Human Tears: Glucose Instabilities

Abstract

Using a photometric method, a comparative analysis based on 717 human tear samples was made between systematically collected non-reflex, open eye tears and tears associated with prolonged eye closure (sleep), as well as for certain reflex provoking conditions (mild mechanical irritation, irritating vapours and osmotic imbalance). Although the closed eye tear glucose mean for the 8 young adults studied was found to be less that their open eye mean (5.01 versus 7.00 mg%), those 2 values were not found to be significantly different. However, statistical comparisons made between non-reflex open eye tears and the mechanical, irritating vapour and osmotic responses were found to be different at the P less than 0.05 level of significance, a higher mean concentration being found for the mechanical and osmotic conditions, and a lower mean concentration of the vapour induced condition.

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

“…However, to be more accurate, the user instruction regarding to the tear collection time may need to be properly provided. In many previous studies, to obtain tear fluids sufficient for measurements, the eye surface was stimulated to intentionally induce reflex tear generation [ 42 – 44 ], or tear fluid was collected for a longer duration, i.e., minutes [ 19 ], which would cause measurement inaccuracies and eye irritation.…”