Enophthalmos is a sinking of the eyeball back into the socket (orbit). This is an uncommon finding in the cat, and it can involve one of both eyes.
General Causes of Enophthalmos in Cats
Ocular (eye) pain
Shrinkage of the eye following trauma (phthisis bulbi)
Horner’s syndrome, from a loss of neurologic innervation to the eye
Severe dehydration with shrinkage of the soft tissues behind both eyes
Loss of orbital fat or muscle
Occasional displacement of the eye from cancer of the orbit or nose
What to Watch For
The eye is less visible than before
Usually the eye is a normal size and is just sitting further back in the orbit
Third eyelid protrusion
Secondary entropion (turning inward of the eyelid margin)
Other signs depending upon the cause; may include changes in the appearance of the face, discharge from the nose, and evidence of weight loss and dehydration.
Diagnosis of Enophthalmos in Cats
A thorough ocular evaluation is of paramount importance. Both eyes are closely examined. Schirmer tear tests, fluorescein staining of the cornea, tonometry, testing of reflexes to the nerves of the head and examination of the retina are all indicated. It should be determined whether one or both eyes are involved and if there are any other eye or facial abnormalities present.
If a generalized illness is suspected, additional tests include:
Complete blood cell count (CBC)
Thoracic (chest) +/- cervical (neck) X-rays in cases of Horner’s syndrome, and possibly abdominal X-rays in cases of severe weight loss.
CAT scan or MRI of the head
Treatment of Enophthalmos in Cats
Depending on the underlying cause, specific therapy may be indicated:
Intravenous fluid therapy and support are given to cats that are dehydrated due to an inability to eat and drink, secondary to other disease such as kidney disease or cancer.
If ocular pain is the cause of the enophthalmos, then the underlying eye disease (e.g. corneal ulceration) is treated appropriately.
Loss of fat around the eye socket (orbital fat) is difficult to rectify, although slight improvement in the position of the eye may occur with substantial weight gain.
There is no treatment available for shrinkage of the eye (phthisis bulbi).
There is no specific treatment for Horner’s syndrome. Some cases of Horner’s syndrome are permanent, yet others resolve on their own over several weeks.
Home Care and Prevention
Administer any prescribed medications as directed by your veterinarian and return for follow up as directed.
Due to the many causes of enophthalmos, there is no specific preventative care.