The objective of this program is to utilize more of the information available when angiography is performed. Fluorescence techniques have been developed for in-vitro determination of stress or degradation of single and aggregated of cells and of membranes. These techniques will be adapted to in-vivo use in animal models and a correlation made between fluorescence changes and retinal integrity. The fluorescence polarizability, excitation and fluorescence spectra, fluorescence decay times and fluorescence intensity will be measured after intravenous injection of a series of dyes that have already been shown usable for angiography. Both normal and intentionally damaged retinas of monkeys and rabbits will be studied.