Towards a Bionic Eye

Roberto Saracco July 20, 2018 Blog 949 Views

Schematics of the process leading to the printing of a human cornea. Credit: Newcastle University

Progress towards fixing eye problems and eventually augmenting the eye and sight capabilities, including the possibility of “seeing” bits, are on the way in many research centres through the use of different technologies, each one progressing its own way and all converging into delivering new solutions.

Let’s look at a few examples.

A cockroach insect (A) with an attached artificial mechanosensory nerve was used in this experiment. The artificial afferent nerve (B) was connected to the biological motor (movement) nerves of a detached insect leg (B, lower right) to demonstrate a hybrid reflex arc (such as a knee reflex). Applied pressure caused a reflex movement of the leg. A force gauge (C) was used to measure the force of the reflex movements of the disabled insect leg. Credit: Yeongin Kim (Stanford University), Alex Chortos(Stanford University), Wentao Xu (Seoul National University), Zhenan Bao (Stanford University), Tae-Woo Lee (Seoul National University)

At Newcastle University researchers have successfully developed a process to 3D print a human cornea.
This is important since there are 10 million needing a cornea transplant because of diseases like trachoma that lead to blindness plus 5 million needing a transplant after having damaged their cornea through scratching, burns…
The possibility of creating an artificial cornea is therefore important. The researchers at Newcastle took stem cells from a donor (these can be multiplied so that in principle we can have an unlimited supply of them) and mixed them with collagen and alginate creating a bio-ink. This was used to feed the 3D printer to create the cornea. The shape of the cornea can be defined with very high precision by using a 3D scanning of the patient cornea and replicating it exactly in the printing process.

By using a laser doctors can change the refractive properties of the cornea, thus overcoming myopia. (Left) Corneal shape before (top) and after (bottom) the treatment. (Right) Simulated effects on vision. Credit: Sinisa Vukelic/Columbia Engineering
At Columbia University, Engineering faculty, researchers have discovered that by using laser it is possible to alter the biochemical and bio-mechanical tissue properties of the cornea, thus making possible to correct myopia without an invasive procedure. Today if you want to correct myopia and don’t want to use glasses you can have surgery to replace your eye lens or you can have laser refractive surgery. This latter, however, is not an option for people with a thin cornea, or dry eye, and replacing your eye lens (although a very straightforward and painless procedure – I had it) is not something you can do over and over.
The new method developed at Columbia can also be applied to correct other visual problems, like hyperopia and astigmatism (including irregular astigmatism).