Biomechanical properties of the human cornea.

Blindness caused by diseases of the cornea can be treated by transplantation of a donor cornea. The traditional procedure consists of replacing the entire cornea of the patient by suitable donor tissue, which is called penetrating corneal transplantation. Recovery of a satisfactory vision is slow (12-18 months) and is often accompanied by many complications. Generally, the final improvement is rather limited.

Only after the development of alternative minimally invasive surgery techniques at the Netherlands Institute for Innovative Ocular Surgery (NIIOS) in Rotterdam, a spectacular improvement of the clinical outcome after corneal transplantation could be obtained. With these so called lamellar transplantation techniques, only the affected part of the cornea is replaced, i.e.a thin layer of the cornea is transplanted, thereby circumventing most of the usual complications that may arise after traditional penetrating corneal transplantation. With the latest of the lamellar transplantation techniques, a rapid (less than 1 month) and often complete recovery of vision can be achieved. Today, the lamellar transplantation techniques have found worldwide approval and application.

At NIIOS research is ongoing to further improve these revolutionary surgery techniques. Part of this research program focuses on the properties of the different transplantable parts of the cornea such as the Descemet membrane (DM) with endothelial cells and the Bowman layer ( BL). The Bowman layer is located in the anterior part of the cornea, just below the epithelium and may be replaced in ocular defects that affect that part of the cornea. The Descemet membrane and endothelium are located at the posterior part of the cornea and the function of the latter is to keep the cornea transparent. Dysfunction of the endothelial cells is an indication for transplantation in which only this affected part of the cornea is replaced, called Descemet Membrane Endothelial Keratoplasty (DMEK). In addition to research into the biochemical and biological properties of these thin membranes (DM approx.16 and the BL 10-15 µm thick) we are interested in their biomechanical properties such as stiffness and elasticity. This knowledge should help us to improve the surgical technique and to increase the number of successful interventions. 

Contact: 

Dr. Gerrit R.J. Melles

http://www.amnitrans.nl/content.php?na=77