Page 1262 - Problem-Based Feline Medicine

61. The cat with a cloudy eye

Richard IE Smith

KEY SIGNS
● Cloudiness of the cornea, anterior chamber, lens or vitreous.

MECHANISM
● A cloudy eye is usually caused by a change in the transparency of the clear structures of the
eye.

WHERE?
● Cornea.
● Anterior chamber.
● Lens.
● Vitreous.
WHAT?
● The most common causes of a cloudy eye are diseases that cause edema or scarring of the
cornea, and uveitis, which causes cloudiness in the aqueous humor and/or vitreous as a result
of protein and cells leaking through inflamed uveal blood vessels. Hereditary cataract (opac-
ity of the lens) is rare in cats, but cataracts may develop secondary to uveitis. Nuclear sclero-
sis is a common cause of lens cloudiness in old cats.

QUICK REFERENCE SUMMARY
Diseases causing a cloudy eye
WHERE?

CORNEA
DEGENERATIVE
● Corneal sequestrum (feline keratitis nigrum)** (p 1260)
Presents with an axial (central) area of staining (light brown to black) in the cornea, and is usually
unilateral. Most common in brachycephalic breeds such as Persians and Himalayans. Approximately
80% are associated with herpetic keratitis. In the early stages there is no ulceration, but chronic lesions
may have ulcerated borders surrounded by an inflammatory zone with intense vascularization.

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