Preocular sensor system for concurrent monitoring of glucose levels and dry eye syndrome using tear fluids

Abstract

The present study demonstrated a noninvasive preocular sensor system for the concurrent monitoring of diabetes and one of its prevalent complications, dry eye syndrome (DES), using tear fluids. Two distinct sensors, i.e., the glucose and DES sensors, were prepared and encased together in a single housing unit to produce the sensor system, and the tip was designed to be in contact with the eye surface noninvasively to collect and deliver tear fluid to the sensors. The glucose sensor was modified from a commercially available electrochemical sensor to allow for the measurement of glucose concentrations, even in a small amount of collected tear fluid. The DES sensor was equipped with a microchannel spaced with two parallel electrodes to determine the amount of collected tear fluid. In vivo experimental results revealed that with the collected tear fluid of about 0.6-1.0 μl, the sensor system estimated the blood glucose concentrations with acceptable accuracy compared with that of the glucometer in clinical use. The DES condition in animals was diagnosed with high sensitivity (91.7%) and specificity (83.3%).

Advances in Ultrathin Soft Sensors, Integrated Materials, and Manufacturing Technologies for Enhanced Monitoring of Human Physiological Signals

“…[ 117 ] Furthermore, a glucose sensor embedded in the contact lens continuously monitors glucose levels for diabetic diagnostics by accessing tears. [ 118 ]…”

Innovative advancement of contact lenses for noninvasive diagnosis and therapy: A mini review

“…To measure the volume of the collected tear fluid, a noninvasive preocular contact tip would transfer basal tear fluid into the implanted glucose and DES sensors without harming the ocular tissues. The in vivo experiment demonstrated that the two sensors had acceptable accuracy and high sensitivity, and they might provide an alternative, minimally invasive strategy for the chronic management of diabetes and DES 53 . Moreover, Yetisen et al developed a multiplexed scleral lens sensor consisted of fluorescent probes to measure the pH value and electrolyte (Na + , K + , Ca 2+ , Mg 2+ , and Zn 2+ ions) concentrations in the physiological state.…”

“…The in vivo experiment demonstrated that the two sensors had acceptable accuracy and high sensitivity, and they might provide an alternative, minimally invasive strategy for the chronic management of diabetes and DES. 53 Moreover, Yetisen et al developed a multiplexed scleral lens sensor consisted of fluorescent probes to measure the pH value and electrolyte (Na + , K + , Ca 2+ , Mg 2+ , and Zn 2+ ions) concentrations in the physiological state. Different probes were used to detect different ions.…”

Smartphone-Based Electrochemical Systems for Glucose Monitoring in Biofluids: A Review

“…Tears, also known as lachrymal fluid, are from the secretion of the lachrymal gland covering the eye. Han et al proposed a noninvasive preocular sensor system based on the commercially available electrochemical sensor and dry eye syndrome (a prevalent complication of diabetes) sensor for the continuous monitoring of diabetes and dry eye syndrome [ 93 ]. It could estimate the blood glucose levels by the result acquired from the system with acceptable accuracy that was in validation with that of a clinical glucometer.…”