Longitudinal three-dimensional visualisation of autoimmune diabetes by functional optical coherence imaging

Area of Science:

• Biomedical Imaging
• Diabetes Research
• Islet Biology

Background:

• Quantitative imaging of pancreatic islets is crucial for understanding type 1 diabetes pathogenesis.
• Current methods may lack the speed or specificity for dynamic monitoring of islet structure and function.

Purpose of the Study:

• To introduce functional optical coherence imaging (FOCI) for rapid, label-free monitoring of beta cell destruction and islet vascularization.
• To enable quantitative, longitudinal assessment of islet alterations in diabetes models.

Main Methods:

• FOCI was used to image mouse and human islets transplanted into the anterior chamber of the eye (ACE).
• The technique leverages intrinsic refractive index variations for fast tomographic acquisition and phase sensitivity for label-free vascular imaging.

Main Results:

• FOCI enabled longitudinal quantification of insulitis, beta cell volume, and vascularization in 3D.
• High specificity for functional beta cell volume was achieved due to backscattering from insulin-zinc nanocrystals.
• A strong correlation was observed between insulitis progression and islet vascular network density in a mouse model.

Conclusions:

• FOCI is a novel imaging technique for studying diabetes-induced islet alterations.
• It allows label-free detection of beta cell volume, infiltration, and vascularization, valuable for ACE-transplanted human islets.
• This method aids in understanding islet transplant rejection and in vivo drug efficacy monitoring.