Page 1273 - Problem-Based Feline Medicine

61 – THE CAT WITH A CLOUDY EYE 1265

Clinical signs ● Signs of multifocal neurologic disease.
● Liver disease.
Rare disease of young Manx cats. Cats present with
an axial (central) stromal edema which progresses to Ocular signs are more common, and may include one
diffuse corneal edema and a thickened corneal stroma or all of the following signs:
filled with bullae (fluid-filled vesicles). ● Anterior uveitis is the most common sign and
is seen as a cloudy anterior chamber. This is
Affected cats become blind.
caused by leakage of protein and white blood
cells from inflamed iris and ciliary body blood
Diagnosis vessels into the aqueous humor. It is also known as
hypopyon.
A tentative diagnosis is based on the presentation of
● In severe cases of uveitis, the cornea may be
a young Manx cat with corneal edema.
cloudy due to edema caused by aqueous leakage
A definitive diagnosis is based on histopathology. through a compromised endothelium.
● Histology demonstrates progressive disintegra- ● Keratic precipitates may be seen on the surface of
tion of stromal collagen fibers, which are replaced the endothelium. These are the so-called “mutton
with fluid-filled vesicles. Eventually the epithelium fat” deposits that consist of white cells and protein
separates from its basement membrane and ulcera- attached to the endothelium. They are more com-
tion occurs. mon in the inferior cornea.
● Cloudy vitreous caused by chorioretinitis; white
cells and protein leak into the vitreous through
DISEASES CAUSING A CLOUDY
ANTERIOR CHAMBER inflamed retinal and choroidal blood vessels.
● Lymphocytic plasmocytic uveitis is seen as pale
nodules on the iris surface.
TOXOPLASMA GONDII ● Secondary cataract formation is common in chronic
(TOXOPLASMOSIS)** cases, and will be seen as a cloudy eye within the
pupil space.
Classical signs ● Glaucoma is a sequel to chronic uveitis.
● Signs may be unilateral or bilateral.
● Cloudy anterior chamber from anterior
uveitis is the most common sign.
● +/- Gray to tan-colored nodules on the iris Diagnosis
surface (lymphocytic-plasmacytic uveitis).
● Cloudy vitreous (chorioretinitis and optic A tentative diagnosis may be based on the clinical
neuritis). signs.
● Rarely, systemic signs may be seen
A definitive diagnosis requires supportive laboratory
concurrently with ocular signs.
● These include fever, weight loss, +/- data which may include:
● Serology.
muscular pain, +/- signs of respiratory or
– Demonstration of a rise in IgM titers indicates
neurological disease.
a recent active infection.
– Comparison of levels of aqueous humor
See the main reference on pages 1296, 1169 (The Cat
T. gondii antibody levels with serum levels
With Abnormal Iris Appearance and The Blind Cat or
(Goldman–Witmer coefficient or C-value) has
Cat With Retinal Disease).
been advocated, with higher aqueous levels
suggesting the anterior uveitis was caused by
Clinical signs
T. gondii. The use of C-values is still contro-
Systemic signs are rare but may include: versial.
● Fever, weight loss and muscle pain. ● Polymerase chain reaction (PCR) testing for para-
● Respiratory signs associated with pneumonia. site DNA in tissue or fluid samples.