Page 1315 - Problem-Based Feline Medicine

64. The cat with abnormal globe position

or size

Michael E. Bernays

KEY SIGNS
● Increased globe prominence.
● Increased globe size.
● Reduced globe prominence.
● Reduced globe size.

MECHANISM?
● A globe which is more prominent may be either enlarged (buphthalmic) or a normal-sized
globe which is abnormally positioned, usually displaced cranially (exophthalmic).
● A globe which is less prominent may be shrunken (pthisis), or it may be a normal-sized globe
which is positioned more caudally or deeper in the orbit (enophthalmic).
WHERE?
● Globe.
● Orbit.
WHAT?
● The most common causes of abnormal globe positioning or size in the cat are:
● Increased prominence: orbital cellulitis or orbital neoplasia.
● Increased size: chronic glaucoma causing enlargement.
● Reduced prominence: shrinkage of orbital tissue related to loss of orbital fat.
● Reduced size: pthisis (shrinkage) due to intractable inflammation causing low
intra-ocular pressure or globe leakage due to a persistent corneal or scleral defect.

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