High-resolution multimodal visible light optical coherence tomography and scanning laser ophthalmoscopy for in vivo neuronal and vascular retinal imaging in mice.

Microglial cells play a crucial role in retinal vascular and brain diseases through complex interactions with blood vessels and neurons. To image retinal structures, vasculature, and microglia, we developed a multimodal system integrating visible light optical coherence tomography (vis-OCT) and scanning laser ophthalmoscopy (SLO). Both subsystems achieve micron-scale resolutions and operate within the diffraction limit across a 34-degree field of view: theoretically, the OCT system offers an axial resolution of 2.12 μm and a transverse resolution of 8.78 μm, while the SLO system provides a transverse resolution of 7.1 μm. We validated the system performance using transgenic mice with fluorescent protein-labeled microglia, revealing detailed retinal microstructures, microvasculature, and individual microglia with distinguishable branches, confirmed by ex vivo microscopy.