Glucose sensing in the anterior chamber of the human eye model using supercontinuum source based dual wavelength low coherence interferometry

Abstract

Supercontinuum source based dual wavelength low coherence interferometry (DWLCI) technique is proposed to measure glucose in the aqueous humor of the eye. Studies were conducted in the second overtone region, first overtone region and combination band to determine the favourable wavelength region for glucose measurement. Bandpass filters at centre wavelengths 1300 nm, 1580 nm, 2100 nm and 2250 nm were used to filter out appropriate bands of interest for the study from the broad wavelength range of 900–2800 nm. In the studies, human eye model was used to simulate the anterior chamber of the eye containing artificial aqueous humor with varying physiological concentrations of glucose ranging from 0 to 250 mg/dl. Studies based on spectral shift measurements and relative reflectivity were conducted. Enhancement in the resolution of glucose was obtained in the combination band at 2100 nm compared to the first overtone region at 1580 nm, due to the increase in the absorption of glucose in the combination band. Glucose resolution of ≈10.3 mg/dl was estimated in the first overtone region. Whereas, an enhancement in the resolution of glucose of ≈2.4 mg/dl was attained in the combination band. Keywords: Glucose sensing, Low coherence interferometry, Differential absorption, Supercontinuum source, Combination band, Aqueous humor