L2: Acute red eye disorders

Question 1

Where is the tear film found?

What is the purpose of the tear film?

Answer 1

Found over the cornea.

Smooths out irregularities of the surface of the eye.

Helps us see better than if we had dry eye.

Question 2

THREE characteristics of cornea

Answer 2

Lots of blood vessels & nerves –> infections can be quite painful

Only senses non-specific pain –> eg. if eye poked, entire eye hurts.

Leads to reflex tearing.

Question 3

What is the purpose of the iris?

Answer 3

Control pupil size

Question 4

Where is aqueous humour found?

What does it do?

Answer 4

Found in the anterior chamber (between cornea & iris).

Exerts pressure on anterior chamber walls –> if too high = risk factor for glaucoma

Question 5

What is the purpose of the lens?

What can go wrong with the lens?

Answer 5

Accommodation: focusing on near and far objects. Worsens with age (presbyopia; lou fa)

May become cloudy due to oxidative stress, UV exposure –> cataract

Question 6

What is the sclera?

Answer 6

Tough fibrous outer layer of eye for protection.

Changes to cornea at the front.

Question 7

What is the purpose of the choroid?

Answer 7

Provides nutrients to the retina

Question 8

What is the purpose of the retina?

Answer 8

Takes light that is focused from cornea & lens and converts it into electrical signals to send to optic nerve.

Question 9

What are FIVE red flag symptoms with red eyes?

PREPS

Answer 9

Pain in or around eye –> herpes zoster/shingles

Reduced vision –> esp. after eye surgery

Eye or eyelid swelling –> something might be pushing the eye forward; may cause double vision (think Graves’ disease)

Photophobia

Sudden onset

Question 10

What are THREE causes of red eye that are NOT sight-threatening?

Answer 10

Conjunctivitis

Episcleritis

Subconjunctival haemorrhage

Question 11

What are EIGHT causes of red eye that CAN BE sight-threatening?

Answer 11

Foreign bodies & abrasions
Chemicals
Blunt force trauma
Scleritis
Keratitis
Acute anterior uveitis
Acute angle closure glaucoma
Contact lens overwear (unless designed otherwise)

Question 12

Foreign bodies & abrasions

Sight-threatening?
Notes
Treatment

Answer 12

Sight-threatening

Trauma itself may be sight-threatening, & damage caused by foreign body may be a site of secondary infection

Remove foreign body immediately
CHLORAMPHENICOL –> prophylaxis for secondary infection

Question 13

Chemicals

Sight-threatening?
Notes
Treatment

Answer 13

Sight-threatening

Damage done within 90 seconds.
Acids cauterise wound –> additional “barrier” to stop penetration into eye
Alkalis can penetrate eye & damage internal contents

IRRIGATION as soon as possible for 15 minutes
Hospital assessment as soon as possible

Question 14

Blunt force trauma

Sight-threatening?
Notes
Treatment

Answer 14

Sight-threatening

Can damage all parts of eye
Can rupture inner blood vessels which leak into anterior chamber –> affect IOP

REFER for hospital assessment immediately