■ Corneal substitutes are needed to address the shortage of human donor tissues and the current disadvantages in some clinical
indications, including immune rejection
■ Substitutes have been designed to replace part of or the full thickness of damaged or diseased corneas. They range from
prostheses, known as keratoprostheses (KPros), through naturally fabricated, cell-based, tissue equivalents, to tissue-engineered
scaffolds that serve as templates for the regeneration of host tissues
■ At present, widely accepted substitutes are not available although prostheses (KPros) have been in clinical testing or in
limited clinical use
■ The trends toward replacement of only damaged portions of the cornea and replacement of the epithelium by corneal limbal
cell transplant has been gaining momentum
■ Corneal substitutes that encourage regeneration of the host tissue may likely overcome the rejection problems and other
postoperative complications of donor tissue transplantation and KPros
■ There will probably not be a single “onesize- fits-all” corneal substitute for all indications. Instead, a small range of
corneal substitutes that are tailored to different clusters of clinical indications will be available