sign can be seen in the pupils of a diabetic patient?

Answer 24

Argyll-Robertson sign

Accommodates (can move far to near) but doesn’t react (constrict/vasodilate)

Question 25

How is cataracts developed in diabetes?

Answer 25

• Hyperglycaemia causes increased sugar content in the lens
• Glucose converted to sorbitol
• Alters the osmotic gradient and causes swelling and fibre disruption

Question 26

How do diabetic patients develop glaucoma?

Answer 26

New vessel formation (due to hypoxia) obstructs the angle and pressure is allowed to build

Question 27

Describe Diabetic retinopathy

Answer 27

Poor vessel function leads to leaky vessels and small aneurysms
The eye then begins to form new vessels which are fragile!

Question 28

What treatment can be used to remove the newly forming vessels in glaucoma related diabetic retinopathy?

Answer 28

Laser treatment

coagulates the new vessels which are forming

Question 29

What do CRAO and CRVO stand for?

Answer 29

Central Retinal Artery Occlusion

Central Retinal Vein Occlusion

Question 30

What is the most common sight for thromboembolic disease to pass onto the eye?

Answer 30

Common carotids

Question 31

A “transient ischaemic attack” can occur in the eye but goes by a different name, what is this?

Answer 31

Amaurosis Fugax

Question 32

What type of arteritis is important to look for in the eyes?

Answer 32

Giant Cell

Question 33

What tumours can arise in the eyelid?

Answer 33

Basal Cell Carcinoma
Squamous Cell Carcinoma
Melanoma
(Due to sun exposure)

Question 34

Where else in relation to the eye can a primary melanoma present?

Answer 34

Retina (due to melanocytes being present here)