Eye scanner developed by Boston University School of Medicine can detect molecular aging in humans. The new technique detects age-related damage to the eyes and may one day play a role in doctors' routine clinical practice.
Everyone ages, but two people of the same age can be in very different states of he alth. In other words, chronological age and biological age are different. But while chronological age is very easy to measure, biological age is more difficult to estimate. Currently, there is no universally accepted measure of biological aging in humans.
In a new study appearing in the Journal of Gerontology, researchers at Boston University School of Medicine describe a tool that may fill this gap. Researchers have developed a new eye scanner that detects the molecular signs of aging and is completely non-invasive, reports medicalnewstoday.com.
It's all in the eyes
Expensive tools to assess aging limit their application and scientific understanding of this process, explains Dr. Lee E. Goldstein, lead author of the paper. “The lack of clinical tools and metrics to quantify how everyone ages at the molecular level represents a major obstacle to understanding aging and optimizing he alth across the lifespan.”
To address this, Dr. Goldstein and a team of researchers from various institutions, including Boston Children's Hospital and Harvard Medical School, looked for clues to the process in the eye.
Eyes are a good measure of aging because they contain cells that are generated in the fetus and are not replaced. This means that the cells a person is born with remain in them for life. These cells are called primary and appear in the lens of the eye, which focuses light on the back of the eye.
By the way, these cells contain the highest concentration of protein in the human body. Importantly, these proteins do not regenerate, so they accumulate damage in he alth over a lifetime. This damage can provide a molecular readout of the aging process. As Dr. Goldstein says, the lenses provide a “permanent record” of a person's life history.
Decoding the molecular records
To decode this molecular information, the researchers used a technique called quasi-elastic light scattering, or QLS, which used lasers to measure the size of the particles. The technique works because the molecular damage that occurs in lenses over time causes changes in the shape of the proteins that stick together. This collection of altered proteins alters light scattering in a way that QLS can reveal. The team first tested the technique in isolated lenses that were incubated in a test tube for varying lengths of time - up to almost a year - to mimic the way these proteins age people aged 12, 30 and 53.
They found that over time the molecular footprint of the proteins changed as they expected and that this was detected by the QLS scanner. They then tested the scanner in an experiment with 34 people between the ages of 5 and 61. The scanner was able to detect the same age-related changes they had seen in the lab.
Precision Medicine
Although further testing is needed, the authors say these results support the use of the scanner to track molecular aging in humans. They say the tool could work similarly with other clinical biomarkers, such as brain imaging for Alzheimer's disease and blood tests for diabetes. Physicians could eventually use the tool in routine clinical practice to provide an individualized measure of molecular aging and perhaps even help identify interventions to extend the he althy span of a person's life.
