Thygeson lecture. Amniotic membrane transplantation: why is it effective?

PURPOSE

To review the uses and previously proposed mechanisms of action of amniotic membrane transplantation (AMT) and to suggest a new mechanism of action for the effectiveness of AMT in resolving a persistent epithelial defect (PED).

METHODS

Significant clinical and experimental publications are reviewed.

RESULTS

Evidence from the scientific literature suggests a new hypothesis for the effectiveness of AMT in the reepithelialization of a PED and the reduction of corneal stromal inflammation and continued fibrosis.

CONCLUSION

It is suggested that reepithelialization of a PED, and hence the reduction of stromal inflammation and continued fibrosis following reepithelialization, is aided by the combination of oxygenation, moisture and protection of the fragile epithelium by the amniotic membrane.

Evolution of wound dressings and their effects on the healing process

Over the last decade, there has been a rebirth of interest in wound healing research, partly due to advances in biotechnology leading to the feasibility of producing large quantities of pure, human growth factors thought to be important in the healing process and also due to the recognition that certain new dressing materials have a favorable impact in wound healing. This paper describes some of the newer dressing materials and discusses the basis for the biological effects of these products. As progress continues, it is likely that future approaches will combine the use of dressings with drugs or active agents selected to prevent or treat infection, start or stimulate the healing process, or control the production of scar tissue.