Ear & Eye Flashcards
What are the 3 ossicles from lateral to medial?
a. Malleus: comma shaped
b. Incus: within epitympanic recess
c. Stapes: separates tympanic cavity from perilymphatic space
Describe path of facial nerve in relation to ear canal
Motor innervation
Through internal acoustic meatus > through fascial canal of petrons temporal bone > exists stylomastoid foramen (caudodorsal osseous ear canal) *caudomedial to bulla * > crosses ventral horizonal ear canal»_space; palpebral branch or lingual branch
What nerve is sensory to ear canal?
Vagus n.
What are the names of the margins / cartilages around the external ear canal opening?
a. Cranial: helix
b. Medial: Antehelix
c. Caudal: Antitragus
d. Lateral: Tragus
Where are the 5 major described vessels located associated with ear canal?
a. Great auricular a. > overlies vertical portion (medial to dorsal apex of parotid gland)
b. Maxillary v. + external carotid > ventral to tympanic bulla
c. Retroglenoid v > rostral to osseous ear canal
d. Internal carotid a > medial to bulla
Simplified, describe hearing and balance
a. Hearing: sound waves hit tympanic membrane > [x] by ossicles > + movement of endolymph within cochlea > converted to nerve impulse by organ of Corti > brain via cochlear n.
b. Balance: fluid movement within vestibule and semicircular canals > hair cells (maculae) and detection depends on canal, otoliths of saccule, and utricle
What are 3 parts of inner ear?
a. Vestibule > middle, contains saccule + utricle
b. Cochlea > seashell contains organ of Corti
c. Semicircular canals > 3 (anterior, lateral, posterior)
What is the vascular supply to middle ear? Nerve supply to inner ear?
a. Tympanic a (from maxillary a) + meningeal + pharyngeal vessels
b. Vestibulocochlear > vestibular > semicircular canals > cochlear n > Organ of Corti
What are 3 components of tympanic cavity called and what do they contain?
a. Dorsal: epitympanum (epitmpanic recess), incus, and part of malleus
b. Middle: mesotympanum – 2 membranes covering middle ear chamber, manubrium of malleus, eustachian tube, bone promontory
c. Ventral: hypotympanum – longest, within bulla > communicates with the tympanic cavity proper
- What can actinic keratosis turn into? Which breed or type of cat most likely gets it?
- Treatment for it?
- What is most common feline cutaneous neoplasm?
- Which breeds predisposed?
- List tx options of SCC of ear in cats?
- SCC - white cats
- Pinnectomy or laser surgery; sunblock preventative?
- Basal cell tumor
- Siamese, Himalayan, Persion
- Partial or total pinnectomy; cryosurgery; laser ablation; pinnectomy + vertical canal ablation; radiation; chemotherapy
- Most common cause of para-aural abscess? % incidence?
- Tympanic membrane can be intact up to __% ears with otitis media?
- List radiographic views to evaluate ear.
- Incomplete debridement of epithelial lining of TECA –> 6-11% dogs with TECA
- 71%
- Lateral;
Dorsoventral or ventrodorsal;
Latero 20 deg ventral -laterodorsal oblique;
Rostro 30 deg ventral - caudodorsal open mouth oblique
- List tx options of auricular hematoma
- With cryotherapy, what is recommended # of cycles for max tumor destruction?
- Repeated needle aspirates
Passive drainage
Active drainage
Chronic hematoma - S drainage incision + stures
CO2 laser drainage / ablation
Human fibrin sealant
Drainage + methylprednisolone into cavity w/ or w/o oral systemic steroids - Two
- What % cats have facial palsy pre-op TECA?
- What % have post-op facial n deficits w/ TECA for dog and cat & what % is permanent?
- % risk for hemorrhage? Which vessel usually?
- % cases that get dehiscence?
- What is failure rate of lateral wall resection?
- 8% pre-op cats
- Post-op
Dogs: 13-39% ; permanent 4-13%
Cats: 12-56% ; permanent 28% - 3-14% hemorrhage; retroglenoid v.
- 25% dehiscence
- 42-55% failure rate
- With pinna SCC in cats, what % recur w/ cryotherapy & what is DFI?
