Abstract: Provided herein are polymer microparticle-based compositions for the treatment of ocular diseases/disorders (e.g., glaucoma) and other diseases/disorders. Microparticle suspension formulations and solid polymer formulations are described, which provide extended ocular residence time and controlled release of therapeutic agents such as latanoprost, atropine, brimonidine, timolol, brinzolamide, dorzolamide, octyl methoxycinnamate (OMC) and benzophenone-3 (BP3). In specific embodiments, a topical composition comprising drug loaded poly(lactic-co-glycolic acid (PLGA) microparticles or chitosan-coated drug-loaded PLGA microparticles is prepared.