The present invention relates to a nucleic acid sequence derived from the regulatory region of the human gamma-synuclein gene and having a promoter activity in retinal ganglion cells. The present invention also relates to expression cassettes or vectors comprising said promoter operably linked to a nucleic acid sequence encoding a polypeptide of interest as well as viral particles or host cells comprising said expression cassette or vector. The present invention also relates to the use of said expression cassettes, vectors, viral particles or cells in the treatment of ocular disease, in particular ocular disease associated with retinal ganglion cell or photoreceptor cell degeneration.