Strabismus and Amblyopia

Question 1

What is a paralytic squint?

Answer 1

A squint that doesn’t move on the cover test; also diplopia

Aetiology: head trauma, cerebrovascular disease, space occupying lesion (tumour/haemorrhage/abscess/aneurysm), raised ICP, DM

Everyone with a paralytic squint (regardless of age - so always check in older patients too), especially if new onset - emergency call/referral to ophthalmology for same day r/v and head scan - treat cause

Question 2

How does a CN3 palsy present?

Answer 2

Innervates: levator palpabrae superioris, superior rectus, medial rectus, inferior rectus, inferior oblique; parasympathic fibres to ciliary ganglion then to constrictor pupillae and ciliary muscles

Ptosis; Dilated and unreactive (to light) pupil; Double vision in all directions except for lateral gaze to the side of the lesion

Aetiology:

Question 3

How does a CN4 palsy present?

Answer 3

Innervates: superior oblique

Question 4

How do you perform a cover test?

Answer 4

Idk