Accuracy of Areal Measurement in the Periocular Region Using Stereophotogrammetry.

PURPOSE:The purpose of this study was to evaluate the accuracy of stereophotogrammetric area measurements in the periocular region and analyze the differences between the 2 genders and 2 races. MATERIALS AND METHODS:A prospective study was performed on healthy young volunteers. The sample was composed of 20 Caucasians and 20 Chinese volunteers. Five objects of different sizes (0.16 cm2, 0.36 cm2, 0.64 cm2, 1.44 cm2, and 2.56 cm2) were placed at 7 periocular locations. Caliper and the VECTRA M3 system were used for direct and 3D stereophotogrammetric analysis. Accuracy and differences in 2 different genders and 2 races were analyzed. The predictor variable was the mean absolute deviation between the 2 measurement methods. The nonparametric Wilcoxon signed-rank test or paired t-test was used to test the statistical differences between the 2 measurement methods. A P value < .05 was considered statistically significant. RESULTS:The mean difference between the 2 measurements of all objects was less than 0.02 cm2, nonparametric Wilcoxon signed-rank test or paired t-test showed no statistically significant (P > .05, respectively) differences between the 2 measurement methods, except for object 1 and object 5 (endocanthion). Chinese and female volunteers tend to have lower accuracy than Caucasians and male volunteers. CONCLUSIONS:Three-dimensional stereophotogrammetry is highly accurate for area measurements in the periocular region.