Cataracts is pretty common, you probably know of someone who has suffered or is suffering with it. In fact it is the leading cause of blindness in the world. It is occurs when the part of the eye called the lens (the bit that, in conjunction with the muscular iris or coloured bit of your eye, helps focus what you are seeing) changes and becomes less see-through. This means that your vision becomes almost misty-like. The reasons behind developing cataracts are not fully understood yet but it is thought that the change in the structure of the lens could be due to changes in the proteins found there. This happens over time and so is a condition that is more common as you get older, although having a family history, diabetes or taking a high dose of corticosteroid medication can increase your risk of developing cataracts.
Once the cataracts become too bad to be corrected with a stronger glasses prescription, the only effective treatment is then surgery. This involves removing the old, cloudy lens and then replacing it with a new, clear plastic one. Unfortunately, this does not correct your vision completely as the newly inserted lens is set to a certain prescription and this may not correct your vision completely.
There may be good news though! Researchers at at the Sun Yat-sen University and the University of California, San Diego have developed a new technique whereby the the cataract is removed from inside the lens via a tiny incision. However, unlike in traditional surgery, the outer lens known as the lens capsule is not removed. This is because this structure is lined with a type of cell known as epithelial stem cells. Stem cells as you may or may not know are regenerative cells that have the ability to grow and then differentiate in other types of cells that are needed to a specific job. In this case the Scientists hoped that these stem cells would regenerate the lens.
The team first tried this technique on rabbits and monkeys as these animals have similar eyes to our own. These were successful and so trials in 12 children with congenital cataracts were conducted in Zhongshan, china. Within 3 months of surgery a regenerated lens structure had formed and by 8 months post-surgery it had grown to the size of a normal lens. The new procedure also showed a significantly decrease in the number of complications that arose in comparison to the traditional technique.
Dr Kang Zhang, one of the researchers, told the BBC News website:
“This is the first time an entire lens has been regenerated. The children were operated on in China and they continue to be doing very well with normal vision.”
Unfortunately larger trials are needed before this technique can put into mainstream practice and further researcher into whether the same approach can be used for adult cataracts as these are slightly different in conformation. However, Dr Zhang says tests have already started on older pairs of eyes and says the early research
“looks very encouraging”.
So hopefully it won’t be too long until this technique becomes the norm!
If you are feeling extra geeky and want to read the paper for yourself, you can find it here.
Until next time…