Page 1288 - Problem-Based Feline Medicine

1280 PART 15 CAT WITH EYE PROBLEMS

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IRIS
DEGENERATIVE

● Iris atrophy* (p 1287)
Dilated pupil with sluggish pupillary light reflex in an old cat with normal vision. Visible defects
around the pupil margin may occur with atrophy.
● Feline dysautonomia (p 1289)
Variable ocular signs, including reduced lacrimation, dilated non-responsive pupils, anisocoria,
prolapsed third eyelids, photophobia in conjunction with other systemic signs such as constipation,
vomiting and regurgitation, dry mouth or dry nostrils.
ANOMALY
● Iris coloboma (p 1290)
Wedge-like or radial sectorial defect in appearance of the iris.
● Persistent pupillary membranes (PPM) (p 1289)
Small strand-like structures going from one part of the iris collarette to another, to the anterior lens
capsule or to the posterior corneal surface.
● Anisocoria associated with blue irides and deafness in white cats* (p 1287)
Uneven-sized pupils in a white cat, with the larger pupil on the same side as a unilateral blue iris.
INFECTION
● Infectious anterior uveitis – protozoal, fungal or parastic (Toxoplasma,
Cryptococcus neoformans, blastomycosis, coccidioidomycosis, histoplasma
capsulatum, ophthalmomyiasis)** (p 1283)
These infectious organisms may cause chorioretinitis with variable pupil responses, vision loss and
retinal changes, which typically include retinal detachment, subretinal exudates or granulomas.
Signs of anterior uveitis may also be present such as flare, hyperemia of the iris surface, keratic pre-
cipitates and fibrin. Systemic illness is present, typically with pyrexia, inappetence, weight loss and
malaise, and often with dyspnea.
● Feline leukemia virus infection/feline spastic pupil syndrome* (p 1286)
History of variable pupil behavior with pupils alternating between miotic or dilated, in one or both
eyes, over weeks to months. Intervening periods of normality with equal pupils and/or neoplastic
disease affecting the iris, iris thickening and inflammation.

● Feline infectious peritonitis (FIP) virus* (p 1284)
Fibrinous peritonitis, CNS disease or fibrinous uveitis in a young cat with variable vision loss
and/or abnormal pupil reflexes. Anorexia, malaise and/or pyrexia are typically present.
IATROGENIC
● Use of parasympatholytic drugs** (p 1284)
Dilated non-responsive pupil associated with a history of recent use of a drug such as atropine or
tropicamide in the same eye.