Prospective comparative clinical study: Efficacy evaluation of collagen combined with hyaluronic acid injections for tear trough deformity

Background: Tear trough filling is a popular facial rejuvenation procedure, and hyaluronic acid is typically used as the filler of choice. However, Tyndall's phenomenon, a common complication following hyaluronic acid injection, can occur, leading to skin discoloration of the lower eyelid. Aims: This single-center, prospective, comparative clinical study aimed to evaluate the efficacy of collagen and hyaluronic acid injections in treating tear trough deformity. Methods: Sixty patients were enrolled between June 2022 and January 2023. Patients were randomly allocated into three groups: Group A received hyaluronic acid, Group B received hyaluronic acid combined with collagen, and Group C received collagen alone. Baseline characteristics, including age, sex, and tear trough deformity grade were considered before therapy. Changes in tear trough deformity scores, Global Aesthetic Improvement Scores, and the presence of the Tyndall effect were analyzed at 1 and 3 months postinjection to determine differences among the three groups. Results: Baseline profiles of the three groups were similar. In the first month postinjection, there was no difference in the Global Aesthetic Improvement Scores and tear trough deformity between the three groups. However, in the third-month postinjection, there was a significant difference in scores between patients in Group C and those in Groups A or B. The Tyndall effect manifested in three patients in Group A, which was significantly different from that in Groups B and C. Conclusion: The combined use of hyaluronic acid with collagen in injectable fillers corrected tear trough deformities and reduced the occurrence of the Tyndall phenomenon, which can be problematic with hyaluronic acid alone. Additionally, this combination may help overcome the disadvantage of a shorter retention period when using collagen alone.