j. Cosmet. sci., 51, 127-139 (March/April 2000) A photographic scale for the assessment of human facial wrinkles KAZUE TSUKAHARA, YOSHINORI TAKEMA, HARUHITO KAZAMA, YUKIKO YORIMOTO, TSUTOMU FUJIMURA, SHIGERU MORIWAKI, TAKASHI KITAHARA, MICHIO KAWAI, and GENJI IMOKAWA, Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai, Haga, Tochigi, 321-3497 (K.T., Y.T., T.F., S.M., T.K., G.I.), and Cosmetic Science Laboratories, 2-1-3 Bunka, Sumida-ku, Tokyo, 131-8501 (H.K., Y.Y., M.K.),Japan. Accepted for publication February 15, 2000. Synopsis We report the utility of photographic scales to assess the degree of human facial wrinkles. A five-grade photo scale of wrinkles at eye corners was developed using photos obtained from 411 female participants aged 17 to 83 years. Based on this photo scale, scorings (five grades and nine grades) of all photos were performed by two specialists, and a standard photo for each wrinkle grade was obtained. In addition, in order to evaluate the influence of inter-observer differences in grading criteria, another scoring was performed by five general observers. The agreement between the grade standard and the score given by the general observers was evaluated by calculating the chance-corrected coefficient, i.e., the kappa value. The degree of agreement for the five-grade scale was more consistent than that for the nine-grade scale system, in which the kappa values were 0.499 and 0.396, respectively. When scoring was performed using the five-grade photo scale for the eye corners after 15 participants used a wrinkle-improving agent, a significant reduction of the wrinkle scores was confirmed. Taken together, the present findings indicate that the five-grade wrinkle photo scale is valid and useful to assess the degree of facial wrinkles. INTRODUCTION In recent years, cosmetic agents for the improvement of wrinkles have been actively developed. Photographs have been used for the clinical panel assessment of photodam- aged skin treated with several reagents (1,2). Clinical tests of retinoic acid as a treatment for wrinkles are representative, and the evaluation of its effects is often performed by scoring based on descriptive definitions (3-7). Scoring of photodamage, namely wrin- kling, using a photo scale has been performed, and its statistical validity has been Address correspondence and reprint requests to Genji Imokawa. Tel: 285-68-7467, Fax: 285-68-7305, E-mail: 073733 @kastanet.kao.co.jp 127

128 JOURNAL OF COSMETIC SCIENCE reported by dermatologists (8,9). However, these photo scales of wrinkling are standards for Caucasian people, and it is necessary to develop a photo scale for Japanese, because the principal manifestation of photodamage in Far East Asians, including Japanese, is based on pigmentary change rather than wrinkling (8,14). We therefore evaluated the statistical validity of the evaluation of facial wrinkles using photo scales, and we also examined age-related changes in wrinkles at eight facial sites in Japanese females. In addition, these photo scales were applied to an evaluation of a cosmetic agent for the improvement of wrinkles. MATERIALS AND METHODS SUBJECTS The subjects were 613 healthy Japanese females aged 17-83 years living in the Tokyo metropolitan area. Each subject washed her face using a liquid face-washing agent (Kao Corp., Tokyo) and water. The subjects were photographed in a room with a constant temperature of 20øC and a constant relative humidity of 40-50%. Ten minutes after washing her face, each subject was seated on a chair with her eyes lightly closed, and photos were taken as follows. A photo of the entire face was obtained for the scoring at eight sites on the face, and separate close-up photos of the outer eye corners and the forehead were also obtained. The photographs were taken using a Medical Nikkol camera (Nikon, Tokyo) with a diffused-light electric flash, which has a frame to ensure the standardization of lighting, angle, and distance. All film used (Fujichrome for color transparencies, Fuji Film, Tokyo) originated from the same batch. The first frames of each role of film included a standard gray scale and color charts from the film manu- facturer to facilitate color correction (10). The subjects were photographed in three groups (202 subjects = first group, 164 = second group, and the remaining 247 = third group). SELECTION OF PHOTOGRAPHIC SCALE PHOTOS AND ASSIGNMENT OF STANDARD GRADES Five-grade wrinkle scales for the outer eye corners and forehead. Using a five-point descriptive scale (defined as follows: 1 = none, 2 = mild, 3 = mild/moderate, 4 = moderate, 5 = severe), two specialists separately performed a scoring of wrinkles on photos of the second group (164 subjects) and gave consensus scores. A single photograph with an appropriate score was then chosen to depict each of the five grades. The photo scale for the eye corners is shown in Figure 1. Nine-grade wrinkle scale for the outer eye corners. In the nine-grade evaluation, the five-grade photos selected were given middle scores between grades, resulting in a nine-grade scale. Using the nine-grade photo scale, two specialists separately performed the scoring of wrinkles on photos of the third group of 247 subjects. They discussed the obtained scores until reaching a consensus on the photos to use for each of the nine grades. ASSESSMENT OF THE USEFULNESS OF THE PHOTOGRAPHIC WRINKLE SCALES Comparison of the five-grade and nine-grade scales. Using the five- and nine-grade standard