  We compute the gluon distribution in deep inelastic scattering at small x by
solving numerically the angular ordering evolution equation. The leading order
contribution, obtained by neglecting angular ordering, satisfies the BFKL
equation. Our aim is the analysis of the subleading corrections. Although not
complete - the exact next-to-leading contribution is not yet available - these
corrections are important since they come from the physical property of
coherence of QCD radiation. In particular we discuss the subleading correction
to the BFKL characteristic function and the gluon distribution's dependence on
the maximum available angle. Conformal invariance of the BFKL equation is lost,
however this is not enough to bring the small-x gluon distribution into the
perturbative regime: although large momentum regions are enhanced by angular
ordering, the small momentum regions are not fully suppressed. As a
consequence, the gluon anomalous dimension is finite and tends to the BFKL
value $\gamma=1/2$ for $\alpha_S \to 0$. The main physical differences with
respect to the BFKL case are that angular ordering leads to 1) a larger gluon
anomalous dimension, 2) less singular behaviour for $x \to 0$ and 3) reduced
diffusion in transverse momentum.
