What is cherry eye?
Cherry eye is the colloquial term for prolapse of the nictitating membrane gland (third eyelid gland). The third eyelid is a protective membrane in the inner (nasal) corner of the eye. It contains a lacrimal gland that produces 30–40 % of the total tear volume. When the connective tissue anchoring this gland weakens or tears, the gland slips out of position and becomes visible as a round, red mass — resembling a cherry — in the inner corner of the eye.
Most commonly affected breeds
Breed predisposition points to a genetic basis (connective tissue laxity):
- English Bulldog, French Bulldog, Beagle, Cocker Spaniel, Basset Hound, Boston Terrier.
- Lhasa Apso, Shih Tzu, Pekingese.
- Boerboel, Shar Pei, Newfoundland, Saint Bernard.
In brachycephalic breeds the prominent eye conformation worsens the problem. It usually appears before 2 years of age.
Symptoms
- Red, rounded, well-defined mass in the inner corner of the eye — may be unilateral or bilateral.
- Eye irritation, increased or decreased tearing.
- Frequent discharge, conjunctivitis.
- Dog pawing or rubbing the eye.
- Ulceration of the exposed gland surface if left untreated.
Treatment
Surgical repositioning: the only correct option
Removing the gland is not recommended: it eliminates 30–40 % of tear production and significantly increases the lifetime risk of dry eye (keratoconjunctivitis sicca, KCS).
The treatment of choice is surgical repositioning of the gland back to its normal location:
- Pocket technique (Morgan technique): the gland is sutured beneath the conjunctiva, creating a "pocket" that keeps it in position. Success rate 90–95 %.
- Periosteal anchoring: the gland is fixed directly to the orbital periosteum. Higher long-term success in some studies.
Recurrence occurs (5–10 %) and may require a second procedure.
When to operate?
As soon as possible. An exposed gland becomes chronically inflamed and may lose some functional capacity. Operating on fresh tissue is easier and has fewer complications than on chronically inflamed tissue.
Late dry eye (KCS)
Even after correct repositioning, some dogs with bilateral cherry eye develop mild gland hypofunction long-term. Annual Schirmer tear tests are helpful, with lubricating eye drops if values are borderline.