- With grade 3 MCT of ear, what is median DFI w/ pinnectomy?
- With complete excision, what is DFI & MST for feline pinna SCC?
- For aural ACA, what is MST if within ear canal vs extensive involvement after surgery?
- 73%; DFI ~184 days
- 5 months
- DFI 19-22 months; MST 800 days
- Extensive involvement: 5 months
Excision and within canal: 30 months
- List 3 routes of middle ear bacteria
- What are the most common organisms causing otitis media?
- List Ddx for tumors of tympanic membrane
- What breed often gets secretory (serous) otitis media?
- External auditory meatus via tympanic membrane
Nasopharynx via auditory tube
Hematogenous - Staph intermedius
Malassezia
Pseudomonas - Ceruminous gland ACA
SCC
Carcinoma
Lymphoma - Cavalier King Charles Spaniels
- List 3 congenital anomalies of inner ear leading to loss of hearing / balance & their associated breeds
- What view is best in cats to look at bullae?
- List 3 alternative diagnostic tools to evaluate middle / inner ear (not the usual tests)
- Collapse of scala media - Dalmatian
Neuroepithelial degeneration - Rottweilers
Changes in organ of Corti - Pointers - 10 deg ventrocaudodorsal view
- CSF
Brainstem Auditory Evoked Responses (BAER)
Impedance Audiometry
- What is recurrence rate of non-endoscopic traction vs endoscopic transtympanic + curettage + steroid (all endoscopic) for polyps?
- What are options (less invasive) for managing middle ear drainage dysfunction?
- Bullae located / bordered by what for VBO surgical approach in cats?
- Prognosis for cholesteatoma?
- 57% vs 13.5% !
- Myringotomy
Tympanostomy tube or “grommets” - Mandibular symphysis
Caudal mandible
Larynx - Guarded - 45-50% recurrence
- What drug can help tx pain after corneal procedures by decreasing ciliary spasm?
- List types of eyelid speculums
- What muscles elevate superior eyelid?
- What muscle lowers inferior eyelid?
- Cycloplegics (atropine)
- Lightweight Barraquer Wire Speculum
Self-retaining Castroviejo speculum - Levator anguli oculi medialis, levator palpebrae superioris, Müller’s, frontalis
- Malaris muscle
- What are 3 causes of ectropion?
- What is general idea of treatment for each?
- What is Euryblepharon?
Breeds seen often?
Treatment?
1 and 2. Excessively long palpebral fissure –> shorten eyelid
Contraction of scar tissue from previous laceration –> V to Y blepharoplasty
Overcorrection from entropion surgery –> V to Y blepharoplasty
3. Enlargement of palpebral aperture secondary to longer eyelids
– Neopolitan mastiffs, Bloodhounds, Newfies, Clumber spaniels
– Pocket technique for permanent medial canthoplasty
- List tx of distichia
- What are the temperatures to avoid with cryo?
- List Ddx of eyelid tumors in dogs. What is most common in dogs? Cats?
- What is it called to have enlargement of Meibomian gland from intraglandular accumulation of meibum secondary to duct obstruction?
- Cryoepilation
Electroepilation - Below −30°C
- Dogs: Meibomian glands (most common), melanomas, squamous papilloma, histiocytoma
Cats: most common - SCC - Chalazion
- What are treatment options for nasolacrimal duct?
- Treatment for tear film deficiency?
- What are the 5 forms of conjunctiva?
- Nasolacrimal flushes and systemic / topical abx therapy
Catheterization conservative flushing
Exploratory dacryocystotomy
Conjunctivorhinostomy - Immunosuppressives (cyclosporine or tacrolimus)
Parotid duct transposition - Palpebral conjunctiva
Conjunctiva of bulgar and palpebral sides of nictitans
Bulbar conjunctiva
Conjunctival fornix
- List types of nonneoplastic conjunctival masses.
- List Ddx feline conjunctival neoplasia
- Dermoid
Subconjunctival prolapse orbital fat
Onchocerciasis
FBs
Nodular granulomatous episcleritis
Conjunctival cyst
Fibrous histocytoma
Nodular fascititis
- List predisposing factors to get otitis externa
a. Pendulous ears (Spaniel)
b. Narrow ear canals (Shar peis)
c. Hair growth in canal (Poodles)
d. Excess cerumen (Cockers)
e. Chronic ear moisture (bathing/ swimming)
f. Inappropriate abx use, polyp, or tumor in external ear
What is most significant perpetuating factor of otitis/ externa/media?
a. Proliferation and overcolonization of bacteria
List pathologic bacteria of ear canal
a. Staph intermedius, Staph pseudintermedius, pseudomonas, proteus, E coli, Corynebacterium, enterococcus, streptococcus
List Ddx of malignant external ear canal masses
a. Ceruminous carcinoma
b. SCC
c. Plasmacytoma
d. Anaplastic carcinoma
e. STS
f. Melanoma
What breed predisposed to ceruminous ACA?
a. Cocker Spaniels
What % of ear canal tumors malignant?
a. 60%
List tx options of traumatic separation of annular / auricular cartilage junction described in dogs/cats
a. TECA-BO
b. Horizontal ear ablation & lateral bulla osteotomy + preserve vertical canal
c. Primary repair – caudal approach
With lateral wall resection; recurrence of clinical signs for otitis media / externa?
a. 11%
What is concern for brachycephalic breeds and TECA-BO approach?
a. Majority bullae medial to mandible – so lateral approach tough
Lavage of ear canal decreases positive culture by __%?
33%
Horner’s post-op TECA in cats? What % permanent? What % have it pre-op?
a. 6% pre-op; 27-42% post-op; 14-27% permanent
What is ankyloblepharon?
a. Delayed opening of eyelid
List types of entropion
a. Conformational
b. Cicatrical
c. Involutional
d. Spastic
List options to treat entropion
a. Temporary correction - vertical mattress
b. Permanent:
i. Hotz-Celsus
ii. “Stades” procedure modification (upper eyelid)
iii. Modified Kubut-Szymanouski
List reconstructive strategies for large eyelid defects
a. Sliding pedicle advancement flap
b. Myocutaneous pedicle graft
c. Semicircular flap
d. Lip to lid flap
What are 3 components of tear film & where produced?
a. Aqueous – by lacrimal gland (thickness)
b. Mucin – globlet cells in conjuction (innermost)
c. Lipid – Meibomian glands (outermost)
What is a Dacryops?
a. Lacrimal cysts in dorsolateral conjunctival area of globe or mass between medial canthus & third eyelid
List options for surgical tx of prolapse of nictitating membrane gland?
a. Orbital rim anchoring technique OR Morgan pocket technique
What breed has inheritability of everted nictitating membrane
a. German Shorthaired Pointer
What is a plasmoma and what breed is predisposed?
a. Nodular or diffuse thickening of nictitating membrane; GSD most
What are disadvantages of Nictitating membrane flaps?
a. Obscure visualization of cornea
b. No blood supply
c. Less support than conjunctival pedicle graft
d. Inhibits topical meds from access
What are 3 types of ways to perform keratotomy?
a. Grid – 25 gauge needle
b. Punctate
c. Battery powered – hand-held diamond burr
When in cats do you not do keratotomy?
a. Cats with indolent ulcers – increases sequestra formation
What breed commonly gets Indolent ulcers
Boxers
If keratectomy is deeper than ___ corneal thickness – pedicle graft placed
a. Half
List approaches to orbit
a. Modified orbitotomy (lateral)
b. Anterior or dorsal orbitotomy
c. Transoral orbitotomy
d. Orbitectomy
List 2 types of enucleation approaches
a. Subconjunctival approach
b. Transpalpebral approach
List types of conjunctival grafts
a. Pedicle graft
b. Bridge graft
c. Island graft
d. 360 deg graft
Corneoconjunctival transposition – which types of lesions best used for?
a. Axial lesions <= 5 mm
What are extracellular matrix graft examples for corneal defects?
a. Porcine small intestinal submucosa or porcine urinary bladder
Phacoemulsification is great for which lens issues but not great for which?
a. Great: unstable lens with zonal integrity
b. Not great: complete luxation
List surgical treatment for glaucoma
a. Temporary keratostomy (IOP decreased)
b. Gonioimplantation
c. Cyclophotoablation
