Tears research open eyes to new possibilities

There’s more to tears than meets the eye, especially now that science has taken a step closer to harnessing their medical potential.Several recent research projects have opened novel avenues exploring the possibilities of using tears to diagnose certain diseases, while others have investigated th as a potential carrier of vital medical information for systic conditions such as diabetes.Vitamins in tears{{quote-A:R-W:450-I:4-Q:“Your body cannot manufacture vitamins, and vitamins reflect available food sources in your body. That’s what makes th good indicators of nutritional health,”-WHO:Dr Maryam Khaksari, Research Specialist at the Chical Advanced Resolution Methods Laboratory (ChARM)}}How far will technology take us along the path towards improving the way eye conditions are diagnosed and determined, so that appropriate and early interventions can be applied? As the old adage goes ‘an ounce of prevention is better than a pound of cure’.Currently, the only methods available to determine nutritional or mineral information are invasive and often expensive blood tests.However, a team of researchers from the Michigan Technological University in the US is working toward a breakthrough in diagnostic testing by using human tears to measure nutritional health and look for early signs of disease.Study lead Dr Maryam Khaksari, a research specialist at the Chical Advanced Resolution Methods Laboratory (ChARM), said the goal was to “seek the viability of establishing measurable vitamin concentrations in tears for nutritional assessments.”“Your body cannot manufacture vitamins, and vitamins reflect available food sources in your body. That’s what makes th good indicators of nutritional health,” Khaksari said while pointing out that nutrients are transferred to the living cells of the cornea.According to Khaksari, it was discovered tears were a viable diagnostic medium after the team found they contained quantities of fat-soluble and water-soluble vitamins comparable to amounts found in much less accessible blood serum.“We hypothesised that nutrients are transferred to the living cells of the cornea through tears and we would like to translate the information we have for blood to tears,” Khaksari said, referencing her earlier research, which found people diagnosed with vitamin deficiencies blinked more often.{{quote-A:L-W:450-Q:“We hypothesised that nutrients are transferred to the living cells of the cornea through tears and we would like to translate the information we have for blood to tears.”}}Khaksari’s research looked at vitamins A, B, and E. The team took blood and tear samples from 15 four-month-old babies and their parents for chromatography and mass spectrometry analysis to scrutinise and compare th.Initial findings revealed that parents have high fat-soluble vitamins in their bodies, while their offspring had more water-soluble vitamins. A correlation was found between the vitamin levels in babies and their parents, especially between vitamins B and E.Additional findings also showed promising results in using tears for vitamin and nutritional information, and the team hopes their research could pave the way for future studies involving the diagnosis of other health conditions with tears.Let the sweat and tears tell youAcross the Pacific, Korean researchers have developed a prototype of a wearable patch that can help monitor blood glucose levels from sweat, taking inspiration from ongoing research on the development of contact lenses that could do the same using tears.The study, published in the journal Science Advances, involved collaboration between three Korean Universities which developed a 4 mm patch that not only monitors blood glucose levels, but also delivers doses of Metformin through micro-needles bedded in the patch when high glucose levels in sweat were detected.The researchers said that although glucose is mostly concentrated in blood serum, early studies have shown that sweat and tears can also provide markers for high body glucose levels. The idea was derived from ongoing research, started two years ago by Google and Novartis, which focused on the development of a contact lens that can test for glucose levels in the body using tears.{{quote-A:R-W:450-I:5-Q:“Just as other biobanks exist for amniotic fluid, blood, and urine, we’ll have a biobank of tears, this would let you do studies in two weeks instead of six months,”-WHO:Dr Noam Sobel, Neurobiologist from Weizmann Institute of Science in Rehovot}}The authors of the study described the device as “a wearable and disposable sweat-based glucose-monitoring device integrated with a feedback transdermal drug delivery module. The syst provides a novel closed-loop solution for the non-invasive sweat-based managent of diabetes mellitus.”Tests of the patches on lab rats are ongoing. Should the preliminary results show promise, the team is likely to seek approval for further investigation and eventually, human clinical trials.Both experiments were aimed at providing a non-invasive, less-expensive, high-compliance approach to diabetes managent.However, the smart contact lens project undertaken by Google and Novartis may have taken a backseat after the pharmaceutical company experienced several technical difficulties when seeking regulatory approval for the device.The issue of the suitability of some potential users to contact lenses and how many different contact lens parameters might be required to