556-P: Noninvasive Measurements of AGE Products in the Crystalline Lens of the Eye Can Distinguish Subjects with Prediabetes and Type 2 Diabetes and Correlated with Severity of Neuropathy

Abstract

The accumulation of advanced glycation end products (AGEs) in the body contributes to pathogenesis of many diseases including complications of diabetes including retinopathy and neuropathy. Proteins in the lens of the eye do not turnover and therefore give an indication of the average glucose levels over a very long period of time. AGEs have a unique measurable fluorescence, however non-invasive measurement of AGEs was not available until recently with introducing a new scanning confocal biomicroscope. The main aim of the present study was to investigate if measurement of lens Auto fluorescence (FL) can distinguish subjects with impaired Glucose Tolerance (IGT) and type 2 diabetes (T2DM) from Healthy control subjects and to investigate the relationship between levels of FL. ratio, and corneal nerves morphology. 20 T2DM, 20 IGT and 20 Healthy aged matched control subjects underwent comprehensive medical and neurological assessments including corneal confocal microscopy and measurement of Crystalline Lens Autofluorescence by using a confocal bio microscope. There was a significant difference at the level of fluorescence ratios in Control subjects, IGT patient and T2DM patients. There was a significant correlation between FL. Ratios and level of HbA1C, and CNFL.

The results of this study showed the Lens fluorescence is significantly greater in patients with IGT and T2DM. The level of AGEs products was correlated with HbA1C and alterations in corneal nerves morphology. However, the relationship with HbA1c was rather poor since HbA1c cannot completely reflect long-term glycation process. Lens autofluorescence could be a robust marker of long-term diabetes control predicting future complication risks. This supports the feasibility of lens autofluorescence to screen subjects for undiagnosed type 2 diabetes. However, confirmation of such hypothesis will need larger and long-term clinical studies.