SPring 8 Synchrotron, Japan
first group in the world to conduct such research. Understanding the way proteins impact on the refractive index is only one part of this story. Another aspect is the way the lens changes shape when focusing and here Professor Pierscionek reasons a mechanical understanding of the lens is absolutely crucial. “The simple fact is,” she explains, “that when you change your
focus, from near to far for example, your lens is changing shape. If it is changing shape then it is changing the way it is distributing its proteins, and thus changing its refractive index. “This was exciting for us,” she continues, “which is why years ago
I moved my NHMRC fellowship to an engineering department because I wanted to stretch lenses to see how the change in shape affects the optics. I knew that I could not physically build an instrument myself, even though I had designed it, and needed the expertise of engineers to help me.” Some many years on, Professor Pierscionek
still works closely with engineers using sophisticated modelling tools like Finite Element Analysis (FEA). Engineers have used this modelling
technique for
“We know broadly that the lens alters the focus of the eye due to
the action of a muscle that goes around the inside of the eye and is attached to the lens with some very fine fibres. As that muscle moves forward and backwards, it either releases pressure on the lens and makes it rounder or pulls it and stretches it making it thinner. “It was believed that between the ages of 60 and 70, that muscle
People remain in front of computers for eight hours a day...
designing
everything from cars and planes to kitchen appliances, but biologists had not been aware of it until relatively recently. Professor Pierscionek and her team started to build computer-based models in which material properties could be measured to monitor their shape changing. By observing where the stresses and strains were and what changes occured, the team was able to compare that data with what clinicians observe in the clinic, in a real eye. “It complements the experimental work involved in stretching a lens physically,” adds Professor Pierscionek. Of course, the big challenge for Professor Pierscionek and other
require their first pair of glasses in their 20s and 30s
would get old and stop acting, but researchers in Sweden discovered that the muscle is quite strong until the age of 60 so now we believe that the answer to mimicking the changing shape of the lens does not lie with the muscle – it must be with the lens itself. “We know that as we get older, the lens gets harder, stiffer and, perhaps most importantly, larger. When something is larger it is harder to change. A heavier, bulkier organ will take more force to stretch and as we get older, the muscle does not have that extra force. Another problem for the older lens is that while it gets larger with age, the eyeball does not change at all, so you have a bigger, bulkier lens in an eyeball that has stopped growing and that restricts the space the lens has, making it harder to change shape.”
For Professor Pierscionek, the ultimate goal is to be able to produce an implant lens that is not only optically perfect but one that can change shape for different focal points. As her extensive work over
research teams working on the eye lens, is to develop the “holy grail” of an implant lens that can change shape to focus. “Despite ever increased understanding of the structure and function of the lens, we still do not understand exactly how the lens changes shape,” she explains.
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many years has proved, however, this is optically and mechanically a challenging task. She is confident, though, that by tackling this issue from a number of different angles, answers to the fundamental questions will become clearer. She sums this up neatly: “Once you start working on one project, other questions start to emerge.” It is little wonder, therefore, why Professor Pierscionek continues
her research from this standpoint, seemingly as fascinated by the way different disciplines impact on one topic as she is at reaching her research goals. In fact, it is why she believes she obtained the job at Kingston University in the first place. “I could speak the
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