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Neuro Optho
PP8
34
Veterinary Medicine
Professional
08/23/2016

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Cards

Term
What is the least discriminatory reflex for vision assessmet?
Definition
-menace reflex
Term
Which of the vision assessments can test individual eyes?
Definition
-menace and tracking
Term
Describe the results of a vision assessment with a blind dog.
Definition
-negative menace reflex
-negative tracking
-obstacle course: bumps into things and just redirects, smells objects, responds to verbal stimuli
Term
Describe a neurologic vision assessment's results.
Definition
-negative menace reflex
-negative tracking
-obstacle course: does not bump, may demontrate obsessive.compulsive pacing behavior with altered response to obstacles, may become stuck in a corner or between obstacles and make no attempt to redirect
Term
What is the purpose of the palpebral reflex?
Definition
-assess the ability of the eyelids to blink
Term
What is the cranial nerve for the afferent and efferent arms of the menace relfex?
Definition
-afferent: CNII optic nerve
-efferent: CNVI facial nerve
Term
What are the cranial nerves for the afferent and efferent arms of the palpebral reflex?
Definition
-afferent: CNV trigeminal nerve
-efferent: CNVII facial nerve
Term
When can we get a false positive palpebral reflex?
Definition
-when an animal cannot blink due to facial nerve paralysis, the abducent CN VI will retract the globe to compensate
Term
How do we distinguish between a real and false positive palpebral reflex?
Definition
-third eyelid will raise with a false positive ONLY
Term
What is the afferent pathway of the pupillary light reflex?
Definition
-retina => optic nerve => optic chiasm
Term
What is the efferent pathway of the pupillary light reflex?
Definition
-parasympathetic fibers running with CN III oculomotor => ciliary ganglion in orbit => iris
Term
What are the common lesions of the retina that affect pupillary light reflex?
Definition
-detachment and degeneration
Term
What are the common pathologies of the optic nerve that affect the pupillary light reflex?
Definition
-inflammation
-neoplasia
-degeneration: post-proptosis, glaucoma
-compression: masticatory myositis
Term
What pathology affects the otpic chiasm that will affect the pupillarylight relfex?
Definition
-neoplasia
Term
Where are the common efferent PLR areas of pathology affecting the pupillary light reflex?
Definition
-parasympathetic fibers running with CN III oculomotor nerve
-ciliary ganglion in the orbit
Term
What commonly affects the ciliary ganglion in the orbit of the eye affecting the pupillary light reflex?
Definition
-FeLV
Term
What pathologies affect the iris that can affect the pupillary light reflexes?
Definition
-atropine
-iris muscle atrophy
-adhesions of the iris to the lens from inflammation
-infiltrative disease of the ris
-glaucoma
Term
What are the components of the visual pathway?
Definition
-Clear media: cornea, aqueous, lens, vitreous
-retina
-optic nerve
-chiasm
-optic triacts
-optic radiations
-visual cortex
Term
What are the afferent components of the PLR pathway? Efferent components?
Definition
-Afferent: retina, optic nerve, chiasm
-Efferent: parasympathetic fibers of CN III, ciliary ganglion, iris constrictor muscle
Term
True or FAlse: A cortically blind animal will not have a normal PLR.
Definition
-FALSE, a cortically blind animal will have a normal PLR
Term
How will a lesion in the following locations affect the pupillary light reflexes?
a) retina
b) optic nerve(s)
c) chiasm
d) visual cortex of the brain
Definition
a) most commonly weak but can be variable
b) max dialated pupils with absent PLR
c) max dilated pupils with absent PLR
d) normal PLRs
Term
Definition: Anisocoria
Definition
-unequal pupil size
Term
Describe the innervation of the dilator muscle as opposed to the constrictor muscle.
Definition
-DIlatory muscle: under sympathetic control
-Constrictor muscle: under parasympathetic control
Term
What happens to the pupil if it looses sympathetic control? WHat about if it loses parasympathetic control?
Definition
-miotic
-mydriatic
Term
Definition: Ptosis
Definition
-drooping of hte upper eyelid due to loss of sympahtetic innervation to Muller's smooth muscle in the superior eyelid
Term
What are the clinical signs of Horner's syndrome?
Definition
-miosis
-prolapsed nictitants
-ptosis
-NO BLEPHAROSPASM
Term
What are the clinical signs of HOrner's syndrome in horses?
Definition
-ptosis
-sweating on head and neck of affected side
-increased warmth of head and neck on affeced side
-only subtle miosis and nictitans prolapse
Term
What are the etiologies of horner's syndrome in dogs and cats?
Definition
-idiopathic (70%): Goldens
-otitis media/ interna
-aggressive ear cleaning
-thoracic mass: mediastinal lymphoma in cats
Term
What are the etiologies of horner's syndrome in horses?
Definition
-equine protozoal myeloencephalitis
-jugular venipuncture attempts or perivascular injection
Term
What diagnostics do we perform for Horner's syndrome?
Definition
-otoscopic exam
-imaging of tympanic bulla
-thoracic rads
Term
How do we treat horner's syndrome?
Definition
-no treatment: non-painful, does not affect vision
Term
What are the clinical signs of favial nerve paralysis?
Definition
-negative palpabral reflex with normal facial sensation
-tearing over flaccid lower eyelid
-ipsilateral ear and lip droop
-may see globe retraction and nictitans prolapse
Term
What are the etiologies of facial nerve paralysis?
Definition
-otitis media/ interna
-folowing total ear canal ablation surgery
-idiopathic (Cockers)
-hypothyroud neuropathy
-trauma: especially in equine, FA, camelids
-neoplasia
Term
How do we treat facial nerve paralysis? What about in the case of exposure keratopathy?
Definition
-treatment not usually required
-lubricants, temporary tarsorrhapthy especially in lLA, lateral peranent tarsorrhapthy
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