fit the bulk of the population has also not been addressed.Before the setbacks, the plan was to develop a smart contact lens bedded with microchips and sensors that monitored glucose levels in tears. The wearable lens would have been paired with a smartphone or tablet app to alert the user to a shift in glucose levels and also recommended the appropriate medication.Proponents of the still developing technology say it is cost-effective and would be more convenient for many people with diabetes, who currently manage their condition by pricking their fingers each time blood samples are required.However, the sweat and tears testing technologies may still be a distant prospect as experts rain unconvinced that there is enough evidence to support glucose testing as a valid substitute for current methods.Former chief scientific officer of Johnson & Johnson LifeScan and chist, Mr John Smith, pointed out while several studies have been conducted on the use of sweat, tears, and saliva, most have proven inconclusive. He believes such experiments are prone to external variables like the environment, humidity, and tperature that can affect the accuracy of results.But, despite this negative assessment, companies such as Apple, EPGLMed, and Canada-based Medella are still pursuing smart contact lens technology for glucose testing and other potential uses.Other researchers have also focused on developing contact lenses that function as a heads-up display to address the rising cases of dry eyes due to extended periods of time staring at computer screens.Holding back the tears{{image2-a:l-w:250}}{{image3-a:l-w:250}}Meanwhile, an Israeli neurobiologist has claimed he has found a way to store human tears effectively in ‘tear banks’ while preserving their properties for use by researchers all over the world.Dr Noam Sobel of the Weizmann Institute of Science in Rehovot believes that he has perfected a process to flash freeze tears to prevent the molecules from degrading. Sobel and his team developed the process using liquid nitrogen to freeze the tear droplets systatically below –80 ° C.Tears are among the least studied substances in the body due to the challenges of collecting a sufficient volume from human subjects and preserving it in its original state. The method created by Sobel and his team, however, was able to preserve the chical composition intact.Sobel is planning to publish his team’s research this year and will then campaign to secure funding to establish a cryogenic facility to serve as a repository for tears.In 2011, he was also responsible for discovering that women's tears contained pheromones that reduce the testosterone levels of men within close proximity. That study was complicated due to the rapid breakdown of chical molecules.{{quote-A:R-W:450-I:6-Q:“We believe we have a unique model to study molecular mechanisms of ocular ZIKV infection, and perhaps to test drugs or new anti-viral molecules to treat this blinding eye disease,”-WHO:Dr Ashok Kumar, Study Lead from The Kresge Eye Institute}}“Just as other biobanks exist for amniotic fluid, blood, and urine, we’ll have a biobank of tears, this would let you do studies in two weeks instead of six months,” Sobel said.Dr Saad Bhamla, a bioengineer at Stanford University welcomed Sobel's tear bank proposal and said that it had “trendous possibilities” for research. Bhamla also revealed he has been using animal tears to study their film-forming properties.Meanwhile, Sobel said he is hoping his repository plan would soon be realised, as it would help answer a lot of lingering questions regarding tears and what the answers might contribute to studies of human otions and conditions.Zika in tearsScientists at Wayne State University’s School of Medicine have discovered the link between the Zika virus (ZIKV) and blindness after it was found to be present in human tears.Dr Ashok Kumar, study lead from The Kresge Eye Institute, said that the virus could replicate in retinal cells and cause severe ocular tissue damage. That makes the Zika virus distinguishable in tears and could soon become a non-invasive process to determine immediately if a person is infected with the virus.{{quote-A:L-W:450-Q:“Indeed, animal and human studies have shown the presence of ZIKV in tears, and there is ongoing research to determine how long, where, and at what concentration the virus can survive in the eye.”}}“We studied the interaction of ZIKV with retinal cells. We observed that ZIKV can replicate and survive in retinal cells and ultimately kill th. Next, we tested whether ZIKV can cause retinal damage using an animal model,” Kumar said.Kumar said that a ZIKV infection in lab mice had caused retinal lesions known as chorioretinal atrophy, which bore many similarities to a Zika-infected human eye.“We believe we have a unique model to study molecular mechanisms of ocular ZIKV infection, and perhaps to test drugs or new anti-viral molecules to treat this blinding eye disease,” Kumar said.“Indeed, animal and human studies have shown the presence of ZIKV in tears, and there is ongoing research to determine how long, where, and at what concentration the virus can survive in the eye,” Kumar added.Tear research has developed substantially but, although there is promise for tears to be used as a testing medium, experts are cautious about using th for diagnostic purposes. The prospect may se distant, however, it is still possible that tears might one day assume their place in medical history.