Why does it occur?
Prolapsed gland of the third eyelid (nictitans) is often referred to as “cherry eye.” The gland is actually one of two tear glands positioned around each eye in dogs and cats. The prolapse occurs due to a weakness of the connective tissues that hold the gland in place. The gland is normally attached out of sight to the base of the third eyelid, at the inside corner of the eye. When the tissue attachment releases, the gland rises up and becomes visible at the leading edge of the third eyelid. At that time, a smooth red mass will be seen. This condition is seen with higher prevalence in certain breeds of dogs including Cocker Spaniels, Beagles, Chihuahuas, Mastiffs and brachycephalic breeds (e.g. Bulldogs, Boston Terriers, Pugs). The condition most commonly affects dogs that are less than 2-3 years of age, and it can affect one or both eyes.
Should I be concerned if it occurs?
The condition is not painful, however the gland can will become inflamed due to exposure and dryness. With increased inflammation the gland becomes swollen and can be easily traumatized and even bleed. It is important to preserving the health and function of the third eyelid tear gland as it produces approximately 30% of the aqueous tear production for the eye. Without treatment, eyes with prolapsed tear glands develop conjunctivitis, abnormal eye discharge and are at increased risk for developing dry eye. When combined with dry eye, eyes with prolapsed glands more often develop corneal ulcers, ocular infections, corneal vascularization, corneal scarring, and corneal mineralization.
What is the treatment?
The recommended treatment for prolapsed glands is surgical repositioning. Based upon ophthalmic examination, age and breed of your pet, the ophthalmologist may advise preventatively treating the opposite eye as many patients ultimately develop gland prolapse in both eyes. Surgical success rate is 90%, and the healing time from surgery is 3-6 weeks. Eye medications will be continued for several weeks to decrease pre-existing inflammation of the conjunctiva and gland. The most common potential complication from surgery is re-prolapse of the tear gland. Breeds such as English Bulldogs and Neopolitan Mastiffs are at higher risk for recurrence. Typically this necessitates a second surgery, and the combination of 2 or more techniques to help secure the gland in position.