OPTHALMOLOGY 1 Flashcards
Is the canine orbit open or closed? What does that mean?
open: Incomplete in the
temporal or dorsal
region, continuous with the
temporal fossa
The canine orbit is divided into the intraconal and extraconal space. What is in the intraconal space?
extraocular muscles, CNII, III, IV, V(1), VI)
The canine orbit is divided into the intraconal and extraconal space. What is in the extraconal space?
neurovascular structures, nictitating membrane, zygomatic salivary gland
What is exophthalmos?
Protrusion of a normal-sized globe.
[really need to look from above the dog to see]
What are the clinical signs of orbital disease?
*Exophthalmos,
*increased resistance to digital retropulsion,
*strabismus,
*pain when opening the mouth, *third eyelid protrusion,
*periocular swelling, *lagophthalmos,
exposure keratopathy, *conjunctival hyperemia, chemosis, congestion.
What si strabismus?
eye going in a different direction
What are common causes of exophthalmos?
- Retrobulbar cellulitis/abscess
- Retrobulbar neoplasia
What are less common causes of exophthalmos?
- Myositis of masticatory or extraocular muscles
- Adenitis of the zygomatic salivary gland (sialoadenitis)
*Retrobulbar haemorrhage - Cystic space occupying lesions of the nictitans gland or zygomatic mucocoele
- Dacryops
- Dermoid cyst
What is lagopthalamos?
inability to blink/close eyes
What is dacryops?
fluid-filled cyst in lacrimal gland
where will a retrobulbular abscess be located?
periorbital space:
-peridontal/endodontal
-sinusitis
-sialoadenitis
-panopthalmitis
What are the 3 different aetiologies of retrobulbar abscess/cellulitis?
infectious or inflammatory:
*contagious periorbital structures/spaces
*direct inoculation/infection
*secondary orbital foreign bodies
these are clinical signs of what?:
*Acute presentation/rapid progression
*pain when opening the mouth,
* pyrexia, anorexia, neutrophilia with left shift
retrobullbular cellulitis
What are 4 diagnostic techniques for retrobulbar abscess/cellulitis?
*investigation
*orbital ultrasonography
*radiographs:
*examination of oral cavity
During diagnosis for retrobulbar cellulitis/abscess, what are you looking for during radigraphy?
during examination of the oral cavity?
rads: caudal maxillary molar tooth to assess for peridontal disease
oral cavity: pterygopalatine fossa n maxillary molar teeth
What initial management should be provided for retrobulbar cellulitis/abscess without an abscess or foreign body?
Broad-spectrum antibiotics (4 weeks) and NSAIDs.
[can do amoxy-clav or cephalosporins]
Why are retrobulbular abscess/cellulitis treated as an emergency?
direct communication btwn orbit and CNS
[optic nerve is surrounded by meninges]
What is the prognosis for retrobulbar abscess with proper treatment?
Generally good with proper antibiotic therapy and drainage.
What are the signs of retrobulbar neoplasia in dogs?
*Slowly progressive
*painless exophthalmos, *strabismus,
* third eyelid protrusion w/o pain with mouth opening or palpation.
What percentage of retrobulbular neoplasia are malignant?
90%
Retrobulbular neoplasia generally affects which age group?
> 8 y/o
What si the most common tpye fo retrobulbular neoplasia?
retrobulbular adenocarcinoma
In an exam for retrobulbular neoplasia, air flow should be examined where?
air flow in the nostril of affected side
What is the mean age of dogs affected by masticatory myositis?
3 years.
