Fig. 3: In vivo correlation analysis between tear glucose (TG) and blood glucose (BG) with normal and diabetic rabbits.

a Schematic illustration of the simultaneous measurement of TG and BG during IVGTT in a rabbit model. b Timeline of BG, and TG measurement after oral administration of glucose in normal rabbits. c, Representative data of monitoring TG and BG in normal rabbits after oral administration of glucose. d Pearson’s correlation coefficient between TG and BG as a function of lag time. e Timeline of continuous measurement of TG and BG after glucose intravenous (IV) injection for normal rabbits. f Timeline of continuous measurement of TG and BG after IV injection of glucose and insulin for diabetic rabbits. g Representative real-time data of TG and BG in a normal rabbit after IV injection of glucose. (i), Real-time monitoring of TG (black dots), BG (red dots), and corrected TG data (blue dots) of a normal rabbit. (ii), Comparison between the average of TG and BG in four normal rabbits before and after the injection of glucose, and the error bars indicate mean ± standard error of the mean. h Representative real-time data of TG and BG in a diabetic rabbit after IV injection of glucose and insulin. i Real-time monitoring of TG (black dots), BG (red dots), and corrected TG data (blue dots) of a diabetic rabbit. (ii), Comparison between the average of TG and BG in four diabetic rabbits before and after injection of glucose and insulin, and the error bars indicate mean ± standard error of the mean. i Lag time identification through the Pearson’s correlation coefficient in rabbit models. j Comprehensive Pearson’s correlation analysis of 4 normal rabbits and FOUR diabetic rabbits. k Comprehensive Parkes error grid analysis of four normal rabbits and FOUR diabetic rabbits.