Contributors: Dennis E Brooks, David L Williams

 Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading

Introduction

  • An outward turning of the eyelid margin, sagging of lower lid is most common form; palpebral conjunctiva is exposed.
  • Cause: congenital in some breeds.
  • Acquired often due to surgical overcorrection of entropion, senile entropion.
  • Signs: ectropion → exposure conjunctivitis Conjunctivitis or keratitis Keratitis.
  • Diagnosis: clinical examination.
  • Treatment: if needed is surgical.
  • Prognosis: good.

Presenting Signs

  • Asymptomatic (may be detected at routine veterinary examination).
  • Ocular irritation and discharge due to chronic conjunctival changes Keratitis.

Age Predisposition



Congenital (familial)
  • 2-6 months old.

Breed Predisposition



Congenital

Cost Considerations

  • Surgery may be required.
  • Referral advised.

Pathogenesis

Etiology



Congenital
  • Familial: inheritance not determined.
Acquired
  • Citatricial: previous scarring of the eyelid (including previous entropion treatment Entropion ).
  • Atonic: decreased elasticity in the skin on the top of the head → slipping down of the palpebral fissures → lower lid ectropion.
  • Paralytic: damage to the facial nerve (cranial nerve VII) which supplies muscularis orbicularis oculi and muscularis levator palpebrae superioris. Seen in combination with ptosis and facial anesthesia. Middle ear disease may be responsible.

Predisposing Factors

General
  • Disease in most dogs is secondary to breed-associated alterations in facial conformation and eyelid support. Laxity of the palpebral tissue and deficiency of the lateral retractor muscle cause ectropion. Excessive length of palpebral tissue, small globe size, relative enophthalmos, weakness of the lateral retractor muscle, and heavy facial skin folds and pendulous pinnae cause ventral ectropion.

Pathophysiology



Congenital
  • Familial: inheritance pattern not defined. Palpebral fissure too long and lax.
  • Diamond Eye: in St Bernard and Bloodhound. Notch in center of lids results in both ectropion (adjacent to notch) and entropion (adjacent to medial and lateral canthi). Entropion usually worse on upper lid, ectropion on lower lid. Difficult to surgically repair.
  • Physiological: after a hard working day - does not require treatment. Seen in the working Retriever and Setter.
Acquired
  • Cicatricial: including overcorrection of an entropion.
  • Atonic: especially English Cocker Spaniel English Cocker Spaniel. A loss of elasticity in the skin on the top of the head, combined with heavy ears → slipping of the palpebral fissures → upper lid entropion Entropion and lower lid ectropion Eyelid ectropion 03 - Clumber Spaniel.
  • Paralytic: damage to facial nerve (cranial nerve VII) causes loss of orbicularis muscle tone.
  • Neurologic: loss of orbital or periorbital mass in masticatory muscle myositis may result in ectropion.
  • Hypothyroidism: can cause ectropion bilaterally.

Timecourse

  • Time to exposure keratitis/conjunctivitis dependent on severity of ectropion.
  • Ectropion noted in predisposed breeds by 1 year of age.

Diagnosis

Presenting Problems

  • Ocular pain.
  • Red eye.
  • Mucoid to mucopurulent ocular discharge.

Client History

  • Redness of eye.
  • Asymptomatic.
  • Ocular pain.
  • Mucoid ocular discharge.

Clinical Signs

  • Lids obviously turning out.
  • Conjunctival hyperemia (red eye).
  • Visible bulbar and palpebral conjunctivae.
  • Visible hyperemic nictitans.

Diagnostic Investigation



Other
  • Fluorescein stain Fluorescein test test to rule out corneal lesion.
  • Nasolacrimal duct patent.
  • Neurologic evaluation of cranial nerves.

Differential Diagnosis

  • Masticatory muscle myositis.
  • Hypothyroidism.

Treatment

Initial Symptomatic Treatment

Standard Treatment

  • Corrective surgery is indicated if persistent conjunctivitis, tear staining and progressive corneal ulceration are present.
Many techniques
  • Wedge resection: to shorten and raise the lid Eyelid: wedge resection. This does not correct any lid laxity at the lateral canthus.
  • Khunt Szymanowski procedure: this shortens the lid and helps overcome lid laxity.
  • V-to-Y plasty: can be used to correct a cicatricial ectropion.
  • Radical face-lift surgery may be necessary in severely affected dogs.
  • Surgery may need to be combined with medical treatment for conjunctivitis Conjunctivitis.

Monitoring

  • Reduction of hyperemia and chronic conjunctivitis.
  • Recurrence of signs of corneal ulceration.

Subsequent Management

Monitoring

  • Ectopion may worsen with age.

Outcomes

Prognosis

  • Good - many cases do not require treatment. Dogs with intermittent, work- or fatigue-induced ectropion should not be surgically corrected.

Expected Response to Treatment

  • Reduction of ocular pain and hyperemia.
  • Decreasing frequency of bouts or resolution of chronic conjunctivitis.

Reasons for Treatment Failure



Standard
  • Too small a wedge resected.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Hamilton H L, McLoughlin S A, Whitley R D & Swain S F (1998) Surgical reconstruction of severe cicatricial ectopion in a puppy. JAAHA 34 (3), 212-218 PubMed.
  • Bigelbach A (1996) A combined tarsorrhaphy - canthoplasty technique for repair of entopion and ectopion. Vet Comp Ophthal 6 (4), 220-224 VetMedResource.
  • Barnett K C (1988) Inherited eye disease in the dog and cat. JSAP 29 (7), 462-475 VetMedResource.

Other sources of information

  • Gelatt K N (1999)Veterinary Ophthamology.3rd edn: Williams & Wilkins.

Other Sources of Information