Traditionally, chronic wound infection is diagnosed and treated based on visual inspection under white light (WL) and microbiological sampling. These methods are suboptimal because they are subjective and do not accurately represent the overall bacterial load in the wound. To address this, we have developed a novel handheld fluorescence imaging device that enables non-contact, real-time, high-resolution visualization of key pathogenic bacteria through their endogenous autofluorescence (FL).
To demonstrate the feasibility of autofluorescence imaging in guiding wound treatment and quantitatively assessing treatment response.
A pilot-phase, non-randomized trial of 12 patients with diagnosed chronic and/or acute wounds was conducted in Toronto, Canada. In this group, wound area was tracked over 6 months, comprising of three sequential 2-month periods, to compare treatment delivered without (control) and with FL guidance (guided). FL imaging was used to locally guide debridement and target antibiotic application.
During the first standard treatment period, there was a slight decrease in average wound area over time, but this was statistically insignificant (slope -0.005cm2/day). However, when FL imaging was used to guide treatment, a larger decrease in average wound area was observed (slope -0.046 cm2/day), which was significantly different (p=0.015) compared to the first control period. In the second control period, a slight increase in average wound area (slope +0.007 cm2/day) was observed, which was significantly different from the rate of change seen in the FL guided period (p=0.010). The significance of the slope for each 2-month period was p=0.579, p<0.001 and p=0.501, respectively.
This data suggests our device can be used to provide FL image guidance for wound treatments to accelerate wound closure and for monitoring treatment response by quantitatively tracking wound size and changes in bacterial bioburden and distribution in wounds.