Page 1345 - Problem-Based Feline Medicine

66 – THE CAT WITH AN ABNORMAL THIRD EYELID 1337

except that vision might be improved where the third Clinical signs
eyelid prominence and enophthalmos is extreme, caus-
The third eyelid is prominent because of retraction of
ing most of the globe to be covered by nictitans.
the globe, associated with ocular pain.
Prognosis It is associated with ipsilateral signs of ocular pain,
for example, enophthalmos, blepharospasm, corneal
Depending on the cause many cases may resolve disease, pupil miosis or anterior uveitis.
over time as denervated smooth muscle re-innervates,
provided that oculosympathetic fibers are not totally
Diagnosis
destroyed.
Diagnosis is based on signs of ocular pain together with
TRAUMA TO THE THIRD EYELID MARGIN* prominence of a normal-appearing third eyelid.

Classical signs Differential diagnosis

● Notch-like or linear tears arising from the Horner’s syndrome and Haws are usually non-
third eyelid margin. painful.
● Usually unilateral, with the contralateral
Horner’s syndrome, tetanus and feline dysautonomia
eye unaffected.
each have their own specific associated clinical signs,
which are more suggestive of that particular condition.
Clinical signs
Treatment
Trauma to the third eyelid may result in notch-like or
linear tears starting at the margin of the third eyelid. Treat the cause of the ocular pain as indicated.
These occur most commonly from cat fights.
Third eyelid trauma may be associated with other ocu-
THIRD EYELID PROMINENCE RELATED
lar signs, when seen in the acute stages, e.g. conjuncti-
TO SEVERE WEIGHT LOSS*
val chemosis and ocular discharge (see The Cat
With Ocular Discharge or Changed Conjunctival
Classical signs
Appearance, page 1211).
● Signs of generalized muscle wasting
Diagnosis associated with chronic disease.
● Thin face with signs of muscle wastage
Diagnosis is based on the clinical signs, and the history around the lateral aspects of the orbit.
of unilateral third eyelid notch or tear occurring after ● Bilaterally symmetrical third eyelid
a possible fight with another cat. prominence without miosis or upper lid
ptosis.
THIRD EYELID PROMINENCE RELATED
TO OCULAR PAIN* Clinical signs

Classical signs Typically these cats have a bilaterally symmetrical third
eyelid prominence due to marked enophthalmos, and
● Third eyelid prominence.
there are no other signs normally associated with other
● Associated with other ipsilateral signs of
causes of third eyelid prominence such as miosis or
ocular pain, e.g. enophthalmos,
upper lid ptosis.
blepharospasm, corneal disease, pupil
miosis. Generalized whole-body muscle wasting is present in
association with signs of other organ system disease,