Clinical Pathology of the Eye

Question 1

what is the main pathology of the lens

Answer 1

cataracts

Question 2

what are cataracts

Answer 2

opacifications within the lens

usually age related by has multiple causes

Question 3

what is the main cause of cataracts

Answer 3

degenerative changes in the fibres of the lens due to UV exposure

Question 4

what are some less common causes of cataracts

Answer 4

hypertension 
smoking 
post op and trauma 
metabolic disorders 
genetic 
diabetes

Question 5

what is glaucoma

Answer 5

abnormal increase in the pressure in the eye (intraocular pressure)

Question 6

causes of increase intraocular pressure

Answer 6

too much aqueous humour being produced

the aqueous humour not being properly drained

Question 7

where does aqueous humour normally drain

Answer 7

through the trabecular meshwork into the canal of schlem

Question 8

what is open angled glaucoma

Answer 8

most common cause

poor drainage between the trabecular meshwork or canal of schlem leads to increase IOP which then damages the optic disc and nerve

Question 9

what is primary closed angle glaucoma

Answer 9

when the drainage through the meshwork if fine but the fluid can’t get to the meshwork

fluid can’t pass over the iris into the anterior chamber properly

Acute and site threatening

Question 10

how do you treat open angle glaucoma

Answer 10

pharmacological therapy aimed at widening the canal

Question 11

how do you treat closed angle glaucoma

Answer 11

medical emergency

use a laser to make a hole in the iris and allow the fluid to drain (peripheral iridotomy)

Question 12

what is ‘cupping’ of the optic disc

Answer 12

when raised IOP damages the optic disc and nerve, so the edges of the disc become rolled up and the centre becomes depressed

Question 13

what is papilloedema

Answer 13

swelling of the optic disc/nerve as a result of increased intracranial pressure

Question 14

what is conjunctivitis

Answer 14

inflammation of the conjunctiva - usually viral but can be bacterial or allergic

Question 15

symptoms of conjunctivitis

Answer 15

swelling, redness, pain and heat of the conjunctiva

Question 16

what is the different between episcleritis and scleritis

Answer 16

both inflammation of the sclera however scleritis is more rare and severe and episcleritis is most superficial and self limiting

Question 17

scleritis symptoms

Answer 17

pain on movement

associated with underlying autoimmune aetiology

Question 18

what is ARMD

Answer 18

age related macular degeneration

Question 19

difference between wet and dry ARMD

Answer 19

Dry- no significant vascular proliferation

wet- vascular proliferation

Question 20

what is drusen

Answer 20

by-product seen in ARMD - proteins, lipid and inflammatory mediators

Question 21

What is wet ARMD

Answer 21

Neovascularisation in choroid mediated by VEGF

the new vessels are fragile and leaky so are more likely to result in vision loss

Question 22

treatment for wet ARMD

Answer 22

anti-VEGF injections

Question 23

what effect does hyperglycaemia have on the eye

Answer 23

leads to changes to osmotic pressure in the anterior chamber of the eye (this cause blurred vision)

Question 24

what affect does hyperglycaemia have on the pupils

Answer 24

Argyll Roberston pupil

-pupil accommodates but doesn’t reaction (no constriction or dilation but can focus near/far)

Question 25

how can diabetes cause cataracts

Answer 25

increased sugar content in lens leads to the conversion of glucose to sorbitol (this leads to altered osmotic gradients with swelling and fibre disruption)

Question 26

how can diabetes cause glaucoma

Answer 26

causes Rubeotic glaucoma - new vessel formation obstructions the angle (also seen in severe vensous occlusion)

Question 27

what is diabetic retinopathy

Answer 27

complex mechanisms leading to poor function of vessels

leaky vessels and small aneurysms form

if severe new vessel formation occurs leading to oedema

if the macular is affected the visual loss is worse

Question 28

what arteries can be occluded to cause sight loss

Answer 28

carotids, central retinal artery

Question 29

what veins are occluded to cause sight loss

Answer 29

central venous occlusion

Question 30

which form of vasculitis can lead to sight loss

Answer 30

giant cell vasculitis

Question 31

what cancers are seen in the eye

Answer 31

BCC
SCC
Melanoma
Retinal melanoma