Cornea and External Diseases

Epithelial Defect

Epithelial defect post penetrating keratoplasty.
  • Causes: epithelial cell loss during storage, surface trauma intra-operatively, eye rubbing, lid malposition or medication toxicity.
  • Normally, the defect will re-epithelialize by the dividing and migrating host epithelium from the limbus within a week.

Clinical Features

  • Minimal to significant loss of corneal epithelial cells can be easily seen after fluorescein staining and using the cobalt blue filter.
  • Delayed epithelialization may occur in graft with an extensive epithelial defect and eyes with compromised healing ability i.e. post-chemical or radiation injury, Stevens-Johnson syndrome, ocular pemphigoid, rosacea keratitis, or chronic blepharitis with meibomian gland dysfunction.
  • Nonhealing epithelial defect may be complicated by corneal melting, thinning, perforation, infection or graft rejection.

Management

  • Routine follow-up with fluorescein to evaluate the corneal after corneal transplantation surgery is important because epithelial integrity is vital for graft survival.
  • Treatment of pre-existing eye conditions pre-operatively i.e. punctal occlusion in eyes with pre-existing dry-eyes.
  • Meticulous protection and handling of the corneal button epithelium during surgery to minimize epithelial loss / damage.
  • Bandage soft contact lens or a lateral tarsoraphy may be helpful in eyes with chronic non-healing defects.