Digital Image Speckle Correlation (DISC) Analysis for Targeted Cosmetic Treatment and Effect Quantification of Botulinum Toxin Type A

Purpose:

Administration of Botulinum Toxin (BT) for the cosmetic treatment of facial wrinkles has traditionally been determined using anatomic landmarks, with effect monitored by subjective assessment tools and questionnaires.¹ Our study applied DISC analysis, a novel, non-invasive technique that measures facial muscle animation, to select injection locations as well as quantify degree of paralysis and time to recovery. DISC analyzes skin deformation to measure the magnitude and direction of facial muscle contraction.² Vector profiles indicate points of maximal tension and thus ideal injection sites. Using pre-treatment and follow-up DISC data, we characterized patients' facial muscle recruitment and compared it with subjective cosmetic effect and satisfaction.

Methods:

9 female Caucasian patients aged 30-65 were photographed prior to BT treatment in a uniform position using a head stabilizer, with the face at rest and engaging the muscle group of interest (glabellar and forehead). DISC analysis identified vector convergence points, representing ideal injection locations (Figure 1). Each patient received a total 50 units of BT among sites in the upper face determined using DISC. Photos were taken at each follow-up (3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 8 weeks, 12 weeks). DISC analysis quantified changes in muscle recruitment, as measured by percent decrease in contraction strength from baseline. DISC data was corroborated with patient satisfaction using the Facial Line Outcomes 11-item survey (FLO-11).

Results:

Average injection number was 16±2 among subjects, and paralysis was seen in all patients by day 3. Maximum paralysis (-0.638±0.11) was detected with DISC on day 28, which also correlated with the maximum reported benefit as measured by FLO-11 (0.427± 0.05) (Figure 2).  DISC demonstrated recovery at day 56 (-0.464±0.15) with a concurrent drop-off in mean FLO-11 scores.

Conclusions:

DISC determines ideal injection locations prior to cosmetic treatment with BT toxin by identifying the skin's points of maximal stress. DISC quantifies subtle changes in contraction strength, corresponding to cosmetic effect duration. DISC is a reliable, objective metric for aesthetic outcomes, enabling clinicians to provide an accurate prediction of treatment effect and duration to their patients.