Back to 2016 Annual Meeting

Background:
Historically, physicians have relied upon their judgement when determining the site of injection of Botulinum toxin (BT) in the treatment of facial rhytids, as well as how many units to utilize. These decisions are often made after subjectively evaluating the muscle mass and degree of wrinkle formation. Unfortunately, this method is inherently subjective and operator dependent. Digital Image Speckle Correlation (DISC) is a technology that tracks pore movement from rest to maximal exertion, thus allowing for the determination of the optimal sites of injection. Furthermore, DISC provides the ability to track the degree of paralysis following BT injection. In this prospective cross-over trial, we compare the efficacy of using DISC compared to physician assessment in choosing BT injection sites.
Methods:
10 female patients aged 32-59 (mean 46.8) were enrolled in our study. Subjects were randomized to two arms, one receiving injections based on DISC analysis and the other receiving injections based on the 2004 "Consensus Recommendations on the Use of Botulinum toxin Type A in Facial Aesthetics". Subjects were blinded as to which method was being used. All patients received 20u of BT in the glabellar region. Follow up photographs and DISC analysis were completed weekly for the first month, then monthly up to six months post-injection. The Facial Lines Outcome 11-item survey (FLO-11) survey was also administered at each follow-up. After 6 months, subjects were crossed over and were re-injected utilizing the other method. Follow-up for the second injection was the same as the first. Statistical comparison was completed via matched sample T-test.
Results:
Five subjects have completed the entire crossover study. Three subject were injected utilizing DISC for the first arm of the crossover. On average, the DISC analysis provided 4.8 injection sites, while
the practitioner chose 5 injections sites. When matched by week, the mean FLO-11 score was better in patients receiving DISC directed injections (p=0.126). The degree of paralysis was also greater when injecting based on the DISC recommended sites (p=0.002). Furthermore, DISC directed injection maintained paralysis for a longer period of time and patients were less likely to return to their baseline movement within the six month follow up period. In comparison, patients injected via the standard method had muscle function return to baseline on average at week 16 post-injection.
Conclusions:
The decision to inject a patient with BT is often made based upon the judgement and preferences of the practitioner and patient. Due to a lack of standardized practice, there is often much variability in the site of injection and number of units injected between different practitioners. Currently, there exists no evidence-based tool that adequately addresses this issue. This study demonstrates the benefits of using DISC in determining where the practitioner should inject BT. Based on our results, using DISC to determine where to inject may lead to a greater degree of paralysis, as well as a longer duration of effect. DISC analysis allows practitioners the ability to better treat facial rhytids by eliminating subjective decisions about dose and site of injection.