SAM II Lecture 46

Eye contact; menace response; cotton ball test; obstacle course; visual placing; visual cliff

Place objects in random order in front of dog; ideally test each eye separately; conduct in bright and dim light

0.5% proparacaine HCl; onset of effect in 15-20sec; anesthesia lasts 15-20min; not required for TonoVet

Schirmer tear test strips; fluorescein dye strips; culturette (mini-tip); spatula for cytology; sterile eyewash/saline

Protrusion; color; thickening/swelling; gland position

Many ocular disorders are inherited or at least have a breed disposition; particular age groups

Current problem; previous problems; familial history; general health

Parasympatholytic mydriatic/cycloplegic; maximum dilation in 20min, duration 4-6hr; contraindications

Normal canine 15-20 seconds

What is being shown?

Trauma; conjunctivitis; dry eye; corneal ulcer; uveitis (intraocular inflammation); glaucoma; cataract; vision loss

Discharge; color; swelling; adhesions

Optivisor; surgical loupe; slit lamp; direct ophthalmoscope; otoscope 10x mag; 3x reading glasses

Clarity, contour, color

What is being shown?

Requires functional facial nerve (CN VII); subcortical reflex, so does not rule out central blindness

Clarity, depth, abnormal contents

What is being shown?

What is being shown?

What is being shown?

All parts in focus at same time; nature of tapetal sheen; unusual coloration; retinal vessels + optic nerve head normal

Color; pupil shape + mobility; swelling/thickening

Direct; indirect or consensual; retina, CN2, optic chiasm, optic tract, CN3; subcortical reflex does not equal vision

Quiet; overhear light; bright for distant exam; dim for close inspection; dark for patients w/ severe corneal opacity

Schirmer tear test; tonometry

Normal >15mm/min; Suspicious 10-15mm/min; Affected <10mm/min

Clarity and position

Specify ophthalmic drug panel for sensitivity testing

Pupillary dilation recommended; contraindicagted in glaucoma, lens instability

Water soluble dye repelled by intact epithelium

What is being shown?

Normal IOP 9-31 mmHg in cats; <20% variation between eyes

Part of neuro-ophtho exam; cortically mediated learned response; check each eye separately; avoid air currents

Assesses retina, optic nerve, optic radiations, visual cortex, CN VII

Symmetry; mental state; gross changes: discharge, discomfort, opacity

Decreased in excited animals; Iris atrophy causes decreased/absent - older animals, commonly overlooked

Essential for a complete fundoscopic exam

1% tropicamide; 0.5% proparacaine

Gather cells w/ spatula, brush or blunt end of scalpel blade; gently transfer cells to slide and stain

Palpebral reflex; menace; direct + consensual PLR; dazzle reflex; Schirmer tear test; Fluorescein dye test; tonometry

Penlight; otoscope; finoff transilluminator: halogen light, focused beam, variable intensity, rechargeable

Measurement of intraocular pressure; Types: Schiotz Tonometer, Tonopen, Tonovet; Normal IOP 8-25 mmHg in dogs

Posterior portion of eye examined w/ ophthalmoscope; composite structure: retina, choroid/tapetum, sclera, optic disc

What is being shown?

Be prepared; better equipment = better exam; practice, practice, practice

Bright light elicits rapid eye blink; requires functional retinal photoreceptors, optic nerve (to midbrain level)

Look for speed of navigation; object avoidance

Lid conformation; extra lashes; tumors

Indicated in patients with dull cornea, sticky discharge; performed prior to any topical therapy

Indicated inpainful eyes and those w/ cloudy corneas; detects corneal epithelial defects

Microtip culturette; prior application of topical anesthetic does not significantly alter results

Prominent nictitans; altered IOP/STT; Miosis