A randomized, split-face, double-blind, comparative study of the safety and efficacy of small- and large-particle hyaluronic acid fillers for the treatment of nasolabial folds.

BACKGROUND

Injections of hyaluronic acid (HA) for tissue augmentation are one of the most common aesthetic treatments performed worldwide. However, few studies have compared the safety and efficacy of small- and large-particle HA (SP-HA; LP-HA).

AIM

To assess and compare the safety and efficacy of SP-HA and LP-HA for the correction of nasolabial folds (NLFs).

METHODS

A prospective, split-face, triple-blind study design was used. Ten female subjects were recruited. Patients underwent treatment at baseline, an optional touch up at Week 2, and a follow-up visit at Week 4. At weeks 2 and 4, a blinded reviewer assessed the patients using the Global Aesthetic Improvement Scale (GAIS) and Wrinkle Severity Rating Scale (WSRS); and subjects completed the Patient Satisfaction Questionnaire (PSQ). At all visits, 3-dimensional imagery and ultrasonography of patients' NLFs were captured. Adverse events (AEs) were evaluated by the Investigator and recorded by subjects in diaries.

RESULTS

The GAIS response rate, defined as ≥ "improved" from baseline, was between 90 (2 weeks) and 100% (1 month) for SP-HA and was 100% for LP-HA, at both visits. Paired-samples t tests revealed significant differences in the change in WSRS scores between groups, at both visits (P < .01). Differences in the clinical effect and lifting capacity of both products were observed in 3-dimensional imagery and ultrasonography. Treatment volumes varied, with 61.32% more SP-HA being required than LP-HA for achieving a ≥ one-grade WSRS improvement. There were no severe AEs throughout the trial, nor AEs related to the investigational device.

CONCLUSIONS

LP-HA demonstrates better efficacy for correcting bony resorption in the nasal pyriform region.