Cherry eye is a disorder of the

nictitating membrane The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. All ...

(NM), also called the

third eyelid The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. All ...

, present in the eyes of dogs and cats.Gelatt, K. N. (2000). ''Essentials of Veterinary Ophthalmology''. Baltimore: Lippincott Williams & Wilkins. Cherry eye is most often seen in young dogs under the age of two.Gelatt, K. N. (2001). ''Color Atlas of Veterinary Ophthalmology''. Baltimore: Lippincott Williams & Wilkins. Common misnomers include adenitis, hyperplasia, adenoma of the gland of the third eyelid; however, cherry eye is not caused by hyperplasia, neoplasia, or primary inflammation.Slatter, D. (2001). ''Fundamentals of Veterinary Ophthalmology'': Third Edition. Philadelphia: W.B. Saunders Company. In many species, the third eyelid plays an essential role in vision by supplying oxygen and nutrients to the eye via tear production.Robledo, E. P., Serrano, R. D., Sanches, N. Q., & Ramirez, A. M. (n.d.).
Effect of Pet Vision in a Canine with Keratoconjunctivitis Sicca (Dry Eye)
". Retrieved 1 December 2012. Normally, the gland can turn inside-out without detachment. Cherry eye results from a defect in the retinaculum which is responsible for anchoring the gland to the periorbita. This defect causes the gland to

prolapse In medicine, prolapse is a condition in which organs fall down or slip out of place. It is used for organs protruding through the vagina, rectum, or for the misalignment of the valves of the heart. A spinal disc herniation is also sometimes call ...

and protrude from the eye as a red fleshy mass. Problems arise as sensitive tissue dries out and is subjected to external trauma Exposure of the tissue often results in secondary inflammation, swelling, or infection. If left untreated, this condition can lead to

dry eye syndrome Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range ...

and other complications.

Description

Cherry eye is most common in young dogs, especially breeds such as

Cavalier King Charles Spaniel The Cavalier King Charles Spaniel is a British breed of toy dog of spaniel type. Four colours are recognised: Blenheim (chestnut and white), tricolour (black/white/tan), black and tan, and ruby; the coat is smooth and silky. The lifespan is usual ...

English Bulldog The Bulldog is a British breed of dog of mastiff type. It may also be known as the English Bulldog or British Bulldog. It is of medium size, a muscular, hefty dog with a wrinkled face and a distinctive pushed-in nose.Lhasa Apso The Lhasa Apso ( ) is a non-sporting dog breed originating in Tibet. It has traditionally been used as an interior sentinel. Etymology Lhasa is the capital city of Tibet, and ''apso'' is a word from the Tibetan language. There is some deba ...

Shih Tzu The Shih Tzu (, ; literally " Hsi Shih dog") is a toy dog breed originating from Tibet and was bred from the Pekingese and the Lhasa Apso. Shih Tzus are known for their short snouts and large round eyes, as well as their long coat, floppy ear ...

West Highland White Terrier The West Highland White Terrier, commonly known as the Westie, is a breed of dog from Scotland with a distinctive white harsh coat with a somewhat soft white undercoat. It is a medium-sized terrier, although with longer legs than other Scott ...

Pug The Pug is a breed of dog originally from China, with physically distinctive features of a wrinkly, short-muzzled face and curled tail. The breed has a fine, glossy coat that comes in a variety of colors, most often light brown (Fawn (colour) ...

Bloodhound The bloodhound is a large scent hound, originally bred for hunting deer, wild boar and, since the Middle Ages, for tracking people. Believed to be descended from hounds once kept at the Abbey of Saint-Hubert, Belgium, in French it is called, ''l ...

American Cocker Spaniel The American Cocker Spaniel is a breed of sporting dog. It is a spaniel type dog that is closely related to the English Cocker Spaniel; the two breeds diverged during the 20th century due to differing breed standards in the US and the UK. In th ...

, and

Boston Terrier The Boston Terrier is a breed of dog originating in the United States of America. This "American Gentleman" was accepted in 1893 by the American Kennel Club as a non-sporting breed. Color and markings are important when distinguishing this breed f ...

. Cherry eye is rare in felines, but can occur. This defect is most common in the Burmese breed of felines.Griffin, C., & Glaze, M. B. (2008). "Eyes and Ears". St John U.S.V.I. November 3–6. International Veterinary Seminars. A similar condition exists in dwarf lop-eared rabbits, which occurs in the

harderian gland The Harderian gland is a gland found within the eye's orbit that occurs in tetrapods (reptiles, amphibians, birds and mammals) that possess a nictitating membrane. The gland can be compound tubular or compound tubuloalveolar, and the fluid it s ...

