We propose a novel parallel plate waveguide (PPW) metasurface. The PPW is periodically loaded with glidesymmetrically arranged dielectric-filled cavities in both conductors. By filling the cavities with dielectric, the equivalent refractive index increases. To facilitate the manufacturing using conventional methods, the walls of the cavities are implemented with metallic vias and the proposed structure is used to design a Luneburg lens. Compared to previous works on holey metasurfaces, the designed lens is cheaper and more resilient to manufacturing errors.