If the leaves are still green, they are contributing to the health of the plant, even in a somewhat limited way. I would suggest leaving them until you see signs of new growth. To be clear, however, you are describing irises that are already planted, yes?

Kay

Yes, they're well established. They seem to do well here with little care, even though its very dry most of the year.

I can't stand to look at them and cut them off.
Renee

I see some new leaves starting in the middle of winter. It's relatively mild here though...it was in the 60s last week, back in the 30s this week.

Should I wait until the frost danger ends before cutting the old tops back?