Ophtho 1 & 2

Question 1

90% of thickness of eye

Answer 1

Is made up by the stroma
Lamellar collagen arrangement
400-800um thick in dogs/cats
Avascular, clarity is critical to function

Question 2

Optical clarity maintained by

Answer 2

Non-keratinized epithelium
Regular stromal collagen arrangements
Small diameter collagen fibrils
Lack of BV
Relative dehydration
Pre-corneal tear film

Question 3

4 pathologic corneal diseases

Answer 3

Edema
Vacularization
Pigmentation - species dependent
Scarring/fibrosis

Question 4

Congenital corneal disorders

Answer 4

Dermoid
Persistent pupillary membranes

Question 5

PPMs

Answer 5

Embryologic structure that nurses the eye
Strands of tissue, that cause localized edema

Question 6

Corneal ulceration

Answer 6

Full thickness of epithelium

Question 7

Clinical signs for corneal ulceration

Answer 7

Blinking/squinting
Localized corneal edema
Conjunctival hyperemia/chemosis
Variable ocular discharge

Question 8

causes for corneal edema

Answer 8

Trauma** (exogenous vs endogenous)
KCS
Prolonged corneal exposures (FN paralysis, exopthalmos)
Primary infections - FHV1, EHV2, CHV, m.bovis

Question 9

Endogenous sources of corneal trauma

Answer 9

Entropion - enrolling on the lid
Ectopic cilia - conformational, eyelash on lense
Distichia - hairs outside the eyelid margin
Nasal fold trichiasis - folds near nose rub on eyes

Question 10

Corneal healing - epithelial

Answer 10

Epithelial sliding and mitosis - quicker healing

Question 11

Corneal healing - stromal defect

Answer 11

More damage or secondary
Epithelial healing+ keratocyte proliforation and collagen deposit
Will result in a cloudy scar

Question 12

Normal corneal healing

Answer 12

Quickly, 7-10 days often quicker
Anything past that = something else is wrong

Question 13

Specific causes for delayed corneal healing

Answer 13

Corneal infection
Unresolved source of corneal abrasion
KCS
Exposure keratitis
Neurotrophic keratitis
SCCED - boxer ulcer

Question 14

Risk factors for ulcer progression

Answer 14

Tear production normal ?
Can & does the animal blink normally?
Brachycephalic breed/conformational exophthalmos
Adnexal abnormalities
Does ulcer appear infected

Question 15

Corneal ulceration complications

Answer 15

Secondary infections**
Stromal collagenolysis
Uveitis
Corneal perforation

Question 16

Descriptive classification of corneal ulcers

Answer 16

Superifical
Stromal
- mid Stromal
- deep stromal
Desemetocele

Question 17

Diagnostic for eye

Answer 17

Search for underlying cause
Schirmer tear test
Corneal culture
Corneal cytology
Florescein stain

Question 18

Goals of therapy

Answer 18

Prevent/control infection
Prevent/control collagenolysis
Increase patient comfort
Promote health

Question 19

Types of medical therapy for corneal ulceration

Answer 19

Antimicrobials - topical
Anti proteolytic agents
- topical autogenous serum
- topical n-acetylcysteine
- systemic tetracyclines

Question 20

Other medical therapy types

Answer 20

Cycloplegic agents - topical atropine
Other - analgesia, e-collar

Question 21

Duration for medical therapy

Answer 21

As long as it takes for the epithelium to cover and protect the lesion - tested with fluorescence stain, negative uptake

Question 22

Topical steroids

Answer 22

Contraindicated use in presence of corneal ulcers
Can inhibit healing, can prolong ulcers

Question 23

Surgical therapy

Answer 23

SCCED - chronic corneal ulcers
Progressive corneal ulceration
Deep stromal ulcers/descemetocoele
Keratomalacia - melting ulcers

Question 24

Types of surgical therapy

Answer 24

Keratectomy - removal of necrotic/infected corneal
Corneal/biomaterial graft - structural support
Conjunctival flap/graft - speeds healing of cornea
3rd eye lip flap XX do not use for healing

Question 25

Conjunctival flaps

Answer 25

Mechanical support Immediate blood supply Source of fibroblasts Source of epithelial cells

Question 26

SCCED

Answer 26

Spontaneous chronic corneal epithelial defect *boxer ulcer Superficial, non healing ulceration Non-infected Loose epithelial lip surrounding ulcer Variable vascularization Variable pain/discomfort

Question 27

Treatment for SCCED

Answer 27

Debride the cornea Keratotomy/tectomy Manage superficial ulcer till healed

Question 28

FHV1 keratitis

Answer 28

Corneal ulceration Dendritic ulcers/erosions Classic early lesion, rose bengal staining- highlights epithelial ulcers better than florescence Superficial ulceration/stromal ulceration

Question 29

other FHV corneal conditions

Answer 29

Stromal keratitis, corneal sequestrum, eosinophilic keratitis

Question 30

FHV keratitis treatment

Answer 30

Topical antibiotics if ulceration present Antiviral (topical/oral)** Anti inflammatories (topical NSAIDS)

Question 31

Canine herpes virus

Answer 31

Not super common Ubiquitous infections Dendritic ulcers or non ulcerative inflammatory DS

Question 32

Infectious bovine keratoconjuctivitis

Answer 32

Pink eye Spread by moraxella bovis Highly contagious - direct contact & mechanical vectors

Question 33

Etiopathalogic factors for IBK

Answer 33

Bacteria related - pili, cytotoxin Co- infections Host related - genetics, age, immunity, stress/nutrition Environmental - UV exposure, dry/dusty enviro

Question 34

Ocular lesion of IBK

Answer 34

Corneal ulcer - can progress to rupture Conjunctivitis, blepharospasm, photophobia, epiphora, mucopurulent discharge

Question 35

Preventing IBK

Answer 35

No good vaccine Environmental control is best Parenteral antibiotics Subconjuncival antibiotics* Topical antibiotics

Question 36

Corneal foreign body

Answer 36

Removal is mandatory - caution w potential perforation - surgical intervention in select cases Topical antibiotics until healed

Question 37

Corneal laceration/perforation

Answer 37

Partial thickness - Medical management if superficial (<50% corneal thickness) Full thickness - surgical intervention probably

Question 38

Non ulcerative corneal disease

Answer 38

Corneal abscess Pigmentary keratitis Immune mediated keratitis Chronic superficial keratitis (pannus) Lipid keratopathy Corneal mineralization /calcification keratopathy

Question 39

Corneal abscess

Answer 39

Uncommon Intrastromal cellular accumulation Infected vs sterile Must vascularize to heal - medical vs surgical

Question 40

Pigmentary keratitis

Answer 40

Not a specific disease - typically a result of underlying condition causing chronic irritation Most common & severe in Brachycephalic dogs Treat underlying conditions, topical cyclosporine or tacrolimus to clear pigment