Medicine I > Orbit > Flashcards

Orbit Flashcards

(48 cards)

Study These Flashcards
1
Q

What is the function of the orbit?

A
  • Protect the globe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What structures are part of the orbit?

A
  • Nerves and blood vessels
  • Extraocular muscles and Orbital fat
  • Third eyelid
  • Lacrimal gland
  • Muscles of mastication, zygomatic salivary gland, medial pterygoid muscle
  • Skull bones - open or closed orbit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the parts of an Orbital Exam?

A
  • Visual inspection
    • Symmetry
    • position of third eyelid
    • Position and motility of globe
  • Palpation of orbital rim
  • Retropulsion of globes
  • Vision and PLR assessment
  • Nasal air flow
  • Ability/extent of mouth opening
  • Oral exam
    • caudal to last upper molar
    • sedation/general anesthesia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the clinical signs of orbital disease?

A
  • Exophthalmos
  • Enophthalmos
  • Strabismus
  • Elevated third eyelid
  • Pain on palpation of periorbital area
  • Pain on opening mouth
  • Exposure keratitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Exophthalmos?

A
  • Normal sized globe displaced anteriorly/rostrally within the orbit
  • Due to increased orbital volume
  • Numerous causes
    • Neoplasia, abscess/cellulitis, hemorrhage, vascular anomaly, mucocele, cysts, myositis, etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is enophthalmos?

A
  • Normal sized globe displaced posteriorly/caudally within the orbit
  • Due to globe retraction, decreased orbital volume or pressure anterior to the equator of the gobe
  • Numerous causes
    • Pain, msucle wasting, loss of orbital fat, Horner’s syndrome, orbital fractures, dehydration, extraocular muscle fibrosis, adnexal neoplasia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Microphthalmos?

A
  • Congenitally small globe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Phthisis bulbi?

A
  • Shrunken globe
    • post inflammatory change
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What diagnostic tests can be done for orbital diseases?

A
  • Minimum database
  • Imaging studies:
    • skull radiographs
    • Dental Radiographs
    • Orbital/ocular ultrasound
    • Computed tomography (CT)
    • Magnetic resonance imaging (MRI)
  • Orbital sampling
    • FNA and cytology
    • Culture and sensitivity
    • Biopsy and histopathology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How useful are Skull Radiographs in diagnosing orbital disease

A
  • Difficult to interpret
  • Useful for:
    • Bony lysis or proliferation
    • Sinus or nasal disease
    • Radio dense foreign bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How useful are dental Radiographs in diagnosing orbital disease

A
  • Useful when suspecting dental disease that is infiltrating into the orbit
    • i.e. tooth root abscess
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How useful is Ultrasound in diagnosing Orbital disease?

A
  • Needs Topical anesthetic
  • Ocular ultrasound - 10-13 MHz probe
  • Orbital Ultrasound - 7.5 MHz probe, Doppler
  • Useful for:
    • Cysts and abscesses
    • Vascular anomalies
    • Foreign bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How useful is CT in diagnosing orbital disease?

A
  • Requires general anesthesia
  • Useful for:
    • 3D orbital imaaging
    • Examination of boney details
      • orbital fractures
      • bony lysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How useful are MRIs in diagnosing orbital disease?

A
  • Requires general anesthesia
  • Useful for:
    • 3D orbital imaging
    • Detailed soft tissue study
  • Contraindicated with metallic foreign bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can Samples be taken from the orbit?

A
  • Fine needle aspirate or biopsy
  • Can perform “blind” or w/ ultrasound/CT guidance
  • Many important structures!
  • Approaches:
    • Transconjunctival adjacent to the globe
    • Through skin posterior to orbital ligament
    • Oral
      • Caudal to last molar tooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are some common Orbital abnormalities and diseases?

A
  • Congenital abnormalities
  • Orbital cellulitis/abscess
  • Salivary mucocele or cysts
  • Masticatory muscle myositis
  • Orbital neoplasia
  • Ocular proptosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are common congenital abnormalities of the orbit?

