perlTk able to process Unicode starting from Tk804.02x versions, for perl 5.8.x

But even when that Unicode-awared version was not yet released, it was possible to do Unicore-awared GUI using installed Tcl/Tk, and with Tcl::Tk module as a bridge to communicate them, for perl 5.6.x and 5.8.x

You can see sample at http://www.vkonovalov.ru/vtcl-usage/Using_vtcl_for_creating_Tcl-Tk_GUI_for_Perl.html

update fixed typo in link