Lecture 23 Pt 2 5/1/25 (Large Animal)

Question 1

What is mycotic keratitis?

Answer 1

inflammation of the cornea due to infection with fungal organisms; in horses

Question 2

What are the clinical signs and history of mycotic keratitis?

Answer 2

-possible recent topical antibiotics/steroids
-white stromal infiltration
-keratomalacia
-secondary uveitis
-corneal furrow
-very painful

Question 3

What are the variants of mycotic keratitis?

Answer 3

-ulcerative stromal keratitis (most common)
-stromal abscessation
-superficial raised plaque of fungus mat
-punctate keratitis
-non-ulcerative epithelial roughening (least common)

Question 4

What is the etiology of mycotic keratitis?

Answer 4

-generally filamentous fungi
-Fusarium, Asperigillus, and Candida
-can occur with abnormal tear film, traumatic injury, or epithelial insult

Question 5

How is mycotic keratitis diagnosed?

Answer 5

-corneal scraping for cytology
-culture to identify genera and species
-sensitivity (special lab)

Question 6

What is the treatment for mycotic keratitis?

Answer 6

-topical antifungals
-stromal injections with voriconazole
-topical antibiotics
-topical atropine (MUST DO)
-oral NSAIDs (MUST DO)
-AVOID steroids

Question 7

When is surgery recommended for mycotic keratitis?

Answer 7

-progression despite medical treatment
-deep ulceration
-deep abscessation

Question 8

What is the prognosis for mycotic keratitis?

Answer 8

-depends on response to therapy within first few days
-may progress to fungal endophthalmitis; fungi can rupture Descemet’s membrane
-requires prolonged clinical course of treatment
-can cause significant corneal scarring

Question 9

What is a corneal stromal abscess?

Answer 9

accumulation of leukocytes and infectious organisms beneath intact corneal epithelium; seen in horses

Question 10

What are the clinical signs and history of corneal stromal abscess?

Answer 10

-may have a history of trauma
-focal white-yellow infiltrate with accompanying keratitis
-fluorescein negative
-secondary reflex uveitis; vision threatening!
-painful

Question 11

What is the etiology of corneal stromal abscess?

Answer 11

-usually initiated by trauma
-infection is sealed by epithelium
-most often fungal; can be bacterial

Question 12

How is corneal stromal abscess diagnosed?

Answer 12

-clinical appearance
-cytology
-histopath.
-culture
-sensitivity
often need surgery to get diagnostic specimens for C&S

Question 13

What is the treatment for corneal stromal abscess?

Answer 13

-topical antibiotics and/or antifungals that PENETRATE intact epithelium
-control of secondary uveitis with oral NSAIDs and atropine
-possible topical NSAIDs for secondary uveitis
-keratectomy or pedicle conjunctival graft if surgical
-treatment until vessels come AND go and there is no uveitis with removal of anti-inflammatories

Question 14

What is the goal of medical and surgical treatment for corneal stromal abscess?

Answer 14

*medical:
-encourage development of blood vessels to clean up infection
*surgical:
-cut out all of the infection

Question 15

What is the prognosis for corneal stromal abscess?

Answer 15

-prognosis is better for small lesions and lesions closer to limbus
-overall good success; 87-98% of patients are visual and comfortable post-op
-surgery may be necessary to control disease
-corneal scarring depends on size of abscess

Question 16

What are the characteristics of subpalpebral lavage?

Answer 16

-allows for treatment without having to repeatedly touch the face
-typically used for infectious dz but can be used for any ocular conditions
-used in horses, cattle, and small ruminants