Exam 5 (eye)

OD Oculus dexter
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Terms in this set (93)
OD Oculus dexter
right eye
OS Oculus sinister
left eye
OU Oculi uterque
both eyes
enclosed bony orbit
cows, sheep, horses, goats, and primates have a:
open bony orbit
pigs and carnivores (ie dogs and cats) have a:
Supraorbital ligament
what closes a pig, dog, or cat's orbit: frontal to zygomatic bone
Oculomotor (CN III)
Dorsal (superior) rectus, ventral (inferior) rectus, medial
rectus, and ventral (inferior) oblique muscles
Trochlear (CN IV)
Dorsal (superior) oblique muscle
Abducens (CN VI)
Retractor bulbi muscle, lateral rectus
optic nerve
located ventral/lateral from midline
Trochlear (CN IV)Dorsal (superior) oblique muscle (________) intorsion of globeOculomotor (CN III)Ventral (inferior) oblique muscle (________) extorsion of globeLevator palpebrae superioris muscleInnervated by CN III --> Elevates upper eyelidOrbicularis oculi muscleInnervated by CN VII --> Blink eyelidMueller's muscleSmooth muscle - Sympathetic tone Widens palpebral fissure --> Elevates upper eyelid, Depresses lower eyelids, Horner's syndrome loss of sympathetic innervationOrbital lacrimal gland~60-70% of aqueous tear fluid • Superior-temporal orbitGland of the 3rd eyelid glandBase of 3rd eyelid • ~ 30-40% of aqueous tear fluidNasolacrimal Systemin charge of draining tears --> canaliculi--> sac --> duct --> nose or mouthPalpebral conjunctivaLines inner surface of eyelidsBulbar conjunctivaCovers surface of globeTrueT/F: If you have a tumor of the Choriod, everything is attached so it may affect the irisFalseT/F: layers of the cornea --> in order: Epithelium --> Descemet's membrane --> Stroma --> EndotheliumFalseT/F: There are no nerves or vessels within the corneaTrueT/F: DM and age can cause the cornea to be less sensitiveCorneal EpitheliumNonkeratinized stratified squamous epithelium that is lipophilic (ie won't retain stain)Descemet's membranebasement membrane of corneal endothelium, lipophillicCorneal Endotheliumsingle layer, poor regeneration, almost all waterTrueT/F: stain will only retain in the stroma of the eyeLimbusCorneoscleral junction, Variably pigmentedLamina cribosaOptic nerve passes through sclera --> area of weaknessIriscontains a sphincter and dilator muscle (smooth muscle in mammals), parasympathetic and sympathetic innervationPars plicata - Ciliary BodyProduction of aqueous humor by nonpigmented ciliary body epitheliumZonules - Ciliary BodyAttach ciliary body process to the equator of the lens --> suspends lensPosterior chamberbetween iris and lensFelinesome glaucoma drugs are not as helpful in ____, due to the minimal variations of Aqueous Humor OutflowChoriocapillarisMain source of nutrition for outer layers of retina/Posterior UveaTapetum LucidumReflective layer in the inner choroid on dorsal fundus pro: better night vision con: worse day visionRodson retina --> shapes and motion/dim lightConeson retina --> color/daylightFalseT/F: Most species we work with will be cone dominantConesa fovea is a ____ rich areaRetinal detachmentsPotential space between RPE and photoreceptors --> area ofHolangiotic Vascular Patterndog, cat, rat, and cow have:Merangiotic Vascular Patternrabbits have: (medially and laterally)Paurangiotic Vascular Patternequine have: (small, few mm out)Anangiotic Vascular Patternbirds have:FalseT/F: The lens nucleus gets more flimsy with ageTrueT/F: TX of high Vitreous Humor would be drugs such as mannitol that will dehydrate the eye and the whole bodyVitreous HumorTransparent, jellylike material --> Transmit light, Maintain the normal retinal positionTrueT/F: Cats have less myelin so they will have a more gray looking optic nerve than dogsMerle ocular dysgenesisthis is a case