Research using x-ray free-electron laser could boost synthetic lens development

A professor at Kingston University (London, England), turning to the Spring-8 angstrom compact free-electron laser (SACLA) synchrotron facility (Harima, Japan), has made a discovery about the shape of the eye that could boost the effectiveness of man-made lenses used in cataract surgery.

Research carried out by Professor Barbara Pierscionek and a team of fellow vision experts suggests that the way proteins are distributed in the lens of the eye may cause its gradient to be stepped rather than smooth as previously thought. The finding could give a new insight into the way the eye grows and lead to major improvements in synthetic lenses used in surgery to treat patients who have developed cataracts.

Artificial replacements did not currently match the quality of real ones, Professor Pierscionek said. “However this research could help give patients better vision if manufacturers use it to develop an improved lens able to change focus,” she explained.

Professor Pierscionek, the Associate Dean of Research and Enterprise at Kingston’s Faculty of Science, Engineering and Computing, has devoted two decades to researching the eye’s lens. Her work has explored its biochemical, optical, and mechanical properties. Since the lens is one of the few organs in the body that does not replenish itself, it is a model for ageing. “The lens is the key to a lot of things—we just haven’t unlocked its full potential yet. It has the capacity to tell us what has happened to a person throughout their life and their disease state,” Professor Pierscionek says.

Professor Pierscionek carried out much of her most recent research at the SACLA synchrotron facility—home of the world’s largest third-generation synchrotron. It accelerates electrons close to the speed of light to generate x-rays and other beams. The electrons are injected into a storage ring 1.4 km in diameter, with the resultant x-rays fed into experimental stations dotted around the site. “These x-rays can penetrate parts of the body and soft tissue better than other forms of radiation,” Professor Pierscionek says. “This allows engineers and scientists to look deeply into anything from metal to bacteria.” When taking measurements it was important to keep the sample as close as possible to its natural state, she says. “The synchrotron is so sophisticated that it allows us to measure the lenses while they are still in the eyeball.”

Some of the research has been conducted in collaboration with scientists from the Spring-8 facility and Cardiff University in Wales. It is being funded by eye research charity Fight for Sight as well as grants from Spring-8, which has provided use of the synchrotron.

Further analysis is now being carried out in laboratories at Kingston University. Professor Pierscionek and her team are working with Dr. Mehdi Bahram, a researcher funded by Fight for Sight, using ray tracing and mathematical modeling. The work involves projecting lasers of different colors through different parts of the lens to trace their paths. The information will then be used to help develop lenses with improved optical quality.

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