Page 1250 - Problem-Based Feline Medicine

1242 PART 15 CAT WITH EYE PROBLEMS

Herpetic keratitis. ophthalmology text which describes the surgery in
● Very chronic cases may have a dense white superfi- detail (see references).
cial scar with degrees of corneal vascularization.
This scarred area may slowly develop a faint stain Prognosis
and progress to a dense black plaque, typical of
corneal sequestrum. The initial changes in corneal The prognosis in cases that slough after medical man-
sequestration are subtle and may be missed. agement is reasonable. Some of these lesions may
● PCR tests may help to associate this disease with recur, and scarring will be intense causing vision
corneal sequestrum. impairment. However, cats with axial scarring seem to
be able to lead a reasonably normal lifestyle.
Eosinophilic keratitis.
● The lesion is proliferative with an intense corneal Healing after pedicle grafts or cornea–scleral grafts is
edema and vascularization. There is no brown good, but scarring is present. Scarring is less intense
staining. after a sliding corneo–scleral graft as the opaque
● Cytology shows the presence of eosinophils. grafted scleral tissue is confined to the outer cornea.

Ulcerative keratitis. Keratoplasty has not been widely embraced by veteri-
● There is a positive stain to fluorescein in the initial nary ophthalmologists because rejection, vasculariza-
stages. tion and scarring of grafts occurs in other animal
● Chronic healing ulcers may be vascularized and species. However, the cat cornea reacts more like
have edema (white). There is no brown pigment, human cornea to grafting than other animals, and there-
but occasionally ulcers may progress to form a fore, is supposed to be amenable to full-thickness ker-
corneal sequestrum. atoplasty.

Transmission
Treatment
Apart from FHV-1 infection, there is no known trans-
Try to identify the cause and eliminate this. Medial
mission of this disease from one cat to another. Cases
entropion and FHV-1 keratitis are the two most com-
with herpetic keratitis have the same etiopathogenesis
mon causes that need to be addressed. Surgically cor-
as is described under this heading.
rect medial entropion and treat FHV-1 keratitis with an
anti-viral agent (see Herpes keratitis, page 1239).
Prevention
Conservative management is encouraged by some oph-
thalmologists, as some lesions may spontaneously There is no known prevention, apart from palliative
slough and the cornea heals with a scar. Broad-spectrum treatment of corneal ulcers and herpetic keratitis. Cases
antibiotic ointments such as neomycin and polymixin, associated with medial entropion should have surgical
chloramphenicol or fucidic acid are used to lubricate correction of the eyelid problem.
the eye and guard against bacterial infection. Antiviral
agents are often used to suppress the effects of herpetic ULCERATIVE KERATITIS CAUSED
keratitis. Artificial tear solutions may provide some BY CORNEAL PERFORATION (CAT
relief from irritation and corneal drying. FIGHT WOUNDS)**

Surgical management is the preferred option by the
Classical signs
majority of ophthalmologists. The diseased stroma is
resected by lamellar keratectomy, and the stromal ● Acute very painful eye guarded with
defect closed with either a pedicle conjunctival graft or blepharospasm. Serous discharge, often
a sliding corneo-scleral graft. Partial- or full-thickness containing blood.
keratoplasty (corneal graft) has been used in an attempt ● Very cloudy cornea usually with a linear
to minimize corneal scarring, but results have not been wound or triangular tear that is plugged
very encouraging as the cornea vascularizes and scars. with fibrin.
For surgical techniques readers should refer to an