Compositions, kits, and methods for reducing intraocular pressure (IOP) in a subject (e.g., human) include at least one naturally occurring or synthesized version or analog thereof of a lipid (e.g., a phosphoserine, a phosphocholine, a psychosine or other glycolipid) that is endogenous to non-glaucomatous aqueous humor in a subject and that lowers IOP in the subject, in a therapeutically effective amount for promoting aqueous outflow through TM in at least one eye of the subject and reducing IOP in the subject. The compositions can be used for, e.g., treating glaucomas, including, for example, primary open angle glaucoma (POAG) and normal tension glaucoma (NTG).