A
  • Microphthalmos
  • Divergent strabismus
    • Exotropia
    • mainly brachycephalic dogs
    • usually no clinical significance
  • Convergent Strabismus
    • Esotropia
    • Inherited in cats
      • Autosomal recessive
      • primarily in Siamese
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Orbital Cellulitis/Abscess? Who commonly is affected

A
  • Inflammation of the orbital tissues +/- abscess
  • Common Presenting Signalment and History:
    • Young animal
    • acute onset
    • compatible history (I.e. Stick chewing)
    • Possibly hyporexic or decreased chewing/aversion to hard food
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the Clinical signs and findings

A
  • Exophthalmos +/- lagophthalmos
  • Elevated third eyelid
  • Injected conjunctival and episcleral vessels
  • Resistant to retropulsion +/- pain
  • Pain on periorbital palpations
    • Yelps when mouth opened
  • Febrile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are common findings in an oral exam of a patient with orbital cellulitis/abscess

Study These Flashcards
A
  • Swelling +/- fistula caudal to last upper molar tooth
    • pterygopalatine fossa
21
Q

What is the treatment for Orbital Abscesses

Study These Flashcards
A
  • Confirm abscess (imaging)
  • Establish drainage if accessible
    • incise oral mucosa caudal to last upper molar w/ #15 blade
    • Insert closed hemostat, advance slowly, then open
    • Collect samples
      • culture/sensitivity (aerobic & anaerobic) and cytology
    • Leave open to drain
      • may not see a lot of drainage
  • Remove nidus, if present
  • Medical therapy
    • Systemic antibiotics (often mixed aerobic & anaerobic)
      • Cephalosporines (cepfodoxime, Clavamox) & Enrofloxacin are good first choices
    • Systemic NSAID for pain and inflammation
    • Ocular lubrication
      • Can use broad spectrum antibiotic ointment
      • temporary tarsorrhaphy
    • Soft food
  • Response to therapy is usually w/in 2-3 days
  • Prognosis is good
22
Q

Why would a salivary mucocele/cyst affect the orbit?

Study These Flashcards
A
  • Usually due to trauma
  • Saliva leaks from zygomatic salivary gland, causing inflammation and tissue fibrosis
    • Results in an encapsulated ‘cyst’
23
Q

What are the signs of an orbital salivary mucocele/cyst

Study These Flashcards
A
  • Exophthalmos and 3rd eyelid elevation
  • No/minimal pain
24
Q

How are abscesses/neoplasias distinguished from salivary mucocele/cyst in the orbit?

