Month: June 2014

It’s a strange phenomenon that some of the most revolutionarily successful people are initially rejected, scorned or unappreciated. Galileo, van Gogh, Darwin, Lovelace, Mendel and Austen were all vastly unpopular in their time, yet now we all take their scientific and creative contributions for granted. Sir Harold Ridley, the inventor of the intraocular lens, is another example of these late-sung heroes. His work saves the eyesight of millions of people across the world every year, but at first his idea of placing a plastic lens onto the surface of the eye was thought by peers to be impossible, laughable and even dangerous.

The eyeball acts like a camera: light from the outside travels through the pupil and the lens to focus on the back of the eye, where the light is translated into images by light-sensitive cells that are located there. Due to age, trauma, toxic chemicals or certain diseases such as rubella or diabetes, the proteins that make up the lens denature and become opaque which prevents light from entering the eye and causes cataracts. People with cataracts suffer from very poor vision or blindness (see the image comparison); over half the world’s blindness (around 20 million people) is caused by age-related cataracts alone.

Over the course of history, several gory approaches to treating cataracts have been trialled. Somewhere between 2000-600BC, a procedure called ‘couching’ was used. This procedure involved using a sharp instrument, or just blunt pressure, to detach the cataract-riddled lens from where it normally resides into the back of the eye. Not surprisingly, this procedure was usually massively unsuccessful: patients usually suffered pain (as this was before a lot of modern anaesthetics were available), inflammation, infection and even blindness as a result. Even if the procedure and aftercare went smoothly, the patient was still left with inadequate eyesight. Unfortunately, couching is still performed in some developing countries where access to healthcare is often restricted.

As general surgical practice improved over the centuries, better tools and instruments were developed that allowed the opaque lens to be either removed, or broken up into small, more easily absorbable pieces. More often than not, patients were still left with poor eyesight and had to wear cumbersome, thick glasses to compensate for the missing lens.

Dr Harold Ridley, a recently trained medical doctor who specialised in ophthalmology, worked in the south of England during the Second World War. In August 1940, Flight Lieutenant Gordon ‘Mouse’ Cleaver forgot to put on his flight goggles before going out in his plane for what was to be Adlertag (Eagle Day) – the first day of Luftwaffe’s mission to eliminate the Royal Air Force from the sky. On returning to base, a bullet went through the side of Cleaver’s cockpit and shattered the Perspex window, a small fragment of which entered his eye. Cleaver had many operations on his face to treat the damage, but Dr Harold Ridley’s operation was to change medical history.

When Ridley removed the Perspex from Cleaver’s eye, he observed that there was no inflammation: the body hadn’t recognised the material as ‘foreign’ and so hadn’t initiated an immune response against it (as it usually does against materials like wood or metal). Ridley started thinking: if you could take the Perspex out of eye and there was no inflammation, then there would surely be no biological reason why you couldn’t put it back in.

With this in mind, Ridley developed the first intraocular lens (IOL) – a small disc made from Perspex – and in 1949 placed it into the eye of his patient after first removing her cataract. With further modifications to improve the IOL’s power (that is, the ability of the lens to bend light, as glasses do), some of his first patients even attained 20/20 vision. Initially, Ridley sought to keep his patients’ implants a secret from the academic community until he could confirm from follow-up checks that there were no adverse effects, but a patient accidentally let slip the secret. So, in 1951 Ridley published his results and took two of his patients to be inspected by the Oxford Ophthalmological Congress. His work was rejected by other eye experts and deemed heretic. As a result, Ridley became a professional pariah and sank into depression.

But not everyone was so sceptical about the IOL. Foreign eye doctors saw the promise of the invention and in 1974  – 25 years after the first IOL implant – a Club was started with the aim of discussing the use of IOLs in cataract surgery. Robert Young, a famous American actor, underwent the procedure and sang its praises to the press. Only years after he retired in 1971 was Harold Ridley officially recognised by the ophthalmic societies and institutions. In 2000 he was knighted by Queen Elizabeth, but he passed away in 2001.

The long-unappreciated work of Harold Ridley is now recognised as not just an invaluable contribution to ophthalmic medicine, but also one of the first ever feats of bioengineering. Applying a scientific strategy such as using materials that are foreign to the body to fix a medical problem was previously unheard of, yet today we benefit from IOLs, dental implants and pacemakers to name just a few. Increasingly, bioengineering takes advantage of 3D printing and other advancing technologies and materials in the production of tissue grafts and implants that, like IOLs, will make such a huge difference to peoples’ lives.

Post by Natasha Bray

For as long as carnivals and funfairs have been around, there have been people who try to guess your age; a trick that often goes hand-in-hand with horror at the response. With our ageing population, which is most likely due to advances in medicines, treatments and our understanding of diseases, age is quite topical.

A recent study has shown that observing  the anatomy of your brain may be able to uncover your true age. A set of biological markers has been shown to accurately predict the age of a young person’s brain. So, if you have ever told a white lie about your age at the cinema to get a child’s ticket, or if you ever tried to trick shop owners into thinking you were 18 so that you could be served alcohol or cigarettes then this could soon be a thing of the past!

Previous studies have tried to observe aspects of brain structure and function with the aim of identifying whether there are common patterns and timings during the development of our brains. Although many studies have been unsuccessful in trying to show this, a study carried out by Timothy Brown at the University of California combined a range of parameters regarding the structure of the brain in order to assess its age. Using 885 subjects aged between 3 and 20 years, individuals were selected from a diverse range of races, educational backgrounds and economic statuses.

Children can develop – in terms of mental capability and maturity – unpredictably, but what is not known is the extent to which these differences are based on physical features of their brain, and or are due to psychology or environment.

Magnetic resonance imaging (MRI) was performed on each of the subjects to look at the internal structure of brains, of which 231 features were studied, including certain structures, the connectivity between different regions, and thickness or volume of different areas of the brain.

Large variations in many of the measurements were observed that corresponded to the ages of the subjects. By combining the data from each of the measurements using a complex mathematical equation, an accurate ‘snap-shot’ of how the brain appears at each age during development was formed.  Although there were slight differences during development between brains of a similar age, the equation was able to correctly predict the age of a child to within a year, with an accuracy of 92%.

These findings indicate the presence of a developmental clock within our brain that produces a precisely timed development of brain structures throughout childhood.

Although these findings are incredibly interesting, aside from giving us insight into how our brains work you may be wondering what the relevance of these findings are. Whether we would be able to use the same technique to reliably determine the age of an adult by looking at the structure of their brain is another question. To be able to identify the true age of an individual has many advantages, but one of the most important clinical applications of this would be in observing whether a child’s brain is developing at a rate that is comparable to others of a similar age. It would also be useful in observing brain structures in individuals with autism, and other developmentally related disorders.

There are also non-clinical applications for this technique, such as cases where border staff need to be able to accurately determine the age of an individual without documents to be able to make a decision on whether to grant asylum. In the Olympic Games in Beijing in 2008, controversy arose when officials were unable to decide whether some of the competing athletes had entered the games illegally by lying about their age in order to compete.

To further this work, the study should address whether the anatomy of the brain is able to reliably predict age in subjects that have reached adulthood. If biomarkers are able to accurately predict our age even after development, then this could lead to rapid advances in the development of medicines for age and development-related illnesses.

Study: Neuroanatomical assessment of biological maturity – Timothy Brown et al. – Current Biology, September 2012.

Post by  Sam Lawrence