For creating accessible GUIs with perl there are 2 modules that can be used: Win32::GUI and WxPerl.
Tk-based GUIs are not accessible at all and Gtk2 are not accessible at least under Windows.
Win32::GUI can be used only under Windows, while WxPerl is portable and it offers many more features: more widgets and the possibility to use UTF-8.
The most important WxPerl widgets are very accessible for Jaws and I guess for other screen readers also, because just as Win32::GUI and Java SWT, WxPerl uses the native widgets of the OS.
Java SWING GUIs can be made accessible if using Java Access Bridge, but the accessibility in that case is poor, so SWING is not recommended.
I've made a dictionary using WxPerl that you can download and test and its source code is also available at:
http://www.tranzactiibursiere.ro/maestro
(I developed it while learning WxPerl, so some methods might not be the best ones.)