Page 1346 - Problem-Based Feline Medicine

1338 PART 15 CAT WITH EYE PROBLEMS

e.g. chronic renal failure, inflammatory bowel disease the cornea is impaired because of an uneven eyelid
or hyperthyroidism. margin.
Third eyelid prominence occurs secondary to loss of
orbital fat and enophthalmos. Diagnosis

Diagnosis is initially based on the appearance of the
Diagnosis lesion, which varies according to the type of tumor.
Diagnosis is based on the generalized body muscle and Definitive diagnosis is by cytological and histological
fat loss, in association with the pronounced enophthal- examination.
mos and third eyelid prominence.
FELINE DYSAUTONOMIA

OTHER NEOPLASTIC DISEASE OF THE
THIRD EYELID* (ADENOMA, Classical signs
ADENOCARCINOMA, MAST CELL TUMOR, ● Unilateral or bilateral third eyelid
LYMPHOMA, HEMANGIOMA) prominence.
● Acute onset of anorexia and depression.
Classical signs ● Other signs of autonomic dysfunction such
as keratoconjunctivitis sicca, mydriasis,
● Mass or erosive lesion involving the third
anisocoria, dry nose or mouth,
eyelid.
bradycardia, constipation, megaesophagus,
● Ocular discharge.
urinary or fecal incontinence.
See main references on page 792 for details (The
Clinical signs
Constipated or Straining Cat).
Tumors of the third eyelid appear as a mass or erosive
lesion involving the third eyelid. Appearance depends
on the type of tumor, which includes lymphoma, Clinical signs
hemangioma, mast cell tumor, adenoma and adenocar-
Third eyelid prominence, in association with any of
cinoma.
a range of other systemic signs suggestive of auto-
● Hemangiomas are rare, are usually dark red to pur-
nomic dysfunction including keratoconjunctivitis sicca,
ple in color, and are fragile with a tendency to hem-
dilated non-responsive pupils, anisocoria, dry nose
orrhage.
and/or mouth, bradycardia, constipation, megaesopha-
● Lymphoma will usually cause more generalized
gus and urinary or fecal incontinence.
swelling of the third eyelid and the peri-orbital tis-
sues, and may be associated with other systemic Typically, the onset of signs is acute over 48 h and
signs of multricentric lymphoma. associated with depression and anorexia.
● Mast cell tumors can form either well- or poorly
circumscribed areas of swelling in the eyelid. They
appear as rapidly growing nodular tumor, often Diagnosis
with poorly defined borders, and variable surface
Diagnosis is based on signs of generalized autonomic
ulceration.
dysfunction.
● Adenomas or carcinomas are seen as a nodular or
diffuse mass causing localized thickening of the Condition is rare or at least uncommon, and most fre-
eyelid. The tumor may have an ulcerated surface. quent in UK.
The neoplastic mass may cause increased ocular Definitive diagnosis is based on the demonstration of
discharge because of third eyelid dysfunction. The characteristic ultrastructural lesions within cell bodies
normal distribution of the precorneal tear film across in autonomic ganglia at post mortem.