Ring videocam lights?

I noticed that when I am shooting macro, under +3.5 magnification zoomed in almost all the way, my housing port is often just 50-100 centimeters away from the subject.

Sometimes I am lucky enough to recognize shadowing from the dual HIDs, but more often I see in edit that I wish I had been more particular about light placement.

Often times even with the most careful placement there is shadowing.

Does anyone make a ring light for videocamera dome ports? This would really be a nice light supplemental add-on to existing lighting.