Orbit, Eyelid, Lacrimal Flashcards Preview

Dog & Cat Medicine and Surgery > Orbit, Eyelid, Lacrimal > Flashcards

Flashcards in Orbit, Eyelid, Lacrimal Deck (29):
1

Physiological exophthalmos (Congenital Orbit Problems): Signalment, treatment

Brachycephalic breeds
– Shallow orbit
– Inadequate blink response
• Sleep with eyes open!
– Canthoplasty
• Shorten palpebral fissure

2

Microphthalmia (Congenital Orbit Problems): what is it? other issues? Treatment?

– Small ocular globe
• Intraocular anomalies
– Congenital, genetic
– Severe: blindness
• enucleation

3

Strabismus (Congenital Orbit Problems) Types, causes,

– Bilateral
– Congenital or genetic
– Severe: blindness
– Muscle or innervation
– Challenging to repair

4

Eosinophilic myositis (Acquired Orbit Problems) what is it? Signalment? Acute/Chronic problems? Treatment?

– Bilateral exophthalmos
– Large breeds
– Initially
• Painful mastication
– Chronic
• Muscle atrophy
– Muscle biopsy
– Corticosteroids

5

Neoplasia: (Acquired Orbit Problems): what do you see? diagnosis? Treatment?

– Progressive exophthalmia
• No pain on opening mouth – Malignant
– Ocular ultrasound • CT/MRI
– Exenteration/Orbitectomy/Orbitotomy • Radiation?

6

Causes of enopthalmia (Acquired Orbit Problems) - name 3.

– Loss of orbital tissue mass
• Dehydration, weight loss, cachexia, muscle loss • Facial fractures
– Horner’s syndrome
• Enophthalmia leads to ptosis of upper eyelid and
protrusion of third eyelid
– Ocular pain
• Corneal/ conjunctival ulceration, uveitis, glaucoma • Activation of retrobulbar muscle cone

7

Name 3 types of surgery

1. Enucleation - removing the eyeball itself
2. Exenteration - remove the eyeball and everything else (muscle, orbital fat)
3. Evisceration - remove just the intra-ocular contents.

8

• Enucleation: trans-conjunctival approach

– Lateral canthotomy
– 360 degree conjunctival incision
– Incision of muscles and optic nerve
– Close in 3-4 layers

9

• Enucleation: trans-palpebral approach

– Suture eyelids together
– 360 degree incision around eyelids
– Sharp and blunt dissection towards globe – Incision of muscles and optic nerve
– Close in 3-4 layers

10

Evisceration surgery

– Lateral canthotomy
– Incision of conjunctiva
– 2 stay sutures in sclera
– Remove intraocular content – Place silicone prosthesis
– Close all incisions

11

Exenteration

– Removal of orbital content
• Ocular globe, third eyelid, extraocular muscles, orbital
fat pad

12

Orbitotomy

– Exploration of orbit
• Imaging: CT scan or MRI
• Temporary removal of zygomatic arch

13

Tight medial canthal syndrome

Especially the bug-eyed dogs (e.g. boston terriers) the eyelids are really tight against the eyeball (sometimes in poodles) that if the tears don't go right down the tear duct, it'll go down the face. No room for tears to collect. (shitzu's)

14

Hairy Caruncle

Hairs wicking onto medial cornea.

15

Trichiasis

: normally placed hair that curls and comes into contact with the eyeball.

16

3 eyelid problems

1. Trichiasis
2. Distichiasis
3.Ectopic Cillia

17

Distichiasis

A distichia is an eyelash that arises from an abnormal spot on the eyelid.
In the mybomium gland comes into contact with the cornea. Mibomeum glands should not have hair follicles

18

Ectopic Cillia

Comes through the palpebral conjunctiva. It's like a second row of eyelashes.

19

Entropion: what is it? Side effects? Treatment?

Rolling in of the lower eyelid.
(e.g. Sharpei)
– Rolling outward
– Breed standard
• Scarring
– Conjunctivitis
– Various surgeries

20

Eyelid problems

• Blepharitis – Chalazion
– Hordoleum – Cellulitis
• Allergic
• Parasites
• Auto-immune

21

Neoplasia in eyelids. Most common kind? Tests? Treatment?

• Neoplasia
– Meibomian gland adenoma
• FNA
• Excision
– Wedge if < 1/3
– 2 layer closure • Conjunctiva
• Skin

22

Third eyelid problems Prolapsed gland (cherry eye)

Lacrimal gland of the third eyelid is visible instead of deep seated. It is congenital/genetic and an ovoid mass. There are a lot of ways to remove it. (e.g. pocket technique)

23

Everted cartilage (third eyelid)

It can be a familial/genetic trade causing the scrolling of cartilage. You treat it by removing the bent stem.

24

Follicular conjunctivitis (third eyelid)

Often due to renovations/dust in the house that causes follicular conjunctivitis in often young dogs.
• Follicular conjunctivitis – Lymphoid hyperplasia – Conjunctivitis
• Debride follicles
• Antibiotic-steroid therapy – Topical TID

25

Neoplasia of the third eyelid (3 types)

- Gland: adenocarcinoma
– Conjunctiva:
• Hemangioma, melanoma...
– Lymphoid follicles
• Lymphoma – Biopsy
– Excision

26

What composes the tear film.

A) Lipid
B) Aqueous
C) Mucous

27

Keratoconjunctivitis Sicca

Not enough tears. Very common.

28

Keratoconjunctivitis Sicca: Etiology

• Etiology
– Immune mediated
– Heritable
– Neurogenic
– Infectious: FVH, Distemper – Drug reaction

29

Keratoconjunctivitis Sicca: Treatment

Medical Treatment
– Tear stimulant • Cyclosporine
• Tacrolimus
– Tear supplement
• Surgical Treatment – PDT