Entropion is an inward rolling of the eyelids. Lower lid entropion is more common than upper lid entropion.
Why does my cat have this?
- Congenital (since birth)
- Result of injury or inflammation
Entropion permits the lid hairs to rub against the cornea.
- Chronic conjunctivitis
- Purulent ocular discharge
- Corneal ulceration
- Weeping eyes
- Painful eyelid spasm
Anatomic entropion is uncommon in cats, although pure breeds are more likely to be affected. Brachycephalic cats (Persians and Himalayans) typically have lower lid entropion close to their nose (medial canthal entropion).
Aquired entropion occurs in the cat and often only affects one eye. Spastic entropion may develop secondary to corneal disease, conjunctivitis, ocular pain, etc. in any age and breed of cat. Spastic entropion can become permanent if allowed to persist. It is believed that ocular surface diseases associated with feline herpesvirus-1 (FHV-1) may be the most common cause of acquired entropion in the cat. These cases eyelid conformation is normal at birth but entropion develops later, usually after chronic ocular irritation has occurred.
Older cats may develop secondary entropion with profound weight loss.
Many cats with entropion have mucoid ocular discharge, painful eyelid spasms and are often treated for conjunctivitis without any clinical improvement. The irritation from the hairs rubbing on the cornea and the conjunctiva can cause mucoid conjunctivitis, corneal vascularization and/or ulceration. With prolonged irritation to the cornea, cats with entropion may develop corneal sequestration.
In most cases the diagnosis is obvious on the clinical examination. The eyelid hairs can be visualized rubbing on the cornea. Spastic entropion usually reverses after application of topical local anaesthetics. Anatomic entropion does not reverse with local anaesthesia. Local anaesthetic is used to further examine the eye. Fluorescein staining of the cornea is done to assess for ulcers and closely examine for secondary changes (e.g. vascularization, pigmentation, scarring, sequestrum formation) from the entropion.
In almost all cases surgery is required to correct feline entropion. This involves excising an elliptical piece of skin in the area of inrolling and suturing the defect closed to roll the eyelid out (similar to a face lift for the eyelid!!). It is a matter of clinical judgement and experience as to how much tissue should be removed.