  We used ultraviolet (200 nm) images of the local spiral galaxies M33, M51,
M81, M100, M101 to compute morphological parameters of galactic disks at this
wavelength : half-light radius $r_{hl}$, surface brightness distributions,
asymmetries ($A$) and concentrations ($C_A$). The visibility and the evolution
of the morphological parameters are studied as a function of the redshift. The
main results are : local spiral galaxies would be hardly observed and
classified if projected at high redshifts (z $\ge$ 1) unless a strong
luminosity evolution is assumed. Consequently, the non-detection of large
galactic disks cannot be used without caution as a constraint on the evolution
of galatic disks. Spiral galaxies observed in ultraviolet appear more irregular
since the contribution from the young stellar population becomes predominent.
When these galaxies are put in a (log $A$ vs. log $C_A$) diagram, they move to
the irregul ar sector defined at visible wavelengths. Moreover, the log $A$
parameter is degenerate and cannot be used for an efficient classification of
morphological ultraviolet types. The analysis of high redshift galaxies cannot
be carried out in a reliable way so far and a multi-wavelength approach is
required if one does not want to misinterpret the data.
