Na and Ca diffusion was induced in glasses by intense microbeams of swift protons. By contrast with previous studies using macrobeams (semi-infinite geometry), the geometry of the interaction is cylindrical which offers new directions for diffusion. Furthermore, we explored the influence of high current densities. The main results show that Na migrates towards the surface in the irradiated zone, and is then spread around this region. The Ca signal variation is not interpreted as a diffusion process, but only as a reflection of the change in matrix density. The Na migration is shown to be driven by an electric field created in the irradiated cylindrical zone.