ABSTRACT
This chapter discusses multiphoton imaging of the retina, including the theory of two-photon fluorescence, properties of some of the relevant endogenous fluorophores, and a summary of results from ex vivo and in vivo imaging of retinal structure and function. The strongest source of fluorescence in the frog retina comes from the photoreceptor layer and similar findings have been observed in the primate retina. Nonlinear fluorescence imaging has transformed microscopy in biology because it can take advantage of autofluorescence from naturally occurring, physiologically relevant molecules, has increased penetration depth, reduced photobleaching and intrinsic axial sectioning, and can provide information about the function and health of individual cells. The branch of imaging that studies light emitted by a molecule undergoing electronic transitions is known as luminescence. For optimal two-photon fluorescence imaging, the central wavelength of the imaging beam should to be close to the peak of the excitation spectrum for the sample being targeted.
