diseases and surgery of the orbit

Question 1

ophthalmic examination

Answer 1

retropulsion

orbital palpation

examination of facial symmetry

globe movement

oral exam

nasal airflow

Question 2

retropulsion

Answer 2

should be equal

Question 3

orbital palpation

Answer 3

bony changes

masses in orbit

periocular soft tissue swelling

Question 4

examination for facial symmetry

Answer 4

globe position & alignment

Question 5

globe movement

Answer 5

vestibulo-ocular reflex

direction of gaze

Question 6

oral exam

Answer 6

restricted movement

pain opening mouth

oral mucosa

Question 7

U/s

Answer 7

soft tissue masses within orbit

guide FNA or Bx

Question 8

rads

Answer 8

skull or dental

req general anesthesia

good for bony lesions, radiodense FB

often non-dx

Question 9

MRI/CT

Answer 9

MRI superior for soft tissue imaging

CT superior for detection of bony lesions

evaluates extent of disease

Question 10

FNA/Bx

Answer 10

incisional bx

Tru-Cut

U/s guided

Question 11

exploratory orbitotomy

Answer 11

various approaches

obtain sample for bx

Question 12

diagnostic test for orbital disease

Answer 12

U/s

rads

MRI/CT

FNA/bx

exploratory orbitotomy

Question 13

microphthalmos

Answer 13

congenitally small globe with concurrent ocular abn

differentiate from enophthalmos

often associated with dilute coat color

nonprogressive

no therapy

Question 14

nanophthalmos

Answer 14

congenitally small globe without other abn

Question 15

anophthalmos

Answer 15

congenital absence of globe

rare

Question 16

cyclopia

Answer 16

Veratrum californicum toxicosis in sheep

day 14 in gestation

congenital anophthalmia, cyclopia and synophthalmia

Question 17

strabismus

Answer 17

abnormal eye position

exotropia

eostropia

can be congenital or acquired

Question 18

extropia

Answer 18

divergent

Question 19

esotropia

Answer 19

convergent

Question 20

congenital strabismus

Answer 20

Siamese cats

brachycephalic dogs

hydrocephalus

usually no therapy

Question 21

acquired strabismus

Answer 21

neurological, inflammatory and fibrosing diseases

treat underlying cause

Question 22

orbital cellulitis/abscess

Answer 22

common in SA

underlying cause often not found-FB, ascending tooth root inf, resp dz

Question 23

orbital cellulitis/absces: Presentation

Answer 23

younger animals (avg 4 yo)

acute onset

unilateral exophthalmos, raised nictitans, periorbital swelling, decreased retropulsion

pain opening mouth!

lethargy, pyrexia, leukocytosis

Question 24

orbital cellulitis/abscess: Dx testing

Answer 24

PE

Minimum database

FINA/bx

U/s

MRI

Question 25

orbital cellulitis/abscess: Tx

Answer 25

drain abscess 1) incise oral mucosa posterior to last maxillary molar 2) gently insert hemostats and open (DO NOT CLOSE HEMOSTATS-nerves and aa nearby) 3) swab for C&S 4) Drain and flush Broad spectrum abx, NSAIDs for weeks

Question 26

Orbital neoplasia: presentation

Answer 26

older animals (avg 10 yo) slower progression unilateral sx no pain opening mouth PE and labs-normal

Question 27

Orbital neoplasia: Dx testing

Answer 27

PE Min DB Bx u/s MRI\*\*

Question 28

orbital neoplasia: Px

Answer 28

guarded usually malignant often euthanized shortly after presentation

Question 29

Horner's syndrome: causes

Answer 29

loss of sympathetic innervation to the eye Idiopathic in dogs Gutteral pouch disease in horses trauma otitis media neoplasia rare in cats

Question 30

Horner's syndrome: clinical sxs

Answer 30

enophtalmos raised third eyelid ptosis (mueller's muscle) miosis horse-ipsilateral sweating cow-ipsilateral absence of sweating on the noise

Question 31

Horner's Syndrome: Localize the lesion

Answer 31

denervation hypersensitivity: postganglionic lesions, in absence of NT, muscle upregulates receptors-more sensitive indirect sympathomimetic drugs: preganglionic-pupillary dilation, post ganglionic-minimal to no pupillary dilation direct sympathomimetic drugs: Epi, pre-pupillary dilation 30-40 min, post, pupillary dilation \<20 min

Question 32

Horner's Syndrome: Dx & Tx

Answer 32

pharmacologic testing localizes the lesion further workup based on results: Otic exam, MRI, thoracic rads idiopathic-spontaneously resolves in ~6 weeks other tx-depends on cause post-better px

Question 33

secondary enophthalmos

Answer 33

due to loss of orbital contents or dz of adjacent structures: weight loss, muscle atrophy tx: underlying cause, secondary entropion, conjunctivitis

Question 34

Phthisis bulbi

Answer 34

shrunken globe secondary to chronic/severe infl, glaucoma damage to ciliary body decreases and eventually stops aqueous humor production differentiate from microphthalmos

Question 35

enucleation

Answer 35

removal of globe, eyelid margins, conjunctiva and third eyelid indications: blind, painful eyes, disease limited to the eye (ie galucoma, perforated globe, intraocular tumor)

Question 36

exenteration

Answer 36

enucleation with removal of all orbital contents indications: ocular disease extending beyond sclera (ie intraocular tumor with extrascleral extension)

Question 37

evisceration

Answer 37

removal of ocular contents, leaving only cornea and sclera, followed with placement of prosthesis indications: blind, painful eyes, disease limited to globe, caution with corneal disease

Question 38

orbitotomy

Answer 38

exploratory or therapeutic various techniques varying levels of exposure