Devices that deliver monochromatic infrared energy (MIRE) are approved by the Food and Drug Administration for certain uses, but it seems they are no better than placebo treatments in reducing the foot numbness experienced by people who have nerve damage related to diabetes.

“Clinicians should be aware that MIRE may not be an effective modality for improvement of sensory impairments in patients with diabetic neuropathy,” warn Judy K. Clifft, a physical therapist at the University of Tennessee Health Science Center in Memphis, and colleagues, writing in the medical journal Diabetes Care.

The U.S. FDA approved MIRE devices in the mid-1990s to increase circulation and reduce pain and have been used in patients with wounds and soft-tissue trauma. Several case reports and uncontrolled studies have suggested that MIRE may improve lower-extremity sensory neuropathy.

The Memphis group tested the value of MIRE in an 8-week study involving 39 adults with diabetic peripheral neuropathy, who were randomly treated with actual or sham MIRE therapy applied on three days per week for four weeks.

According to the team, 30 minutes of real MIRE was no more effective than sham MIRE in improving sensation on the sole of the foot. “There were no significant differences between active and placebo groups at any measurement,” Clifft and colleagues report.

It’s worth noting, according to the team, that foot sensation increased for both the active MIRE and placebo MIRE groups. Therefore, if the study had been done without a placebo control, “the active MIRE treatment would have appeared to be therapeutically effective.”

SOURCE: Diabetes Care, December 2005.