ISSN 2398-2977      

Cornea: corneoconjunctival transposition - graft

pequis
Contributor(s):

Tim Knott

Johana Premont

Synonym(s): CCT, Keratoplasty


Introduction

  • Autologous, partial thickness, lamellar corneal graft. Sliding pedicle of peripheral cornea and conjunctiva or peripheral cornea and sclera is grafted into the axial cornea.
  • To provide tectonic, structural support to a deeper corneal defect (such as deep stromal ulcer, descemetocele).
  • Vascular supply is also provided to the surgical site with a CCT.

Uses

  • Indicated for axial stromal defects <30% of the corneal diameter.
  • Indicated in central, deep or perforated corneal lesions with sufficient peripheral healthy cornea   Cornea: descemetocele 01    Cornea: laceration / perforation  .

Advantages

  • Provides stronger tectonic support than a conjunctival flap while maintaining a healthy vascular supply to the corneal lesion.
  • Vascular supply provides a source of growth factors, fibroblasts to the corneal lesion.
  • Use of 'self' tissue eliminates the risk of graft rejection and the need for corneal tissue donor.
  • May decrease corneal scarring that occurs with a homologous corneal graft.

Disadvantages

  • Can only be partial thickness graft, therefore it is not a suitable technique when full thickness corneal donor tissue is required.
  • Only specific areas of corneal tissue adjacent to the lesion can be used.
  • Damages normal, healthy peripheral corneal tissue.
  • Ventral conjunctiva is more difficult to dissect due to the attachments to the third eyelid and a dorsal graft should be preferred whenever possible.
  • Tectonic support is not as strong as with full thickness homologous corneal graft.
  • Not suited for large corneal defects as the distance from the peripheral edge of the lesion must be at least 1 mm larger than the diameter of the corneal lesion itself.
  • Does not provide viable endothelium in case of penetrating corneal lesions.

Requirements

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Preparation

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Procedure

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Aftercare

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Outcomes

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Prognosis

  • If technically correct and the disease process is controlled, the majority of corneal lesions will heal with the above techniques.
  • Scars will form at the ulcer site.
  • Intraocular synechiae   Eye: anterior synechia - post-corneal penetration  may interfere with pupillary movement.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • de Linde Henriksen M et al (2013) Equine deep stromal abscesses (51 cases - 2004-2009) - Part 1: the clinical aspects with attention to the duration of the corneal disease, treatment history, clinical appearance, and microbiology results. Vet Ophthal 17Suppl 1, 6-13 PubMed.
  • de Linde Henriksen M et al (2013) Equine deep stromal abscesses (51 cases - 2004-2009) - PART 2: the histopathology and immunohistochemical aspect with attention to the histopathologic diagnosis, vascular response, and infectious agents. Vet Ophthal 17Suppl 1, 14-22 PubMed.
  • Martins B C et al (2013) Light microscopic evaluation and scanning electron microscopic analysis of horse eyes following deep anterior lamellar keratectomy. Vet Ophthal 16Suppl 1, 42-51 PubMed.
  • Henriksen Mde L et al (2012) Visual outcome after corneal transplantation for corneal perforation and iris prolapse in 37 horses: 1998-2010. Equine Vet J Suppl (43), 115-119 PubMed.
  • Brooks D E (2010) Targeted lamellar keratoplasty in the horse: a paradigm shift in equine corneal transplantation. Equine Vet J Suppl (37), 24-30 PubMed.
  • Plummer C E et al (2009) The use of amniotic membrane transplantation for ocular surface reconstruction: a review and series of 58 equine clinical cases (2002-2008). Vet Ophthal 12,Suppl 1, 17-24 PubMed.
  • Brooks D E et al (2008) Corneal transplantation for inflammatory keratopathies in the horse: Visual outcome in 206 cases (1993-2007). Vet Ophthal 11 (2), 123-133 PubMed.
  • Ollivier F J et al (2006) Amniotic membrane transplantation for corneal surface reconstruction after excision of corneolimbal squamous cell carcinomas in nine horses. Vet Ophthal (6), 404-413 PubMed.
  • Denis H M (2004) Equine corneal surgery and transplantation. Vet Clin North Am Equine Pract 20 (2), 361-380, vi-vii VetMedResource.

Other sources of information

  • Clode A & Matthews A (2011) Diseases and Surgery of the Cornea. In: Equine Ophthalmology. 2nd edn. Ed: Gilger B C. Elsevier Saunders, Maryland Heights, MO. pp 181-266

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