I'm self-employed and my spouse is self-employed. How can we reduce SE tax?

We each earn about $110,000.00. Each file own Schedule C. We're in the same profession, optometry, but it is impossible to combine our two practices because her lease arrangement prohibits any association with a competitor. She rents a space in an optical chain, I have a stand alone business. If we were one business, I think we'd pay much less of the social security component of the self employment tax.