Two types of artificial cornea are being developed in Germany, an advance that could potentially restore sight to people with corneal anomalies.
The work is being undertaken by Dr Joachim Storsberg and his team from the Fraunhofer Institute for Applied Polymer research IAP, Potsdam, in collaboration with the Aachen Centre of Technology Transfer.
Scientific partners in the ArtCornea project include the Martin Luther University of Halle-Wittenberg, ACTO eV and the Ophthalmic Clinic Cologne-Merheim.
In a statement, Storsberg said one of the corneas can be used in cases where the patient would not tolerate a donor cornea.
ArtCornea is based on a polymer with high water-absorbent properties. Storsberg and his team have added a new surface coating to ensure anchorage in host tissue and functionality of the optic.
The haptic edge was chemically altered to encourage local cell growth. These cells graft to the surrounding human tissue, which is essential for anchorage of the device in the host tissue. The researchers aimed to enlarge the optical surface area of the implant in order to improve light penetration beyond what had previously been possible.
‘Once ArtCornea is in place, it is hardly visible, except perhaps for a few stitches. It’s also easy to implant and doesn’t provoke any immune response,’ said Storsberg.
The specialists have also managed to make a chemically and biologically inert base material biologically compatible for the second artificial cornea, ACTO-TexKpro.
Dr Storsberg is said to have achieved this by selectively altering the base material, polyvinylidene difluoride, by coating the fluoride synthetic tissue with a reactive molecule.
This allows the patient’s cornea to bond together naturally with the edge of the implant, while the implant’s inner optics, made of silicon, remain free of cells and clear.
The ACTO-TexKpro is claimed to be particularly suitable as a preliminary treatment, for instance if the cornea has been destroyed as a consequence of chronic inflammation, a serious accident, corrosion or burns.
Experiments were carried out in collaboration with Dr Norbert Nass and Dr Saadettin Sel, senior consultant ophthalmologist at Martin-Luther-University Halle-Wittenberg.
TexKpro and ArtCornea were first tested by the doctors in the laboratory and then in vivo in several rabbits.
After a six-month healing process, the implanted prostheses were accepted by the rabbits without irritation.
Clinical trials are expected to commence soon at the Eye Clinic Cologne-Merheim.