ofFinoff transilluminatorProparacaineeye anestheticTropicamidecauses mydriasis, used in retinal examsMenace ResponseCover opposite eye, Don't touch facial hairs, Learned response (~4 months+)Menace ResponseStimulus: Motion Receptor: Retina Afferent: Optic nerve (II) Efferent: Facial nerve (VII) Effector: Orbicularis oculiPupillary Light Reflex (PLR)Stimulus: Light Receptor: Retina Afferent: Optic nerve (II) Efferent: Oculomotor (III) Effector: Iris sphincter musclePupillary Light Reflex (PLR)Direct PLR, Indirect or consensual PLR, ParasympatheticFalseT/F: PLR = VisionPalpebral/corneal ReflexesStimulus: Touch Receptor: Skin/cornea Afferent: Trigeminal nerve (V) Efferent: Facial nerve (VII) Effector: Orbicularis oculi *should only do if you think is abnormalDazzle Reflex*only do if blind, bright light blink response, not same as vision, no need to test if penance is positiveDazzle ReflexStimulus: Bright light Receptor: Retina Afferent: Optic nerve (II) Interneuron: CNS/subcortical Efferent: Facial nerve (VII) Effector: Orbicularis oculi muscleTrueT/F: you should be able to Retropulse globe of lab more than with a pugTrueT/F: You should do an oral exam as well because there can be pain opening the mouth if there is orbital diseaselagophthalmosinability to close eye(s)third eyelidApply topical anesthetic, grasp with a forceps and evert or pull forward with cotton tipped swab --> look for FB behind __________ConjunctivaEvaluate bulbar and palpebral surfaces for injected vessels, bleeding, swelling, masses, foreign bodies, etc.ScleraShould be white, Evaluate for episcleral vessel congestion, masses, etc.RedYou see ____ in the eyes with vesselsWhiteYou see ____ in the eyes with scars, WBCs, lipids, and calciumBlueYou see ____ in the eyes with edemaBrownYou see ____ in the eyes with pigment and FBsHyphemaBlood in anterior chamberHypopyonWBC in anterior chamberdyscoriaAbnormal shape pupilsanisocoriadifferent size pupilsAtropinedilates the pupil, but not used in retinal exams due to it's long durationDirect ophthalmoscopytype of examIndirect ophthalmoscopyIndirect ophthalmoscopyUpside down and backwards Lower magnification Binocular or monocular view Larger field of view Higher diopter lower magnification Lower diopter higher magnificationDirect ophthalmoscopyReal, upright image Higher magnification Monocular view Small field of view Useful for close examination of optic nerve/retinal lesionsFalseT/F: Bacteria can frequently be cultured at low numbers from NORMAL conjunctiva. Staphylococcus spp, Streptococcus spp, Cornyebacterium, and Bacillus spp at any time will mean infectionFalseT/F: Kimura platinum spatula, blade of surgical blade, cytobrush, and cotton swabs are used to take cytology samplesSchirmer Tear Test (STT)Measures aqueous component (basal and reflex tears) in dogs --> do prior to topical anestheticSchirmer Tear Test (STT)Normal >15 mm/min (dog)Fluorescein Stainused in Corneal ulcer (touch white part of eye), Jones test, Tear film break up time, Seidel testJones TestEvaluates patency of nasolacrimal system (normal passage time < 5 min)Tear Film Break-Up Timeuse stain --> do not rinse --> should take over 20 seconds before stain goes away too quick --> dry eyeSeidel TestAqueous humor leakage --> Corneal lacerations, Ruptured ulcers, Surgical incisionsTonometryMeasures intraocular pressureTrueT/F: Normal intraocular pressure = 15-25 mmHg, always believe lowest readingTrueT/F: Tono Pen® requires topical anesthetic while Tonovet ® does ntNasolacrimal Flushdone if there is a blockage of puncta --> flush Flush saline from superior to inferior puncta, then occlude inferior puncta with digital pressure and flush into the nasal cavity *not routinely done, only if you think there is a blockage