Equis ISSN 2398-2977

Eye: dermoid

Contributor(s): Dennis E Brooks, Graham Munroe

Introduction

  • Congenital masses of normal tissue growing in an abnormal site - choristomas.
  • May involve cornea, conjunctiva, third eyelid or eyelids.
  • May contain elements of skin, including hair, leading to ocular irritation.
  • Signs: degree of visual impairment depends upon extent of involvement of the eye, especially the cornea and secondary ocular disease.
  • Treatment: by surgical removal, including superficial keratectomy, is usually successful.

Pathogenesis

Etiology

  • Unknown - presumed to be due to defects in embryogenesis where elements of disordered dermal/epidermal tissue become entrapped within the cornea, conjunctiva, etc.

Pathophysiology

  • Dermoids are choristomas and are defined as normal tissue elements located at an abnormal site.
  • They may represent congenital tumors of skin and related appendage tissue.
  • Not inheritable in the horse, but seen in Standardbreds   Standardbred  and Quarterhorses   Quarterhorse  .
  • Their cause and pathophysiology are unknown.
  • Congenital mislocations of normal elements of skin involving external eye tissue.

Diagnosis

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Joyce J R et al (1990) Iridial hypoplasia (aniridia) accompanied by limbic dermoids and cataracts in a group of related quarterhorses. Equine Vet J Suppl 10, 26-28 PubMed.
  • Latimer C A et al (1985) Neonatal ophthalmology. Vet Clin N A Equine Pract (1), 235-259 (Review) PubMed.

Other sources of information

  • Brooks D E (1999) Equine Ophthalmology. In: Veterinary Ophthalmology. Ed: Gelatt K N. 3rd edn. pp 1053-1116.


ADDED