Corneal Ulceration and Perforation

Question 1

What are the causes of corneal ulcers?

Answer 1

(Trauma, corneal abrasions d/t adnexal disease, tear film deficiency, exposure keratitis, and infection)

Question 2

What secondary pathology can happen to an acute superficial ulcer instead of normal healing?

Answer 2

(Chronic superficial ulcer)

Question 3

What are risk factors for delayed corneal healing (most of them are also risk factors for corneal ulcers in general)?

Answer 3

(Abnormal tear production, abnormal blinking, brachycephalic breed, conformational exophthalmos, adnexal abnormalities, and infection of the ulcer)

Question 4

What is distichia?

Answer 4

(Single or multiple abnormal hairs protruding from the meibomian gland openings of the eyelids)

Question 5

You are presented with a 10 year old MN german shepherd dog that has a corneal ulcer. Upon further examination, you also find he has lower eyelid distichia, would you like to pursue further diagnostics?

Answer 5

(Yes bc he’s likely had distichia his whole life so if it was going to cause an ulcer, it would have done it when he was a baby, look for other issues)

Question 6

(T/F) Patients with an ectopic cilia are always symptomatic.

Answer 6

(T)

Question 7

You can readily diagnose keratoconjunctivitis sicca with what test?

Answer 7

(Schrimer tear test)

Question 8

What are the typical causes of exposure keratitis?

Answer 8

(Exophthalmos d/t conformation or orbital dz, buphthalmos d/t glaucoma, or an inability to blink d/t facial paralysis)

Question 9

Neurotropic keratitis is characterized by the loss of corneal sensation resulting in spontaneous non-healing ulceration, issues with which cranial nerve and which branch of that cranial nerve are the cause of this disease?

Answer 9

(Ophthalmic branch of the trigeminal nerve)

Question 10

What disease is characterized by a chronic non-healing superficial corneal ulcer for which no underlying cause can be determined that occurs in middle-aged dogs?

Answer 10

(Spontaneous chronic corneal epithelial defect → SCCED)

Question 11

Sort the following into medical or surgical disease:

Acute superficial ulcer
Corneal perforation
Chronic superficial ulcer
Deep stromal ulcer
Descemetocoele
Mid-stromal ulcer

Answer 11

Acute superficial ulcer (Medical)
Corneal perforation (Surgical)
Chronic superficial ulcer (Surgical)
Deep stromal ulcer (Both)
Descemetocoele (Surgical)
Mid-stromal ulcer (Medical)

Question 12

What are the goals for medical therapy for treatment of an ulcer?

Answer 12

(Prevent/control infection, prevent/control collagenolysis, increase patient comfort, and promote corneal healing)

Question 13

Corneal pain and vascularization in SCCED cases are mild/moderate/severe/variable.

Answer 13

(Variable)

Question 14

(T/F) SCCED lesions very rarely become infected.

Answer 14

(T)

Question 15

What is the purpose of the anterior stromal puncture procedure performed for SCCED cases?

Answer 15

(To penetrate the zone of hyalinized anterior corneal stroma and expose type I collagen → facilitates epithelial adhesion complex formation)

Question 16

The usual treatment plan for an acute superficial corneal ulcer entails topical abx, +/- atropine, +/- systemic analgesics, what medication could be added if it is instead a mid-stromal ulceration?

Answer 16

(Protease inhibitors → systemic tetracycline or topical autogenous serum q 4-6 hours)

Question 17

What are the surgical treatment options for a descemetocele?

Answer 17

(Conjunctival flap or corneoconjunctival transposition)