Orbit, Eyelid, Lacrimal

Question 1

Physiological exophthalmos (Congenital Orbit Problems): Signalment, treatment

Answer 1

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

Question 2

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

Answer 2

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

Question 3

Strabismus (Congenital Orbit Problems) Types, causes,

Answer 3

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

Question 4

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

Answer 4

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

Question 5

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

Answer 5

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

Question 6

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

Answer 6

– 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

Question 7

Name 3 types of surgery

Answer 7

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.

Question 8

• Enucleation: trans-conjunctival approach

Answer 8

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

Question 9

• Enucleation: trans-palpebral approach

Answer 9

– 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

Question 10

Evisceration surgery

Answer 10

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

Question 11

Exenteration

Answer 11

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

Question 12

Orbitotomy

Answer 12

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

Question 13

Tight medial canthal syndrome

Answer 13

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)

Question 14

Hairy Caruncle

Answer 14

Hairs wicking onto medial cornea.

Question 15

Trichiasis

Answer 15

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

Question 16

3 eyelid problems

Answer 16

1. Trichiasis
2. Distichiasis
3. Ectopic Cillia

Question 17

Distichiasis

Answer 17

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

Question 18

Ectopic Cillia

Answer 18

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

Question 19

Entropion: what is it? Side effects? Treatment?

Answer 19

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

Question 20

Eyelid problems

Answer 20

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

Question 21

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

Answer 21

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

Question 22

Third eyelid problems Prolapsed gland (cherry eye)

Answer 22

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)

Question 23

Everted cartilage (third eyelid)

Answer 23

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

Question 24

Follicular conjunctivitis (third eyelid)

Answer 24

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

Question 25

Neoplasia of the third eyelid (3 types)

Answer 25

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

Question 26

What composes the tear film.

Answer 26

A) Lipid
B) Aqueous
C) Mucous

Question 27

Keratoconjunctivitis Sicca

Answer 27

Not enough tears. Very common.

Question 28

Keratoconjunctivitis Sicca: Etiology

Answer 28

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

Question 29

Keratoconjunctivitis Sicca: Treatment

Answer 29

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