  The Coulomb corrections to the helicity amplitudes of high-energy photon
splitting are examined. The consideration is based on the amplitudes obtained
exactly in the parameter Z\alpha within the quasiclassical approach valid for
small angles between all photon momenta. We consider the case when the
transverse momenta of both final photons are much larger than the electron
mass. It is shown that at Z\alpha \sim 1 the Coulomb corrections essentially
change the result for the cross section as compared to the Born approximation.
The effect of screening is also taken into account.
