Enucleate the eyes of a euthanized mouse, marking the temporal side for orientation purposes. Remove the anterior chamber. Then remove the lens and vitreous and place eye cups in paraformaldehyde for 30 minutes.
Wash eye cups with PBS for 30 minutes. Replacing the solution three times. Then, wash with 0.5%Triton X-100 for 30 minutes.
Incubate eye cups in the blocking buffer for two hours at room temperature. After immunostaining, isolate the retinas from the eye cups using a microscope. Divide the retinas into four leaves and flat mount them with the retinal ganglion cell layer facing up.
Ensure the mark on the temporal side remains attached for orientation. Cover the retinas with mounting medium. Place cover slips.
And seal the slides using nail polish. Turn on the confocal microscope and under Locate mode, find the area of interest using the eye piece. Switch to Acquisition mode and set up tiles to cover the entire retina, along with Z-Stack slices for all layers of information.
Image at least 25 tiles across the whole retina to achieve a total volume. Project the Z-Stack slices to generate two-dimensional on-face confocal microscopy images. The composite vis-OCT fibergram is compared with the corresponding confocal image of flat mounted retina immunostained with TuJ1 for RGC axons.
Blood vessels exhibit distinguishable branching structures which can be matched with the ICAM-2 labeled blood vessels on the confocal image. Side-by-side comparison between ex vivo confocal microscopy and in vivo vis-OCT revealed identical RGC axon bundle networks and surrounding retinal vasculature.
