Lecture IX Flashcards
How long does occlusion therapy last for in children?
Must be continued through the patient’s first decade
What has to be treated first, and why: strabismus or amblyopia?
Amblyopia, since need to have good vision to affect strabismus
What is the advantage of atropine therapy?
Child can still use better seeing eye for distance, but switches at near to amblyopic eye
When should EOM surgery be done, relative to treatment for amblyopia?
Treat amblyopia before EOM surgery
What is the role of vision therapy in treating amblyopia or strabismus
No proven value
What is recession type surgery for strabismus?
The muscle is detached from the eye, moved to a new position
What is resection type surgery for strabismus?
Section of muscle is removed to shorten the muscle–this lightens the muscle’s pull on the eye
Immediate referral , or less emergent need for referral: Poor red reflex in one or both eye
Immediate
Immediate referral , or less emergent need for referral: intermittent strabismus on exam
Less emergent
Immediate referral , or less emergent need for referral: concern about vision by parent or dr
Immediate
Immediate referral , or less emergent need for referral: asymmetric or diminishing VA
Immediate
Immediate referral , or less emergent need for referral: associated syndromes or systemic disease
Less emergent
Immediate referral , or less emergent need for referral: constant or acute-onset strabismus
Immediate
True or false: amblyopia does not present without strabismus
False
If there is a poor red reflex, or poor vision or large eyes, what must be r/o? (3)
Cataracts
Retinal disease
Glaucoma
Premature infants less than 1250-1500 g should be examined how often for vision problems?
4 weeks and every 3 weeks until vessels to ora serrata
Why are ocular s/sx so relevant to neuro?
Large portion of the brain is utilized for vision
What is the role of the edinger Westphal nucleus?
is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.
What is the role of the pretectal nucleus?
a midbrain structure composed of seven nuclei and comprises part of the subcortical visual system.
It is involved primarily in mediating behavioral responses to acute changes in ambient light such as the pupillary light reflex, the optokinetic reflex, and temporary changes to the circadian rhythm
Lesion to CN III produces what pupillary defect?
Dilation
What are the s/sx of Adie’s tonic pupil?
- Blurred vision
- Periocular discomfort
- Decreased depth perception
Which gender is usually affected with Adie’s tonic pupil?
Women
What is the cause of Adie’s pupil?
damage to the postganglionic fibers of the parasympathetic innervation of the eye, usually by a viral or bacterial infection which causes inflammation, and affects the pupil of the eye and the autonomic nervous system
What is the ganglion that CN III synapses in?
Ciliary ganglion
How do you diagnose Adie’s pupil?
Small dose pilocarpine. Normal pupil will not constrict, but affected pupils are hypersensitive
What are the three major causes of unilateral small pupil?
- Physiologic anisocoria
- Horner’s syndrome
- Argyll Robertson pupil
What is the role of Mueller’s muscle? Innervation?
Part of the levator superioris muscle
CN III
CN 7 defect has what effect on the eye?
Keeps the eye open
CN 3 defect has what effect on the eye?
Closed
What is the SNS innervation of the eye?
C8 ish area
Why do Pancoast tumors cause Horner’s syndrome?
Pathway of SNS goes beneath the subclavian
How do you diagnose Horner’s syndrome?
Apraclonidine (a2 agonist) reverses anisocoria brought about by cocaine
What causes the darkening of the eyes as children age? What is the effect of Horner’s syndrome on this process?
Sympathetic innervation
Will decrease pigment deposition
What is the MOA of clonidine on the eye?
Alpha 2 agonist–causes contraction of the dilator muscle
What is Argyll Robertson pupil?
- Pupils accommodate, but do not react to light
- Pupils are irregular and small
What causes Argyll Robertson pupil?
- Syphilis
- DM retinopathy
- Alcoholism
What is checked with EOMs? (3)
- Diplopia
- Paresis/palsy
- Nystagmus
Onset of diplopia during heavy exercise = ?
Aneurysm
Onset of diplopia when fatigued = ?
MG
Onset of diplopia when looking to the right?
CN VI od
Onset of diplopia associated with HA or retro orbital pain = ?
Aneurysm
What are the etiologies of CN III palsies?
- Intracranial aneurysms
- Vascular dz
- Trauma
- Brain tumor
What are the eye characteristics of CN III palsies?
- Abduction
- Horizontal and vertical diplopia
- Ptosis
Why are vascular diseases that affect CN III pupil sparing?
Pupillary fibers are on the outside of the fiber, which means that they are the last affected with compromised blood supply
What are the characteristic findings of CN palsies in terms of the cardinal eye movements?
LR is constantly active, thus will constantly look laterally
New onset of R ptosis, exotropia, and hypotropia = ?
CN 3 palsy
A pupil involved CN III palsy is a (__) until proven otherwise
Aneurysm or PCA
What are the symptoms of IV CN palsy (type of diplopia and compensation)?
- Vertical oblique diplopia
- Compensatory head tilt to opposite shoulder
What are the etiologies of CN IV palsies?
-Microvascular disease (DM, HTN)
What are the symptoms of CN VI palsy?
- Loss of abduction
- Horizontal diplopia
What are the etiologies of CN VI palsy? (2 nonobvious)
- Increased ICP
- Demyelinating dz
How do you assess for CN V palsies?
Checking corneal sensitivity with cotton wisp
How do you assess for CN VII palsy?
Checking for weakness in patient’s smile or ability to close eye
What are the ocular s/sx of MG?
Ptosis/diplopia
- No pupil findings
- Fatigability
How do you diagnose MG?
Edrophonium
How do you name Nystagmus?
Named by the fast movement
What are the different types of nystagmus?
- Horizontal
- Vertical rotatory
- Combination
What are the three major benign causes of nystagmus?
- End gaze
- Drug induced
- Congenital (blind)
True or false: occlusion therapy will treat strabismus
False
True or false: glasses therapy will treat strabismus
True for some forms of strabismus
What are the extremity findings of Adie’s syndrome?
Absent knee and ankle jerks
What is the prognosis for Adie’s pupil?
Benign
Which CN injury will cause a vertical diplopia?
CN IV
Which CN injury will cause a side-by-side diplopia?
CN VI
