Let there be light

Scientists are reporting encouraging early results using a femtosecond laser to crosslink collagen in keratoconic corneal tissue.

The Massachusetts General Hospital research team said the laser technique, known as two-photon absorption, could replace the ultraviolet light currently used to crosslink collagen fibres and stiffen the damaged cornea.

Research leader, Dr Seok-Hyun Yun, said that using ultraviolet light had drawbacks, adding: “[It] comes with a risk of damaging the innermost layer of the cornea, a complication that changes the corneal function and can cause it to become very hazy.

“There is also no way to predict whether the procedure will actually improve vision in a given patient,” he emphasised.

The research, published in the journal Optica, found that, using titanium-sapphire femtosecond lasers, the team were able to successfully crosslink collagen for ten minutes without damaging the tissue samples.

Dr Yun said that more studies were needed, and noted that the femtosecond crosslinking was a time-consuming technique. It might be most useful to address damage in a small section of the cornea, he explained.

The laser technique had previously been used to harden the liquid resins in parts for microscopes, Dr Yun highlighted.