Flashcards in Vision Problems 2- Oculomotor Deck (33):
What is strabismus
misalignment of the visual axies
Paralytic (non-comitant) strabismus
characterized by the presence of variable angles of deviation in different fields of gaze.
- Diplopia (double vision)
- No amblyopia (lazy eye)
What is generally the cause of paralytic strabismus?
weakness of one of the extra-ocular muscles.
Non-paralytic strabismus or comitant strabismus
- Angle of deviation remains constant in different fields of gaze
- No diplopia- brain suppresses one of the images
- no identifiable muscle weakness
Visible deviation always
visual deviation only when fusion is disrupted (covering one eye)
duction refers to
movement of one eye
version refers to
movement of both eyes
movement of both eyes in the same direction...like convergence where both move towards the nose
Rotation of the 12 o'clock position of the cornea toward the nose
What muscles control intorsion?
superior rectus and superior oblique
rotation of the 12 o'clock position away from the nose....inferior rectus and inferior oblique
just know how the different muscles are affecting eye movement at different gazes etc..
rhythmic, involuntary, to and from motion of the eyes. Motion may be horizontal, vertical, rotary, or combinations of directions
generally seen in neurological disorders
equal amplitude to and fro, usually seen in poor vision
when the seeing of two images is relieved by closing eother eye. Generally the result of paresis of an EOM
goes away when the pt closes the affected eye but does not go away if they close the unaffected eye
Monocular diplopia usually the result of
irregularities in the optical system of the eye
CN III symptoms
- weakness of MR, SR, IR, IO
- Ptosis (weakened levator)
- Non-reactive pupil
- eye down and out
THIS IS SERIOUS
common cause of CN III palsy
Aneurysm at the junction of the post communicating and posterior cerebral
Paralysis of CN III with normal pupilary responses
Usually a microvascular cause. Patients are generally elderly, have diabetes or hypertension.
May have mild pain at onset.
Recovery within 3-4 months spontaneous
CN VI palsy
causes loss of abduction by the eye, the medial rectus then pulls the eye in causing esotropia
Esotropia increases as the patient looks?
towards the side of the lesion...think about it. It makes sense