Non-concomitant and concomitant strabismus

Question 1

What is a concomitant strabismus?

Answer 1

An eye misalignment that is the same magnitude in all directions

Question 2

What is a non-concomitant strabismus?

Answer 2

An eye misalignment that in other directions it has no effect on eye movement

Question 3

What are the causes of a non-concomitant strabismus?

Answer 3

Crainal nerve palsy, trauma, muscle dysfunction

Question 4

What is a fourth nerve palsy?

Answer 4

Most common cause of non-concomitant strabismus. Affects the trochlear nerve. The trochlear near nerve affects the superior oblique. Results in hypertropia in primary gaze and increase in adduction. Can cause head tilt or turn to opposite side. Can cause diplopia (when reading)

Question 5

What is a sixth nerve palsy?

Answer 5

Affects the abducens nerve. The abducens nerve affects the lateral rectus muscle. Results in esotropia in primary gaze. Limitation of abduction and head turn on affected side

Question 6

What is a third nerve palsy?

Answer 6

Affects the ocular-motor nerve. The ocular-motor nerve affects the medial, superior and inferior recti and the inferior oblique. Results in large exotropia and mild hypertropia. Can cause diplopia due to levator palpebrae involvement. Possible fixed dilated pupil

Question 7

What is Duane Syndrome?

Answer 7

Prevents abduction of the eye. Can sometimes affect adduction too. May have esotropia in primary gaze. Head turn possible

Question 8

What is Brown Syndrome?

Answer 8

A malfunction of the Superior oblique muscle, causing the eye to have difficulty moving up, particularly during adduction. Increased divergence in up gaze

Question 9

What is a blow-out fracture?

Answer 9

Affects the orbital or medial wall most. Causes swelling and ecchymosis of the lids, diplopia and non-concomitant strabismus. Limitation of elevation and possibly abduction. Hypotropia or esotropia and enophthalmos