World Ophthalmology Congress 2010
[Mai 21, 2010]
Precut technique for lamellar cornea grafts
An fs-laser
microkeratome will allow cleanroom preparation of planoparallel and very thin
keratoplasty before surgery. This promising method for tissue banks will be
presented on 6th of June at the World Ophthalmology Congress 2010 in
Berlin.
In Germany alone, eight thousand people need a cornea-transplantation per year. The tissue banks are not able to satisfy this high demand for donor tissues. Many patients with affection of the corneal endothelium, hence threatened by reduced vision or even blindness, have to wait several months until help is possible.
Within an ongoing project cooperation between the Deutsche Gesellschaft fuer Gewebetransplantation (DGFG) and the Rowiak GmbH, ophthalmologists from Hannover Medical School test a new pre-operative method that serves to create a lamella from the posterior layer of a donor cornea with an exact geometrical shape. Afterwards, the remaining donor cornea is still available in the tissue banks for a second graft.
Until now, there are mainly two grafting-techniques for posterior cornea lamellae: the so called DSAEK (Descemet Stripping Automated Keratoplasty) and DMEK (Descemet Membrane Endothelial Keratoplasty). In DSAEK, corneal layers of 100 to 150 micrometer thickness are generated by using a mechanical microkeratome during surgery.During this process, abberations in thickness and Configuration of the lamella cannot be avoided. Therefore, post-operative changes of refraction and detachement of the foreign tissue are possible.
In contrast, the physicians in Hannover focus on the use of a laser microkeratome. They cut the donor cornea in a laboratory environment under cleanroom conditions. According to Dr. Lutz Blomberg, head of the Cornea Bank Hannover, the advantages are enormous: “With this precut-procedure, we win a much higher certainty of creating a really good graft. We are able to determine the exact cutting depth and we have the possibility of quality inspection after lamellation”, explains the Ophthalmologist. Furthermore, the cleanroom conditions guarantee aseptic grafts, which can be produced by tissue banks themselves and be sent to the surgery teams without any loss in quality.
This innovative operation technique is enabled by a new microkeratome based on femtosecond laser technology. The “CorneaSurgeon”, developed by co-operation partner Rowiak GmbH, allows a very precise cutting depth of less than 100 micrometers with an aberrance of 5 micrometers. Assisted by integrated imaging in terms of OCT (Optical Coherence Tomography), a real-time quality control within the cutting process is conducted. Thus, optimally adapted layer geometries for the patient can be generated.
The requirement to use this method in clinical practice will be fulfilled by completion of the cleanroom at the end of this year.
The newest results of the Hannover cornea project will be presented by Dr. Lutz Blomberg on the 6th of June during the World Ophthalmology Congress (speech No. SU-75-07). At the pavilion of DGFG (hall 12, booth A/17), there will be the chance to detailed information about the “CorneaSurgeon” during the congress (4 - 8 June 2010). According to Rowiak, the market launch of the microkeratome will be in 2011.
The co-operation between DGFG and Rowiak is funded by the foundation “Zukunfts- und Innovationsfonds Niedersachsen”.
Picture above:
With the laser-microkeratome by Rowiak, a femtosecond-laser cuts the cornea shortly above the endothelium. The distance to the endothelium is eligible by OCT-control.
For further information, please contact our co-operation partners:
Contact DGFG:
Deutsche Gesellschaft fuer Gewebetransplantation gGmbH
Martin Boergel
Feodor-Lynen-Str. 21
30625 Hannover
Tel. +49 (511) 0511 563 559-30
Fax: +49 (511) 563 559-55
E-Mail: info@gewebenetzwerk.de
Scientific Manager:
Hornhautbank Hannover
Medizinische Hochschule Hannover
Dr. Lutz Blomberg
Carl-Neuberg-Str. 1
30625 Hannover
Tel:+49 (511) 532 – 3800
Fax: +49 (511) 532 – 3050
E-Mail: LJBlomberg@aol.com