Abstract: In vivo imaging may be used to assess a condition (e.g., a state of glaucoma or a state of ocular hypertension) of an eye of a living animal. A dye may be intravenously injected into the living animal. The dye may bind to amyloid in the nervous system of the animal. Images may be taken of a retina, an optic nerve head, an optic nerve, the lateral geniculate nucleus, and/or the visual cortex. Images may be taken using methods such as fluorescent angiography, magnetic resonance imaging, computed tomography, positron emission tomography, and/or single photon emission computed tomography. The condition of the eye and/or retinal ganglion cells in the eye may be assessed from one or more of the images. The condition of the eye may be assessed based on the presence of amyloid in one or more of the images.