placed for that, especially in the fields of engineering and the sciences. As with many of our academics, I can bring a real interdisciplinarity to my work, which, I believe, makes it much more useful in the real world.” Professor Pierscionek’s research is in vision science and her
predominant focus is on the human lens, in particular the causes of cataracts and optical image quality. Such is the nature of her approach, however, that the work is also focusing on improving the design of implant lenses, which are used to replace the biological lens when a cataract develops. This is done by understanding exactly how the natural lens is built, how it functions and every aspect of
its makeup from a
biological, biochemical, engineering, mathematical and mechanical viewpoint. She
is also examining
ways in which the home environment can be improved for the visually impaired, as well as novel ideas to help prevent premature sight deterioration. It is a wide portfolio. In the modern research landscape, this
this n
interdisciplinarity is encouraged by funding bodies that understand the advantage of approaching a problem from a number of different angles. This was not always the case, however. Professor Pierscionek’s original work on the human lens and the causes of cataracts came at a time when the use of animal models was becoming more popular. She reasoned that work on certain animal eyes had little relevance to optics of the human eye, instead choosing to study every aspect of the lens itself, from the structural proteins that compose it to the optical properties it possesses. “I was using laser ray tracing, and that allowed us to see how light
travelled through the lens,” she recounts. “This also required some complex mathematics to calculate the refractive index, so my PhD ended up being a hybrid of biochemistry and mathematics. It was doing this that helped me to realise that a balance of knowledge is essential to understanding a problem in its entirety. A given hypothesis can make sense in one area but not in another. That is why when studying the human lens, you need to understand the physics, the optics, the biochemistry, and even the biomechanics and engineering, to appreciate the lens’ ability to refract, change shape and provide the eye with sufficient image quality.” After finishing her PhD at the University of Melbourne in
Australia, Professor Pierscionek was the youngest scientist to be granted a very prestigious National Health and Medical Research (NHMRC) fellowship, allowing her to set up an independent research programme looking into the refractive index of the human lens. The refractive index determines how light moves through a substance, and is created by the density of that substance. In materials such as water or glass this is easily calculated, as the refractive index is uniform throughout. However, the refractive index of the human lens changes with every few cell layers, giving it a gradient of refractive index that is much harder to ascertain mathematically. “I developed a method that uses optical fibre probes to measure the refractive index at different points throughout the lens,” explains Professor Pierscionek. “I was able to use these measurements to gain a better understanding of how light travels through it.” The graduated nature of refractive index in the human lens has been central to Professor Pierscionek’s work since that early
www.projectsmagazine.eu.com e t One of the current projects that Professor Pierscionek leads, which s
is funded by Fight for Sight and has a co-investigator at Cardiff University, is looking at improving implant lens design, using her early experimental work as a basis. As she explains, there is no cure for cataracts so lens replacement is currently the only treatment. This is of vital importance as people are living longer and cataracts are associated with the ageing process. Part of the experimental work for this project is conducted in Japan at the most advanced synchrotron facility in the world, the SPring-8 synchrotron. Professor Pierscionek and her team travel to Japan to undertake novel experiments on the refractive index and protein density in human eye lenses. Together with Japanese colleagues they are the
study. “Because of the size and structure of the eye,” she explains, “it would need a high refractive index to do the bending needed to get the light to the retina and if it were a uniform index lens, it would be very solid and rigid. By having a refractive index gradient,” she continues, “the bending is incremental and the human lens achieves
the
same amount of power for a lower density, allowing the lens to be more pliable. This density gradient is also better
for optical quality. but
With a refractive index gradient, the light rays focus in one place, avoiding distortions. “The eye lens is very sophisticated in that sense, this
complexity the whole point;
is
created by the proteins and is
the
proteins’ density and distribution create the refractive index gradient and no one has really understood how that all works – and if we did, we could
produce better implant lenses.”
Refractive index measurements used to simulate lens contours (A) compared with clinical images and from live eyes (B, C). These results have been used to predict the structure of the live lens, which can help with the design of new intraocular implants. These images come from a scientific paper that was published in Experimental Eye Research in July 2014
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