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Flashcards in diseases and surgery of the orbit Deck (38)
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1

ophthalmic examination

retropulsion

orbital palpation

examination of facial symmetry

globe movement

oral exam

nasal airflow

2

retropulsion

should be equal

3

orbital palpation

bony changes

masses in orbit

periocular soft tissue swelling

4

examination for facial symmetry

globe position & alignment

 

5

globe movement

vestibulo-ocular reflex

direction of gaze

6

oral exam

restricted movement

pain opening mouth

oral mucosa

7

U/s

soft tissue masses within orbit

guide FNA or Bx

 

8

rads

skull or dental

req general anesthesia

good for bony lesions, radiodense FB

often non-dx

9

MRI/CT

MRI superior for soft tissue imaging

CT superior for detection of bony lesions

evaluates extent of disease

10

FNA/Bx

incisional bx

Tru-Cut

U/s guided

11

exploratory orbitotomy

various approaches

obtain sample for bx

12

diagnostic test for orbital disease

U/s

rads

MRI/CT

FNA/bx

exploratory orbitotomy

13

microphthalmos

congenitally small globe with concurrent ocular abn

differentiate from enophthalmos

often associated with dilute coat color

nonprogressive

no therapy

14

nanophthalmos

congenitally small globe without other abn

15

anophthalmos

congenital absence of globe

rare

16

cyclopia

Veratrum californicum toxicosis in sheep

day 14 in gestation

congenital anophthalmia, cyclopia and synophthalmia

17

strabismus

abnormal eye position

exotropia

eostropia

can be congenital or acquired

18

extropia

divergent

19

esotropia

convergent

20

congenital strabismus

Siamese cats

brachycephalic dogs

hydrocephalus

usually no therapy

21

acquired strabismus

neurological, inflammatory and fibrosing diseases

treat underlying cause

22

orbital cellulitis/abscess

common in SA

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

23

orbital cellulitis/absces: Presentation

younger animals (avg 4 yo)

acute onset

unilateral exophthalmos, raised nictitans, periorbital swelling, decreased retropulsion

pain opening mouth!

lethargy, pyrexia, leukocytosis

24

orbital cellulitis/abscess: Dx testing

PE

Minimum database

FINA/bx

U/s

MRI

25

orbital cellulitis/abscess: Tx

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

 

26

Orbital neoplasia: presentation

older animals (avg 10 yo)

slower progression

unilateral sx

no pain opening mouth

PE and labs-normal

27

Orbital neoplasia: Dx testing

PE

Min DB

Bx

u/s

MRI**

28

orbital neoplasia: Px

guarded

usually malignant

often euthanized shortly after presentation

29

Horner's syndrome: causes

loss of sympathetic innervation to the eye

Idiopathic in dogs

Gutteral pouch disease in horses

trauma

otitis media

neoplasia

rare in cats

30

Horner's syndrome: clinical sxs

enophtalmos

raised third eyelid

ptosis (mueller's muscle)

miosis

horse-ipsilateral sweating

cow-ipsilateral absence of sweating on the noise

31

Horner's Syndrome: Localize the lesion

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

32

Horner's Syndrome: Dx & Tx

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

33

secondary enophthalmos

due to loss of orbital contents or dz of adjacent structures: weight loss, muscle atrophy

tx: underlying cause, secondary entropion, conjunctivitis

34

Phthisis bulbi

shrunken globe

secondary to chronic/severe infl, glaucoma

damage to ciliary body decreases and eventually stops aqueous humor production

differentiate from microphthalmos

35

enucleation

removal of globe, eyelid margins, conjunctiva and third eyelid

indications: blind, painful eyes, disease limited to the eye (ie galucoma, perforated globe, intraocular tumor)

36

exenteration

enucleation with removal of all orbital contents

indications: ocular disease extending beyond sclera (ie intraocular tumor with extrascleral extension)

37

evisceration

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

38

orbitotomy

exploratory or therapeutic

various techniques

varying levels of exposure