The present invention relates, generally, to improved methods of delivering a biologically active agent, in particular a therapeutic or prophylactic nucleic acid, to the ocular sphere of a subject comprising administering said agent to the ciliary body tissue(s) or cells and/or to the extra-ocular muscle tissue or cells. More particularly, the invention relates to devices, their uses, notably in gene therapy, and to methods for treating pathologies of the ocular sphere by specific ciliary body tissue(s) or cells and/or extra-ocular muscle or cells administration of a therapeutic product and transfer thereof into the ocular tissue to be treated. This invention also relates to pharmaceutical compositions comprising the product in a form suitable for ciliary body tissue(s) or cells and/or extra-ocular muscle or cells administration, their preparation and uses.