BACKGROUND: Recent studies on postoperative measurements for upper blepharoplasty utilized static photographs, which fail to accurately reflect the postsurgical dynamic naturalness of the eyelids. OBJECTIVES: In this study we aimed to analyze dynamic naturalness after double-eyelid blepharoplasty with a simple smartphone method involving slow-motion videos. METHODS: In this prospective observational study we enrolled patients who underwent double-eyelid blepharoplasty with the flexible suspension technique (FST) and rigid fixation technique (RFT), and individuals with congenital double eyelids. Demographic information was collected, and ultra-slow-motion videos of the eye-opening processes were recorded with a smartphone. Four keyframes were selected from each video, from which several parameters were measured. A third party evaluated the degree of naturalness of the photographs and eye-opening videos. RESULTS: Sixty females (20 per group) were enrolled. The fold-emerging delay (FED) score showed a linear correlation with the mean third-party dynamic naturalness rating (DNR) (R2 = 0.71, P <
.0001). The puffy score showed a linear correlation with the mean third-party static naturalness rating (SNR) (R2 = 0.53, P <
.0001). For the congenital, FST, and RFT groups, respectively, the FED scores were 62.9 ± 18.9, 52.2 ± 17.7, and 26.3 ± 18.3 (all P <
.05)
the puffy scores were 49.8 ± 11.9, 55.9 ± 11.0, and 62.6 ± 12.4 (congenital vs FST, P = .055
others P <
.05)
the mean third-party DNRs were 3.21 ± 0.67, 2.47 ± 0.62, and 1.78 ± 0.74 (all P <
.0001)
and the mean third-party SNRs were 3.01 ± 0.78, 2.61 ± 0.55, and 2.14 ± 0.69 (all P <
.05). CONCLUSIONS: The 2 new indices obtained from the analysis of smartphone-captured ultra-slow-motion videos are good indicators of the dynamic naturalness of double eyelids created with upper blepharoplasty.