Development and validation of a photonumeric scale for evaluation of infraorbital hollows

Background: A validated scale is needed for objective and reproducible comparisons of infraorbital hollows (i.e., tear troughs) before and after treatment in practice and clinical studies. Objective: To describe the development and validation of the 5-point photonumeric Allergan Infraorbital Hollows Scale. Methods: The scale was developed to include an assessment guide, verbal descriptors, morphed images, and real subject images for each grade. The clinical significance of a 1-point score difference was evaluated in a review of image pairs representing varying differences in severity. Interrater and intrarater reliability was evaluated in a live-subject validation study (N = 297) completed during 2 sessions occurring 3 weeks apart. Results: A score difference of ≥1 point was shown to reflect a clinically significant difference (mean [95% confidence interval] absolute score difference, 0.90 [0.79-1.02] for clinically different image pairs and 0.33 [0.19-0.46] for not clinically different pairs). Intrarater agreement between the 2 validation sessions was substantial (mean weighted kappa = 0.79). Interrater agreement was substantial during the second rating session (0.70, primary end point). Conclusion: The Allergan Infraorbital Hollows Scale is a validated and reliable scale for physician rating severity of hollowing in the infraorbital area.