Overview

• Inversion of part or all of one or more eyelid margins.
• Frictional irritation of the cornea, because of contact by the eyelashes or eyelid hair, may result in corneal ulceration or perforation or pigmentary keratitis.
• Ophthalmic system (vision may be threatened).

Signalment

• Common in dogs; occasionally seen in cats.
• Cats-usually seen in brachycephalic breeds (e.g., Persian and Himalayan).
• Dogs-seen in chow chow, shar-pei, Norwegian elkhound, sporting breeds (e.g., spaniel, retriever), brachycephalic breeds (e.g., English bulldog, pug, Pekingese), toy breeds (e.g., poodle, Yorkshire terrier), and giant breeds (e.g., mastiff, Saint Bernard, Newfoundland).
• Age-seen in puppies as early as 2–6 weeks old (especially chow chow and shar-pei); usually identified in dogs <1 year old; may be seen in any age cat.

Signs

• Depends on type and degree of condition.
• Mild, medial-chronic epiphora and medial pigmentary keratitis (toy dogs and brachycephalic dogs and cats).
• Mild, lateral-chronic mucoid to mucopurulent ocular discharge (giant-breed dogs).
• Upper lid, lower lid, or lateral canthal-severe blepharospasm, purulent discharge, pigmentary or ulcerative keratitis, and potential cornea rupture (chow chows, shar-peis, bloodhounds, and sporting breeds).

Causes & Risk Factors

• Primarily genetic predisposition based on facial conformation and eyelid support.
• Brachycephalic breeds (dogs and cats)-excessive tension on the ligamentous structures of the medial canthus coupled with nasal folds and facial conformation defects results in rolling inward of the medial aspects of the upper and lower eyelids at the medial canthus.
• Giant breeds and breeds with heavy/loose facial skin (bloodhounds) or excessive facial folds (chow chows, shar-peis)-laxity of the lateral canthal ligamentous structures allows for entropion of the upper and lower eyelids and the lateral canthus.
• Chronic infectious conjunctivitis or keratitis (cats)-may lead to functional entropion caused by chronic blepharospasm (spastic entropion).
• Predisposed breeds (dogs)-spastic entropion, if ocular irritation (e.g., distichia, ectopic cilia, trichiasis, foreign body, and irritant conjunctivitis) leads to excessive blepharospasm.
• Non-predisposed breeds-may be the result of a primary irritant causing secondary spastic entropion.
• Severe weight loss or muscle atrophy caused by masticatory myositis (dogs)-loss of orbital fat or periorbital musculature may lead to enophthalmos and entropion.

Differential Diagnosis

• Usually obvious clinically-underlying causes of spastic entropion (lash anomalies, foreign bodies, infectious keratitis/conjunctivitis) should be ruled out and corrected, if possible, before an attempt at surgical correction is made.
• Puppies-common for first-time breeders of chows and shar-peis to mistakenly think that the eyelids have not opened at 4–5 weeks of age, when puppies actually have severe blepharospasm and spastic entropion.

CBC/Biochemistry/Urinalysis

N/A

Other Laboratory Tests

N/A

Imaging

N/A

Diagnostic Procedures

Application of a topical anesthetic may reduce spastic component and allow for differentiation of spastic versus physiologic entropion.

Puppies

• Young (especially shar-peis and chows)-do NOT initially perform skin resection surgery.
• If cornea is ulcerated-topical antibiotic (e.g., neomycin/polymyxin B/bacitracin) ointment q6–8h.
• If mildly entropic and cornea not ulcerated, lubricate with artificial tear ointment q8–12h.
• If moderate to severe entropion, temporarily evert eyelid margins with sutures to try to break the spasm-irritation-spasm cycle; if successful, permanent procedure is unnecessary. May need to be repeated every 2–4 weeks until an adult facial conformation is achieved.
• Permanent skin resection technique-postponed until patient's facial conformation matures (usually 6 months of age in most breeds), as this increases success rates.

Medial Entropion

• Temporary eversion of the medial canthus with sutures may aid in determining the contribution of medial entropion to epiphora in toy dog breeds and brachycephalic dogs/cats.
• Medial canthal reconstruction should be performed if the entropion results in pigmentary keratitis, chronic epiphora, or corneal scarring.

Mature Dogs and Cats

• Chronic entropion-requires some type of eyelid margin–everting surgery; ranges from simple Hotz-Celsus procedure or more radical lateral canthoplasty procedures.
• No history of previous entropion and clinical signs of acute condition-examine meticulously for cause of spastic condition and correct; may attempt a temporary eversion suture technique before performing permanent skin resection, if necessary.

Drug(s)

• Topical ophthalmic ointment-triple antibiotic or antibiotic based on culture and sensitivity testing of corneal ulcer bed/conjunctival surfaces; q6–12h; may be used if the cornea is ulcerated, postoperatively, or as a presurgical lubricant.
• Topical petrolatum-based artificial tear ointments (Duratears, Puralube, or Lacrilube) q8–12h may be used temporarily in mild cases in which the cornea is not ulcerated.

Contraindications/Possible Interactions

N/A