Quantifiable clinical efficacy of injectable porcine collagen for the treatment of structural dark circles.

[BACKGROUND] Dark circles are one of the most perplexing cosmetic problems for modern people. Nowadays, a new porcine collagen filler has been popular in China and many countries and has high safety.

[AIMS] The purpose of this study is to explore and quantify the efficacy of this collagen filler in treating structured dark circles objectively and systematically.

[METHODS] This is a prospective study. Twenty patients were included and took standard facial photographs at preoperative (Tp), immediately postoperative (T0), 1 week (T1), 2 weeks (T2), 4 weeks (T4), 8 weeks (T8), and 12 weeks (T12). The efficacy was quantified by measuring the depression of the tear trough and infraorbital melanin content. Three dermatologists blinded to the treatment were responsible for completing the subjective evaluations.

[RESULTS] The depression volume, depression-affected area, and depression maximum depth of the tear trough decreased significantly immediately postoperation, and then all values increased slowly with time (P <.05). After 3-month observation, we found that the residual effect of the treatment is 45.08% ± 15.53% (T8) and 17.37% ± 16.79% (T12). The melanin contents at the medial point (A), the middle point (B), and the lateral point (C) all decreased instantly after injection (A: 8.23% ± 5.07%, B: 6.29% ± 5.05%, C: 5.11% ± 5.44% ), which suggested that collagen filler had an instant covering effect for structural dark circles. Patients showed only slight redness and swelling after the treatment.

[CONCLUSION] Collagen filler is a very effective treatment method for structural dark circles. Besides, it may also have a certain therapeutic effect on the other three dark circles types.