Eyes are truly amazing things. Even the most sophisticated video
cameras can't compete with them. They allow us to see thousands of
colours, the finest details and instantly switch our focus from
objects a just few centimetres in front of us to miles away. We
take this for granted, but sometimes eyes need a helping hand when
things go wrong.
What goes wrong?
Damage to the cornea is the second biggest cause of blindness,
affecting around 10 million people. The cornea is the transparent
layer at the front of the eye that lets light pass through the
pupil to the lens and the retina.
If the cornea stops being transparent the eye is said to have a
cataract. The cornea does a bit more than just acting as a
transparent window; it also bends or refracts the light. If the
cornea hasn't done its bit to bend light, the eye will never be
able to focus and the world will always be a blur.
Up until now the only really effective treatment for a cataract
is a cornea transplant. But this type of transplant has two main
problems:
- Supply: every cornea transplant requires a cornea donor, but
there is a shortage of donors
- Rejection: any transplanted organ is seen by the body as a
foreign object, so the immune system tries to destroy it
There may be an answer
A team of Swedish scientists have created a synthetic cornea
made of collagen. Collagen is a very strong and flexible protein
and found in tissues like tendons, ligaments and skin.
Scientists made the synthetic cornea using yeast cells
genetically implanted with human DNA sequences to produce the
collagen. The synthetic cornea is such a good copy that the body
thinks it is its own and doesn't reject it. This is seriously
clever stuff. Even the nerve cells around it grow back, so that the
whole cornea is regenerated. It actually becomes sensitive to touch
and is able to produce tears.
So far, ten patients have received the synthetic cornea. They
were all able to see again and none have developed complications.
This is very rare in any complex medical treatment.
It is still early days, but fingers crossed. Is it going to be
as significant as we hope? Only time will tell. Larger studies will
have to done to make sure the results are truly as good as they
seem.
Did you know…
The human eye is so sensitive that in total darkness it can
detect a candle at a distance of 12 kilometres!
The human eye can distinguish between over 500 shades of grey! I
didn't know there were so many different shades...