Detection of magnetic particles in live DBA/2J mouse eyes using magnetomotive optical coherence tomography.

OBJECTIVES: To demonstrate in vivo molecular imaging of the eye using spectral-domain magnetomotive optical coherence tomography (MMOCT). METHODS: A custom-built, high-speed, and high-resolution MMOCT was developed for imaging magnetic particle-coupled molecules in living mouse eyes by applying an external dynamic magnetic field gradient during optical coherence tomography (OCT) scanning. The magnetomotive signals were tested in vitro by scanning magnetic beads embedded within an agarose gel (1.5%) and in vivo in the anterior segment of a mouse eye. RESULTS: Cross-sectional OCT images of the gel and the anterior segment of the eye were acquired by regular OCT structural scanning. Magnetomotive optical coherence tomography signals were successfully captured in the agarose gel with embedded magnetic beads. The signals were captured in the anterior segment of the mouse eyes after injecting the beads. The signal was overlaid successfully onto the structural OCT image. CONCLUSIONS: We demonstrated the ability to detect particles injected into the anterior chamber of the mouse eye using MMOCT. This suggests that MMOCT is effective for future live detection of molecular (protein) targets in various ocular diseases in mouse models.