Impressive success in regeneration of eye lenses with stem cells

A team from the Sun Yat-sen University and the University of California, San Diego has developed a procedure to regenerate the eye lens and successfully applied it on children with cataracts in China. Normally an implanted lens is  needed to restore sight, but the new procedure activated stem cells in the eye to grow a new one. About 20 million people are blind because of cataracts, which become more common with age.

The procedure removes the cloudy cataract from the inside of the lens via a tiny incision and importantly leaves the lens capsule on the outer-side intact.

The structure on the inside is lined with lens epithelial stem cells, which normally repair damage. The scientists have created a procedure to preserve these cells while at the same time removing the native lens. After success with rabbits and monkeys were successful,  the approach was trialed in 12 children. Within eight months the regenerated lens was back to the same size as normal.

Four to five weeks after surgery, the regenerating lens tissue grew from the periphery of the capsular bag towards the center in a curvilinear symmetrical pattern.Seven weeks after surgery, the regenerating lens tissue formed a transparent biconvex lens comparable to a normal healthy lens . The refractive power of the regenerated lenses after surgery was evaluated and found to have increased to an average of 15.6 dioptres from the first to the fifth month after surgery, a value comparable to that of a normal lens 16.

Dr Kang Zhang, one of the researchers, commented: “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.”

The procedure was tried in children because their lens epithelial stem cells are more youthful and more able to regenerate than in older patients. Dr Zhang says tests have already started on older pairs of eyes and says the early research “looks very encouraging”.

Dr Zhang believes that targeting stem cells already sitting in the eye could have “great potential” for treating a wide range of diseases from macular degeneration to glaucoma.

One of the researchers, Prof Andrew Quantock, said: “Our work not only holds potential for developing cells for treatment of other areas of the eye, but could set the stage for future human clinical trials of anterior eye transplantation to restore visual function.”

You can find the study here. Healthy living into very old age just came another step closer

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