Figure 2. Autofluorescence intensity in the human trabecular meshwork. Extracellular matrix (ECM)-derived autofluorescence (AF) intensity (mean gray value) was determined for tissues from 4 human donors (A, B, C, and D). Each column represents mean pixel intensity for a donor human trabecular meshwork (TM) excited at a particular two-photon (2P) wavelength. Mean intensity of four donor tissues for each excitation wavelength is shown as an adjacent black column. Error bars=standard deviation.