. Similar surgical treatment is necessary. There is likely a complicated and multigenic component involving genetic risk factors. Some breeds are considered to be more susceptible to its development than others, including the Bulldog, Boston Terrier, Bull Terrier, Lhasa Apso, Cocker Spaniel, St. Bernard, Shar-pei, Shih Tzu and Poodle The NM contains many glands which merge and appear as a single gland.Sarma, B. (2010). "Cherry Eye in Dogs. ''Intas Polivet'', 11, pp. 80–81. Typically, glands secrete tears for lubrication of the cornea. Lack of anchoring allows the gland to flip up, causing the gland to prolapse. Symptoms include a visible fleshy mass, abnormal tear production, and a discharge or drainage from the eye. Cherry eye is typically diagnosed by examination of the

conjunctiva The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium ...

and

. The most obvious symptom of cherry eye is a round fleshy mass in the medial

canthus The canthus (pl. canthi, palpebral commissures) is either corner of the eye where the upper and lower eyelids meet. More specifically, the inner and outer canthi are, respectively, the medial and lateral ends/angles of the palpebral fissure. Th ...

of the eye, similar in appearance to the fruit it is named for. This mass may be unilateral or ‘’bilateral’’. Both eyes may develop cherry eye at different times in the animal's life. Other symptoms of cherry eye include drainage from the eye and abnormal tear production. Initially, cherry eye results in overproduction of tears, but eventually changes to unsubstantial tear production.

Treatment

Non-surgical

Cherry eye, if caught early, can be resolved with a downward diagonal-toward-snout closed-eye massage of the affected eye or occasionally self-corrects alone or with antibiotics and steroids. Sometimes the prolapse will correct itself with no interference, or with slight physical manual massage manipulation as often as necessary coupled with medication.

Surgical

Surgery is the most common means of repairing a cherry eye. Surgery involves gland replacement, not excision, by anchoring the membrane to the orbital rim or using a pocket technique. In severely infected cases, preoperative antibiotics may be necessary by means of antibiotic eye ointment. Removal of the gland was once an acceptable treatment, and made the eye appear completely normal. Despite cosmetic appeal, removal of the gland reduces tear production by 30 percent. Tear production is essential in maintaining and protecting the eye from the external environment. Reduced tear production is especially problematic in breeds of animals predisposed to

Keratoconjunctivitis sicca Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range ...

(KCS), also known as dry eye syndrome. With surgeries performed in this manner, KCS often results later in life. Cherry Eye in Small Mixed Breed Dog

KCS is not common in dogs, affecting one per cent of the dog population.Blount, W. (n.d.).
Dry Eye: More formally known as Keratoconjuntivis Sicca or KCS
. Retrieved 1 December 2012. KCS is a chronic degenerative conjunctivitis that can lead to impaired vision and blindness. KCS has a wide array of causes including drug toxicity, cherry eye, previous surgery, trauma, and irradiation. KCS can be treated, but treatment often spans the entirety of the animal's life. In contrast to this, several replacement surgical procedures exist to remedy cherry eye. Replacement of the gland results in lower instances of dry eye later in life.Plummer, C., Kallberg, M., Gelatt, K., Gelatt, J., & Barrie, K. P. (2008). "Intranictitans tacking for replacement of prolapsed gland of the third eyelid in dogs". ''Veterinary Ophthalmology'', pp. 228–233. Surgery types are broken into two groups: anchoring procedures and pocket/envelope procedures. At least 8 surgical techniques currently exist. In anchoring procedures, the prolapsed gland must be sutured to the periorbital fascia, the

sclera The sclera, also known as the white of the eye or, in older literature, as the tunica albuginea oculi, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some crucial elastic fiber. In humans, and som ...

, or the base of the

. In contrast, pocket procedures involve suturing healthy tissue around the prolapsed to enclose and secure it. Each of these techniques may be performed with an anterior or superior approach, depending on which direction of suturing will cause the least complications to the eye.

Anchoring method

Originally, the anchoring method involved suturing the gland to the globe. This method was superseded over time due to the risky and difficult nature of the surgery, along with a high rate of recurrence. Anchoring approaches from posterior may disrupt normal fluid excretion. Subsequently, an anterior approach was introduced. Disadvantages of anchoring techniques include restricted mobility of third eyelid, which is essential in the functions of fluid distribution and self-cleaning. New procedures are currently being explored to allow tacking of the NM without restricting movement of the third eyelid. Few studies compare results of surgeries, therefore choosing a procedure is a matter of preference.

Envelope/pocket method

The envelope method, often called the pocket technique, requires suturing of tissue around the prolapse, encasing it in a layer of conjunctiva. Pocket techniques are easiest for doctors to learn. Pocket methods also have anterior and posterior versions. Posterior suturing techniques are the most commonly used because they cause the least complications, with no alterations in tear production. Surgery should only be attempted by experienced surgeons. Inappropriate surgical techniques can result in many complications including cysts on the eye.

Prognosis

Without treatment

Previously, treatment was thought optional until the role of NM was fully understood. The NM gland is responsible for 40–50% of tear production. If exposed for extended periods of time, the gland is at risk for trauma, secondary infection, and reduced tear production. Many complications can arise if left untreated: early closed-eye massage manipulation is recommended to prevent inflammation .

Post treatment

Postoperative treatment includes antibiotic eye ointment three times daily for two weeks. It is possible to have a relapse of the gland after surgery and require multiple surgeries. With treatment, it is possible for animals to live a normal life.

References

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External links

''Cherry Eye'' from The Pet Health Library
Dog diseases Eye diseases