Scientists Develop Artificial Corneas

For the first time in the history of medical science, lab-grown corneas, one that resemble the real ones and which could, in the near future, restore the sight of blind people, have been developed by scientists in the United States.

The fabricated corneas, which took five years to be developed, resemble the real ones in every important way, even mimicking human corneas in how cloudy they can get when splashed with substances such as detergents, hair conditioners and cleaning agents, according to Dr. May Griffith of the University of Ottawa Eye Institute and Dr. Mitchell Watsky of the University of Tennessee in Memphis who developed them.

Rigorous tests conducted on each of the corneas also showed that they resembled human corneal tissue in structure, biochemistry and the way they conduct electrical signals. According to the researchers, the artificial corneas can also be used for research and may save millions of animals from cosmetic or medical tests, a report in New Scientist says.

The human corneas is made up of three major cell layers and the researchers harvested cells from each of the layers from human corneas.

Thereafter, the researchers infected the cells with viruses that made them keep on dividing indefinitely, a process known as "immortalisation" which provides a continuous supply of the desired cell type.

The scientists then tested each of the tissue types rigorously, to make sure they resembled human corneal tissue in structure, biochemistry and the way they conduct electrical signals.

In order to anchor the three corneal layers, Dr. Griffith and Dr. Watsky use a synthetic scaffold, made of a mesh of collagen cross-linked with gluataraldehyde. They placed cells on top, within the underneath the scaffolding. Though the fabricated corneas were developed primarily for use in rabbi transplants, the scientists plan to take their research a little further to develop ones that could be used for human transplant.

According to the Director of Otawa Eye Institute Bruce Jackson, "This might just be the solution we need to meet future demands and restore eyesight to many blind eyes."

However, Dr. Griffith says that there is still a lot of work to be done, such as strengthening the scaffolding. "It is not mechanically strong enough. People can get poked in the eye accidentally." She says.

Earlier efforts to recreate the cornea, the human eye's transparent cover that protects the pupil and the iris from external elements and also helps to focus images on the retina, have been unable to mimic the human model accurately.