Abstract: Photoactivatable dendrimers and hydrogels formed therefrom include dendrimers to which polymer chains (e.g. polyethylene glycol, PEG) have been conjugated; and reactive photoactivatable groups attached to terminal functional groups of the polymer chains (e.g. hydroxyls of PEG). Exposure to a suitable wavelength of light activates the photoactivatable groups, which then crosslink with one another, thereby forming a hydrogel. The hydrogel may also include one or more agents of interest; or, in some embodiments, nanoparticles containing one or more agents of interest may be dispersed in the hydrogel. These formulations are well-suited for sustained or prolonged delivery of active agents, e.g. for the treatment of glaucoma by the sustained delivery of anti-glaucoma agents directly to the eye.