Intro and exam Flashcards
What nerve is blocked during ophthalmic exam in horses
auriculopalpebral
Purpose of tonometer
estimate intraocular pressure
Preform the Schrmer tear test before doing what
adding fluid to the eye
What tests should you do before dilating the pupil
PLR and IOP
What test should you do before administering topical anesthetic
Corneal sensation
Nerves involved in palpebral reflexes
CN VII
Nerves involved in menace response
Afferent: CNII Efferent: CNVII
What is this
Anisocoria
(left mydriasis)
What is direct PLR
Response of the eye being illuminated
What is indirect PLR
Response of the eye not being illuminated
Is a positive direct PLR a reliable indicator of vision or normal retinal function
No!
Afferent parasympathetic pathway of PLR
photoreceptors
Bipolar cells
Retinal ganglion cells
Optic nerve
Where do axons from the medial retina decussate at
optic chiasm
Where do pupillomotor fibers synapse at
pretectal region
Efferent arm of PLR
Parasympathetic fibers along CN III
Dazzle response afferent nerve
CN II
Dazzle response efferent nerve
Facial nerve (VII)
Best way to preform tracking tests
Cotton ball drop
laser pointer
How do you preform a visual placing exam
animal is held and supported under chest, brought toward a table, animal should raise its leg to stand
Purpose of visual placing exam
Test for vision in small animals with normal motor function and mental status
After preliminary exam, what are the next tests
STT, bacterial, fungal culture needed
Pupillary light reflexes and retroillumination
Tonometry
Dilate with tropicamide
What does Schrimer Tear Test measure
Aqueious portion of the precorneal tear film
What is normal amount for the Schirmer Tear Test
15mm/min or greater
any lower is indicitive of keratoconjunctivitis sicca or decreased tear production
What nerves does the corneal relfex and sensation test
CN V, VI, VII
What are the parts of the eye we examine
Orbit
Eyelids
Third eyelid
anterior segment
conjunctiva
cornea
sclera
anterior chamber
iris and pupil
lens
What light filter do you need with a fluorescein dye test
Cobalt blue filter
What is fluorescein used for
Corneal ulcers
corneal leaks
N-L patency
Tear film breakup
Retinal angiography
Aqueous flow
What does the Jones test used for
naso lacromal issues
What is lissamine green and rose bengal dye used for
Diagnosis of keratoconjuctivitis sicca
Mucin deficiences
eraly punctate
dendritic ulcers associated with herpetic keratitis
How do you determine a positive Jones test
Fluorescein passes out through the nose
What are the indications of a corneal culture
Ulcers with depth
Cellular infiltrate
Collagenolysis
severe edema
What do fluorescein stains show
corneal ulcers
NL passage
Tear film breakup
What do Rose-Bengal and Lissamine green stains show
Cornea and conjunctival cell degernation
Mucin layer deficiency
What does Rose Bengal and Lissamine grean stain
healthy cells not covered by tear ffil components
Devitalized cells
What do you use to look at the anterior segment
bright focal light source
Slit beam
What do you look for in the anterior chamber
Clarity, depth, mass lesions
Anterior uveitis
What is this and what is it indiciative of
Miosis
Anterior uveitis
What is this and what causes it
Mydriasis
Drug induced vs pathologic
Glaucoma
Retinal diesase
What is this and what causes it
Dyscoria- abnormal shape
Synechia
UVitis
Mass lesions
What is corectopia
abnormal position
Parts of lens examination
Transilluminate and retroilluminate- dilate the pupil, use tapetal reflection
Size
Carlity vs opacity- Nuclear sclerosis, cataract
Position- anterior luxation, posterior luxation, subluxation
What are some signs of increased IOP, glaucoma
Clinical signs
pupil size
Tonometry
Gonioscopy
What is the iridocorneal angle
Open meshwork through which aqueous humor flows
What are some problems associated with the iridocorneal angle
Can change, narrow, become fibrotic, and scarred over with inflammation
IOP elevations
Gonioscopy
Visualization of the iridocorneal angle
Posterior segment looks at
Structures posterior to lens:
Vitreous, retina, optic nerve
How do you visualize the posterior segment
Direct/indirect ophthalmoscope
Panoptic
Why do is tropicamide used for eye dilation over atropine
Tropicamide onset: 10-20 min
Atropine onset: 1 hour
Normal vitreous apperance
Not visualized
Congenital abnormalities of the vitreous
Persistant hyaloid artery/remnant
Aquired opacities of the vitreous
Transudates/exudates
Hemorrhage
Asteroid hyalosis- age related
What is the red-free filter used for
observe optic nerve fiber layer and differentiate hemorrhage from pigment
Positive (green or black) setting on ophthalmoscope is used for
anterior segments
Negative setting on direct ophthalmoscope is used for
depression
Why doesn’t red-free filter work in animals
Tepedum
ermergerd optic ferbers
Direct magnification
10-15x
upright and real
small field
panoptic manification
3-7x
upright and real
intermediate field
Indirect magnification
2-4x
upside-down, backwards, virtual
large field
What do we look for in the retinal vessels
Presence/absense
number
tortuous or thin
color
What do we look for in the tapetum
Peripapillary scarring
irregularities
hyper/hyporeflectivitiy
