The present invention provides an excellent drug delivery system to posterior segments. An injection according to the present invention is a periocular injection which comprises fine particles containing a drug and enables the drug to deliver to the posterior segments. The drug can be efficiently delivered to the posterior segments (such as a retina, a choroid and an optic nerve) while scarcely injuring ophthalmic tissues by administering the fine particles containing the drug periocularlly. Preferred fine particles are made of a synthetic biodegradable polymer, their average particle diameter is 50 nm to 150 mu m, and the drug is dispersed in the fine particles uniformly. Preferred drugs are anti-inflammatories, immunosuppressors, antivirals, anticancer drugs, angiogenesis inhibitors, optic neural protectants, antimicrovials and antifungal agents.
