Common conditions of the eyes

Question 1

what conditions(s) cause opacification of the eyes and what part does it affect?

Answer 1

cataract - opacification of the lens
corneal degeneration/dystrophie - opacification of the cornea
angle closure glaucoma

Question 2

what is glaucoma?

Answer 2

raised intraoccqular pressure

Question 3

what is the triad of symptoms which indicate glaucoma?

Answer 3

raised intraoccqular pressure
vision field defects
optic disc changes on ophthalmoscopy

Question 4

what are the 2 types of glaucoma?

Answer 4

open angle glaucoma (POAG)

closed angle glaucoma

Question 5

what does the fundus pictures look like in ophthalmoscopy in someone with glaucoma?

Answer 5

optic disc is cupped , pale and appears unhealthy

Question 6

how does IOP cause visual defects?

Answer 6

the raised pressure puts pressure on the nerve fibres which lie on the surface of the retina
this results in the nerve fibres dying
because never fibres are dying this puts pressure on the optic nerve head

Question 7

how is primary open angle glaucoma treated?

Answer 7

eyedrops to decrease IOP
- prostaglandin anologues
- beta blockers 
- carbonic anhydrase inhibitors 
laser trabeculoplasty 
trabeculotomy surgery

Question 8

describe the clinical presentation of closed angle glaucoma.

Answer 8

sudden onset
red, painful eye with visual loss
headache (often confused with migraine)

Question 9

how does closed angle glaucoma result in raised IOP?

Answer 9

suddenly something causes the angle of the anterior chamber to close
therefore this blocks the trabecular meshwork for the aqueous humour to drain into
the pressure therefore builds as it cannot drain

Question 10

what causes the angle to close in closed angle glaucoma?

Answer 10

functional block in a small eye - lens too big
mid-dilated pupil - periphery of iris crowds around the angle so outflow is obstructed
the iris sticks to pupillary border which causes the iris to dilate anteriorly blocking the angle

Question 11

how do you treat angle closure glaucoma?

Answer 11

decrease IOP;
- IV infusion carbonic anhydrase inhibitors
analgesia, antiemetics 
constrictor eye drops 
beta blocker eye drops i.e. timolol
steroid eye drops 
iridotomy

Question 12

what is the difference in the raised IOP of closed and open angle glaucoma?

Answer 12

closed is sudden and acute causing red and painful eye

open is gradual and painless

Question 13

what is the difference in the drainage of the aqueous humour in open compared to closed angle glaucoma?

Answer 13

in open angle - drainage through trabecular meshwork is obstructed
in closed angle - the peripheral iris is blocking the angle of the anterior chamber so its more sudden

Question 14

what are he 2 different types of hordeolum/stye’s?

Answer 14

external = infection affecting sebaceous glands of eyelashes
internal = infection affecting meibomian glands of tarsal plate

Question 15

does conjunctivitis cause vision loss?

Answer 15

no, not unless the infection spreads to the cornea

Question 16

how would you treat bacterial conjunctivitis?

Answer 16

antibacterial eye drops

Question 17

what may differentiate anterior uveitis from intermediate and posterior?

Answer 17

in anterior uveitis the iris leaks plasma and WBC which can be seen during slit lamp examination as a hazy anterior chamber and cells deposited in the back of the cornea
in anterior uveitis the anterior chamber may settle inferiorly

Question 18

what is the difference between anterior, intermediate and posterior uveitis?

Answer 18

anterior - inflammation of iris
intermediate - inflammation of ciliary body
posterior - inflammation of choroid

Question 19

how does posterior uveitis cause blurred vision?

Answer 19

because the choroid sits onto of the retina, infection can easily spread to the retina causing blurred vision

Question 20

in what condition is the ciliary body inflamed and what does an inflamed ciliary body do?

Answer 20

intermediate uveitis

causes leakage of cells and proteins

Question 21

what type of cells does anterior uveitis leak?

Answer 21

WBC and plasma cells

Question 22

what is cataract?

Answer 22

lens opacification

Question 23

why does cataract develop?

Answer 23

embryological/foetal fibres are never shed - they are compacted in the middle of the lens
due to no blood supply it relies on diffusion for nutrition
the lens absorbs harmful UV rays to protect the retina from harm
this all causes damage to the lens fibres causing opacification

Question 24

what is the treatment for cataract?

Answer 24

surgery to replace cataract lens with a posterior chamber intra ocular lens (PCIOL)

Question 25

states some of the features of corneal dystrophies/ degenerations.

Answer 25

bilateral 
opacifying 
non-inflammatory 
mostly genetically determined 
sometimes they are due to the accumulation of substances within the cornea such as lipase

Question 26

what is the treatment for corneal degeneration or dystrophies?

Answer 26

corneal transplant

Question 27

what is the clinical presentation of corneal dystrophies / degeneration?

Answer 27

start in 1st to 4th decade of life
decreased vision
start in 1 corneal layer and spreads

Question 28

what is the aetiology of corneal ulcer?

Answer 28

bacterial/viral/fungal infection

Question 29

what is the aetiology of conjunctivitis?

Answer 29

bacterial or viral infection

Question 30

what are the causes of uveitis?

Answer 30

isolated illness
non-infectious autoimmune causes - presence of HLA-B27 predisposes
infectious i.e. TB
associated with systemic illness i.e. alkalising spondylitis