Ectropion in Cats
Ectropion is a condition which describes the margin of the eyelid rolling outward, resulting in exposure of the sensitive tissue (conjunctiva) lining the inside of the eyelid. Exposure and poor tear distribution may predispose the patient to sight-threatening corneal disease.
It occurs most commonly in dogs but is rarely seen in cats.
Symptoms and Types
Protrusion of the lower eyelid — with lack of contact of the lower lid to the eye globe, and exposure of the palpebral (eyelid) conjunctiva and the third eyelid — can usually be plainly seen. Other signs and symptoms include:
- Facial staining caused by poor tear drainage (i.e., tears spill over onto the face instead of passing from the eye to the nose via the tear ducts)
- Excess eye discharge due to conjunctival exposure
- Recurrent foreign object irritation
- History of bacterial conjunctivitis (inflammation of the conjunctiva)
Ectroprion in cats is usually secondary to breed-associated alterations in facial conformation and eyelid support. The condition is seen more frequently in Persians and Himalayans. Other possible causes include:
- Marked weight loss or muscle mass of the head and eye orbits
- Scarring of the eyelids secondary to injury, or after overcorrection of entropion (a medical condition in which the eyelids fold inward)
A thorough eye exam will be conducted to look for evidence of the eyelid malformation and for corneal ulcerations. A fluorescein stain, a non-invasive dye that shows details of the eye under blue light, will be used to examine the eye for abrasions or foreign objects. In cats with late-age onset, an underlying disorder will be considered as a causative factor. Nerve paralysis in the eye, a condition associated with lack of muscle tone of the eye muscles, will be considered.