A challenging case: Conjunctival lymphoma in a cat
The owner's schedule and financial constraints made the cause of this cat's protruding nictitating membrane a challenge to diagnose and treat.
Jun 01, 2008
A 10-year-old 12-lb (5.5-kg) female spayed domestic shorthaired cat was presented to Colorado State University's Veterinary Medical Center for evaluation of a protruding nictitating membrane of the right eye. The cat's eye had not improved with topical gentamicin ophthalmic drops (1 drop b.i.d.) prescribed two weeks earlier by the referring veterinarian.
FIRST PRESENTATIONPhysical and ophthalmic examinations
The results of a Schirmer tear test and tonometry were normal in both eyes, and there was no corneal staining with fluorescein dye in either eye.
The right eye had scarring and edema of the entire cornea, so the internal ocular structures could not be evaluated. The bulbar and nictitating membrane conjunctiva were moderately hyperemic, and the nictitating membrane protruded and covered about half the cornea. Retropulsion of the right globe was severely limited compared with the left eye. The cat appeared to be in pain.
The remainder of the physical examination findings were normal, and no enlarged lymph nodes were detected on palpation.
We suspected that a right retrobulbar mass was present and recommended ophthalmic ultrasonography to further evaluate the eye. The owner failed to take the cat to the imaging appointment the next day.
Our two differential diagnoses were an extensive retrobulbar mass that was causing venous stasis in the eyelids and conjunctiva leading to swelling or a primary eyelid or conjunctival inflammatory or cellular infiltrate.