Space research results in test to prevent cataracts

A fibre optic probe developed for the US space programme provides a means to detect the onset of eye cataracts before they become irreversible. The technique is called dynamic light scattering and was initially developed to analyse the growth of protein crystals in a zero gravity space environment. Dr Rafat Ansari, a senior scientist at NASA’s John H. Glenn Research Center brought the technology's possible clinical applications to the attention of researchers at the US National Eye Institute when he learned that his father's cataracts were caused by changes in lens proteins. Several proteins are involved in cataract formation, but one known as alpha-crystallin acts as the eye's own anti-cataract molecule. Humans are born with a fixed amount of alpha-crystallin, so if the supply becomes depleted due to radiation exposure, smoking, diabetes or other causes, a cataract can result. An NEI-NASA clinical trial, reported in the December 2008 Archives of Ophthalmology, looked at 380 eyes of people aged 7 to 86 who had lenses ranging from clear to severe cloudiness from cataract. Researchers used the DLS device to shine a low-power laser light through the lenses. They had previously determined alpha-crystallin's light-scattering ability, which was then used to detect and measure the amount of alpha-crystallin in the lenses. They found that as cloudiness increased, alpha-crystallin in the lenses decreased. Alpha-crystallin amounts also decreased as the participants' ages increased, even when the lenses were still transparent. These age-related, pre-cataract changes would remain undetected by currently available imaging tools. "By the time the eye's lens appears cloudy from a cataract, it is too late to reverse or medically treat this process," said Manuel Datiles, medical officer and lead author of the clinical study. "This technology can detect the earliest damage to lens proteins, triggering an early warning for cataract formation and blindness." Once warned, patients and their doctors may then be able to reduce the risk of cataracts by making changes, such as decreasing sun exposure, giving up smoking, stopping certain medications and controlling diabetes.