Light bending in the galactic halo by Rindler-Ishak method

After the work of Rindler and Ishak, it is now well established that the bending of light is influenced by the cosmological constant {\Lambda} appearing in the Schwarzschild-de Sitter spacetime. We show that their method, when applied to the galactic halo gravity parametrized by a constant {\gamma}, yields exactly the same {\gamma}- correction to Schwarzschild bending as obtained by standard methods. Different cases are analyzed, which include some corrections to the special cases considered in the original paper by Rindler and Ishak.