Study These Flashcards
A
  • imaging and sample collection
    • aspiration of yellow, tenacious fluid
25
what is the treatment for a salivary mucocele/cyst in the orbit
* Surgical excision or drainage * some reports of sclerosing agent injection
26
What is Masticatory Muscle myositis?
* Immune-mediated inflammation targeting temporalis, masseter, and pterygoid muscles * Type 2M myofibers * Breed predisposition * Golden and Labrador Retrievers * German Shepherds * Weimeraners
27
what are the clinical signs of Masticatory Muscle Myositis?
* Acute onset bilateral exophthalmos * painful and restrictive jaw movements * fever * lethargy * anorexia
28
How is Masticatory Muscle Myositis diagnosed
* 2M antibody test * compatible clinical signs
29
How is Masticatory Muscle Myositis diagnosed
* Systemic immunosuppression
30
Where do orbital neolasias originate from?
* Primary from any orbital tissue * Invasion from adjacent structures * Metastasize from distant site
31
What are the clinical findings with Orbital Neoplasia
* Unilateral exophthalmos * Elevated third eyelid * Decreased retropulsion * Scleral indentation on fundic exam * Usually Not Painful
32
How are Orbital Neoplasias diagnosed?
* Complete physical exam * Thoracic radiographs (metastasis) * Orbital ultrasound * CT/MRI for lesion localization and surgical planning * FNA/biopsy of lesions
33
What is the treatment for orbital neoplasias?
* Orbitotomy and mass excision (referral) * Exenteration or radical orbitectomy * +/- radiation therapy and/or chemotherapy * Enucleation or exenteration may also be performed as a palliative measure * Euthanasia if advanced disease
34
What is the prognosis of orbital neoplasia
* Guarded to poor * Survival time increases w/ early diagnosis and surgical therapy * \<1yr in dogs * ~1mo in cats
35
What is Ocular Proptosis
* Globe moves anteriorly and eyelids become “trapped" behind equator * True ophthalmic emergency
36
What causes Ocular Proptosis?
* Caused by trauma * Hit By Car, dog fight, kicked by horse * Degree of trauma needed varies: * Most common in brachycephalic dogs * shallow orbit and large palpebral fissure * Minimal trauma needed * Prognosis very poor in horses, cats, and dolicocephalic dogs * severe trauma necessary
37
How is Ocular Proptosis managed?
* Ocular lubricant & E-collar * KY Jelly, artificial tears, eyewash, Vaseline, cooking oil, etc * Complete physical exam - assess for other injuries * Complete eye exam * Decide whether to enucleate or surgically reposition eye * 3 enucleation criteria: * 3 or more EOMs torn * Optic nerve transected * Globe (cornea and/or sclera) ruptured
38
How is the globe prepped for surgery following Ocular Proptosis?
* Keep eye lubricated * Carefully clip eyelid hair * Cleanse area with dilute betadine solution * ~1:50 dilution * 5ml 5% betadine in 250 ml saline * **NOT** betadine scrub or chlorhexidine - toxic to cornea
39
What is the treatment for Ocular Proptosis following surgery?
* Medications: * oral antibiotic * Oral NSAID * Topical antibiotic * Topical atropine * Pain meds as needed * E-collar * Keep area clean * Rechecks * Remove sutures in 2-3 wks * staged removal may be necessary
40
What is the Prognosis following Ocular Proptosis?
* Good - brachycephalic and minor trauma * Guarded for vision w/ intraocular hemorrhage * Pupil size is not an indicator of prognosis * is Direct or consensual PLR present - prognosis is good * Vision prognosis varies (~20% have some vision)
41
What are possible complications of Ocular Proptosis?
* Blindness * Strabismus * Primarily lateral strabismus * Lagophthalmus ⇢ exposure keratitis * Decreased corneal sensation * Keratoconjunctivitis sicca (dry eye disease) * Glaucoma or phthisis bulbi (severe intraocular damage)
42
What is enucleation surgery?
* Surgical removal of globe, third eyelid & gland * +/- silicone orbital prosthesis
43
What is orbital evisceration surgery?
* Removal of intraocular contents and placement of a silicone prosthesis in corneo-scleral shell * Contraindicated in cases of neoplasia or infectious intraocular disease process * Not recommended in cats - increased implant extrusion risk
44
What is orbital exteneration surgery?
* Removal of globe and all orbital soft tissues * transpalpebral approach * Routine skin closure * Generally performed for orbital neoplasia * Submit tissue for hitopathology
45
What are the different surgical approaches for Enucleation surgery?
* Transconjunctival Enucleation * Widen lateral canthus * Remove eyeball and nictitating membrane * incise eyelids and suture closed * Transpalpebral Approach * indications: surface ocular infection or neoplasia * Suture eyelids closed * Incise skin around lids and dissect down to sclera, then work posterior
46
What is the post-operative care for Enucleation surgery
* Cold compress (BID - TID for 10-15 minutes if tolerated) * Some bleeding from incision and ipsilateral nostril is expected * Systemic nonsteroidal anti-inflammatory drug and/or other analgesic medication * E-collar if needed * Suture removal in 2 weeks
47
What are the Post-op complications of Enucleation surgery
* Bleeding from incision * expected for a few days after surgery * Keep in confined, easily cleaned space * Infection * Cyst formation * uncommon - due to poor surgical technique * Incomplete removal of secretory tissue * Surgery to remove remaining secretory tissue * Contralateral Blindness * Excessive traction placed on optic nerve during surgery * damage to **optic chiasm** * More common in cats (neuro-anatomy) * Blindness is usually irreversible * Avoid w/ gentle surgical practices
48
What is the post-operative care for orbital evisceration surgery
* Topical and oral antibiotic * Systemic NSAIDs +/- analgesics * E-collar
Medicine I
flashcards
Decks in class (43)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions