Orbital Disease in Small Animals Flashcards
what is exophthalmos?
rostral deviation of the globe
what can cause enophthalmos?
loss/shrinkage of orbital contents
rostral orbital disease
what are conjunctival changes often due to?
vascular stasis/congestion
what is a major cause of pain with ocular disease?
impingement by mandibular ramus
what is CT excellent for?
bone
teeth
adjacent structures
what is MRI excellent for?
soft tissue
CNS
in who are abscesses/cellulitis fairly common?
dogs
how long should you treat an abscess/cellulitis?
minimum of 6 weeks
when should you consider fungal disease?
travel history
no response to antibiotic therapy
which breeds can get masticatory myositis?
german shepherds
weimaraners
cavaliers
viszlas
how can you diagnose masticatory myositis?
serology +/- muscle biopsy
what are late effects of radiation to the eye?
permanent KCS
cataracts
retinal degeneration
who is proptosis common in?
brachycephalics
what percentage of animals with proptosis will retain vision?
10-20%
when might an orbitotomy be performed?
localized tumor
foreign body
walled-off infection
what glands are in the orbit or neighboring it?
lacrimal gland
zygomatic salivary gland
third eyelid
in whom is exophthalmos normal?
brachycephalics
what is enophthalmos?
loss/shrinkage of orbital contents
usually with third eyelid protrusion
is elevation of the third eyelid a nonspecific sign of pain?
yes
what can you give for pain management in orbital disease?
ideally NSAID with some caveats
+/- opioid, gabapentin, tramadol
what is ultrasound good for?
soft tissue, poor for bone
biopsies, aspirates, drain fluid
what are some infectious etiologies of orbital disease?
abscesses
cellulitis
why might an animal with an abscess or cellulitis be blind?
optic nerve compression
should you poke behind the last molar for abscess/cellulitis?
no
what are some antibiotic combinations good for abscesses/cellulitis?
clindamycin and baytril
baytril and metronidazole
clavamox and baytril
what should you consider if an abscess or cellulitis is having inadequate response to treatment?
foreign body
dental disease
fungal disease
noninfectious causes: lymphoma
what parasites can cause orbital disease?
Taenia/cysticercosis: rabbit/chinchilla
Toxocara canis
Onchocerca spp
Toxoplasma gondii
Neospora caninum
Leishmania
Ehrlichia canis
what is an orbitotomy?
surgical entry into orbit
what is the acute phase of masticatory myositis like?
palpable swelling of muscles
pain +/- fever
eosinophilia or neutrophilia
variable exophthalmia
how can you treat masticatory myositis?
immunosuppressives long term: start with prednisone
who usually gets extraocular myositis?
young dogs
retrievers overrepresented
how can you treat extraocular myositis?
usually responds well to immunosuppression
what neoplasias can be primary orbital tumors?
meningioma
sarcomas
what is exenteration?
removal of entire orbital contents including globe
what are acute phase effects of radiation to the eye?
decreased tear production
keratitis
conjunctivitis
moist desquamation of skin
when should you enucleate an proptosed eye?
globe ruptured
hyphema
>2 extraocular muscles ruptured
extensive conjunctival rupture
what is evisceration?
removal of intraocular contents, retaining sclerocorneal shell
silicone intrascleral prosthesis placed
what is exenteration?
removal of globe and orbital contents
what is an orbitectomy?
resection of orbit in its entirety including bony walls
