Cherry eye / prolpased gland of the nictitating membrane

What is cherry eye?
This is the term commonly used to describe a prolapsed lacrimal gland of the third eyelid. The prolapsed gland is a pink mass and appears similar in shape and colour to a cherry. 

What is the third eyelid?
Many animal species have a third eyelid (nictitating membrane) that is normally hidden behind the lower eyelid. The third eyelid sweeps across the surface of the eye (cornea) in a mechanism similar to a windscreen wiper   
 

What is the third eyelid gland and why is it important?
A gland is present at the base of the third eyelid, and this is responsible for producing approximately 60% of the tears. The gland is normally held in place by a small ligament. If the small ligament breaks the gland moves out of position (prolapse) and becomes visible.  If the gland is damaged or removed, a reduction in tear film production would be expected which can lead to significant corneal disease (see dry-eye)

Are particular animals at risk of developing cherry-eye?
Yes, most cases are seen in dogs before one year of age. Certain breeds such as Bulldogs, Great Danes, Mastiffs, Lhasa Apso and Shih Tzus are more commonly seen with the condition. The condition is less commonly seen in cats and rabbits.

What is the treatment for cherry eye?
The gland needs to be repositioned surgically under general anaesthesia. A small ‘pocket’ is created at the base of the third eyelid and the gland is held in place with self-dissolving sutures (stitches). Patients will usually receive a course of topical and oral medication post-operatively.