Corneal Grafts

Eye Banks

• Moorfields
• East Grinstead
• Manchester
• Bristol

Consent to donation

• Must be respected if given by a person (cannot be over-ridden) but may also be granted by a nominated representative
• Donors must be informed that not every cornea is useable but that this cannot be known until the tissue is collected

Indications

• Optical

  • Bullous keratopathy
  • Keratoconus
  • Corneal dystrophy
  • Scarring
  • Failed grafts

• Tectonic

  • Perforation
  • Thinning

• Therapeutic

  • Infective keratitis

Eye retrieval

• Enucleation can be undertaken up to 24 hours after death
• Blood samples must be taken within 24 hours too
• Must be undertaken by a competent person
• Must confirm consent and check all relevant sources of information
• NHS Blood and Human Tissue Transport Box
• Donor identification: using wrist/angle tag

Poor prognostic factors

• Ocular inflammation
• Corneal vascularisation
• Glaucoma
• Ocular surface disease/lid abnormality

Contraindications to donation

• Systemic disease

  • CNS

    • CJD
    • CMV encephalitis

  • Infections

    • Rubella
    • Rabies
    • Hepatitis
    • AIDS
    • Syphilis

  • Malignancy

    • Leukaemia
    • Lymphoma
    • Metastatic malignancies otherwise

• Ocular disease

  • Previous intraocular surgery
  • Glaucoma
  • Iritis
  • Intraocular tumours

• Age

  • <1 year old: corneas too small/friable

• Severe haemodilution pre-mortem

Complications

• Early

  • Wound leak: hypotony
  • Raised IOP: retained viscoelastic, pupil block
  • Persistent epithelial defect
  • Endophthalmitis
  • Disease recurrence
  • Graft failure

• Late

  • Rejection
  • Infection
  • Disease recurrence
  • Astigmatism
  • Persistent iritis (Urrets-Zavalia syndrome with fixed dilated pupil)
  • Late failure
  • Glaucoma

• Other

  • Cataract
  • RD
  • Expulsive haemorrhage
  • CMO

Higher risk of graft rejection

• Younger patient
• Blood group incompatibility: Collaborative Corneal Transplant Study found that blood group matching may reduce risk of graft failure
• Repeat graft
• Large graft
• Eccentric graft
• PAS
• Exposed sutures
• Deep stromal vascularisation
• Pre-existing glaucoma
• Ocular surface disease
• Iritis

Graft rejection

• Type 4 immune reaction

• Typically occurs after 2 weeks post-op

• Epithelial

  • Epithelial rejection line: lymphocytes
  • Quiet eye

• Subepithelial rejection

  • Nummular infiltrates

• Stromal rejection

  • Symptomatic: reduced vision, red eye, pain
  • Anterior chamber activity
  • Stromal oedema

• Endothelial rejection

  • Khodadoust line

Management of graft rejection

• Should be suspected early, especially in any graft patient with intrao-ocular inflammation
• May be challenging to manage
• Intensive topical steroids
• Consideration of systemic steroids (including IVMP) if severe/worsening rejection or especially if evidence of endothelial rejection