  Considering, as a limit case, an approximately flat pion distribution
amplitude, which is determined from the hardest, in momentum space, solution of
the Bethe-Salpeter equation for the pion wave function, we compute the pion
transition form factor $F_{\pi\gamma\gamma^{*}}(Q^{2})$ and the pion form
factor $F_{\pi}(Q^2)$, taking into account the LO as well as NLO form of the
hard coefficient function entering the leading-twist factorization formula. We
also compute the exclusive photoproduction of pions pairs at high energies,
$\gamma \gamma \to \pi^{+}\pi^{-}$, where perturbative QCD can be used to
compute the hard scattering matrix elements. We verify that the existent data
for exclusive pion production can be reasonably described as a function of such
flat distribution amplitude.
