41B evaluation of the ocular motor system Flashcards
Define strabismus
-misalignment of the visual axes
What are the two types of strabismus?
- paralytic (non-comitant)
- non-paralytic (comitant)
Paralytic is seen with what ages?
-adults
Non-paralytic is seen with what ages?
-kids usually under six
Paralytic characteristics?
- adults
- angle of deviation varies in different fields of gaze
- diplopia
- no amblyopia
- muscle weakness is identified
Non-paralytic characteristics?
- kids
- angle of deviation remains constant in different fields of gaze
- no diplopia
- amblyopia
- no muscle weakness is identified
Tropia
-visible deviation always
Phoria
-aligned unless fusion disrupted (like covering one eye_
Eso
- inwards
- eyes crossed
Exo
- out ward
- eyes in different directions
Hyper
-one eye higher than the other
Hypo
-one eye lower than the other
Define vergence
-movement of both eyes in opposite directions
Define nystagmus
-to and from oscillations of eyes
horizontal, vertical, or rotary
Jerk nystagmus
- slow then fast recovery
- indicates neurologic process
Pendular nystagmus
- equal amplitude to and fro
- indicates poor vision
Binocular dilopia is the result of
-misalignment of the visual axes
What causes binocular diplopia?
often results from paresis or paralysis of one of the cranial nerves that innervate EOM
Cranial nerve II palsy?
- weakness of MR, SR, IR, IO
- Ptosis
- non reactive pupil
- eye is down and out
- may be partial or total
Posterior communicating artery aneurysm
- may causes CN III palsy with pupil involved
- Headaches
CN III palsy with normal pupil
-indicates microvascular cause
-older pt
-common with diabetes and HTN
may have mild pain at onset
-recovery within 3-4 months
Cranial nerve VI palsy
- weakness of LR with esotropia
- esotropia and diplopia increase on gaze to the side of the lesion
- non-localizing neurologic sign
Causes of Cranial nerve VI palsy
- increased ICP
- tumor
- trauma
- stroke
- microvascular
