A Single-Center Pilot Study to Classify of Signs of Dorsal Hand Aging Using Three Grading Scales
Along with the face, neck and chest, hands are to visible signs of aging. As in other parts of the body, human aging on the dorsal hand is characterized by thinning of the dermis and reduced collagen synthesis. Loss of dermal collagen results in skin laxity and the appearance of crepiness and wrinkles. Additionally, photo-damage, mostly due to ultraviolet radiation, causes degradation of elastic fibers and the appearance of dark spots. Finally, soft tissue atrophy and resultant volume loss expose underlying structures, such as veins, tendons, and joints, and bony prominences. Hand rejuvenation procedures, including sclerotherapy, fillers, microneedling, laser resurfacing, and intense pulsed light therapy, are commonly used by plastic surgeons to combat the processes that cause aging of dorsal hand skin. Objective tools to evaluate the efficacy of these cosmetic treatments are therefore needed.
To date, the Merz Hand Grading Scale is the only hand grading scale that has been validated for the assessment of dorsal hand aging. This scale, however, is limited, in that it only evaluates volume loss. As other factors also contribute to the appearance of aged hands, more scales that take these additional components into account must be created.
The objective of this study was to develop three validated scales for the assessment of signs of dorsal hand aging. The goal was to determine whether photographic classification systems of wrinkles and spots, both intensity and density, can be used consistently to objectively characterize the dorsal hand.
Methods/Technique:
Three numerical scales were created in this study. The Dorsal Hand Wrinkle Scale ranges from Grade 0 (no wrinkles) to Grade 4 (deep wrinkles with defined edges), while the Dorsal Hand Pigmentation Density and Intensity Grading Scales are four-point scales ranging from Grade 0 (no dark spots) to Grade 3 (severe dark spots). One dorsal hand was photographed and edited in Adobe Photoshop (Adobe Systems, San Jose, CA) to create a visual representation of all three scales. Additionally, sample subject photos were chosen for each grade as further reference.
Up to 50 healthy volunteer subjects with Fitzpatrick skin types I-IV were recruited for this study. Exclusionary criteria included any unique features on the dorsal hands that could result in subject identification and any excess hair or skin conditions that might interfere with classification. Images of the left and right dorsal hand were taken using a Nikon D7100 in the Department of Plastic Surgery professional photography studio. Using up to 25 randomized photos, five reviewers were trained on the three scales. Additionally, evaluators were asked to provide a score for the validated Merz Hand Grading Scale. After a discussion of grading decisions, the reviewers viewed the 75 remaining photographs and assigned a grade to each photograph for the three investigational scales and the Merz Hand Grading Scale. The rate of interobserver agreement was calculated for the three scales under investigation and the Merz Hand Grading Scale.
Results/Complications:
Although no demographic data information was collected from subjects, a wide variety of dorsal hands were photographed, ranging from no visible signs of aging, to severe wrinkling, laxity, and dyschromia. It was ensured that multiple photographs were obtained for every score on all of the grading scales.
The three scales under investigation were reliably and consistently used to characterize wrinkles and dark spots on the dorsal hand. After training the five reviewers on these three scales, interobserver variability was low. Furthermore, the interrater agreement for each of the three scales was similar to the results of the Merz Hand Grading Scale assessment.
Conclusion:
The results of this study demonstrate the reliability and validity of three new scales that characterize the appearance of wrinkles and dark spots on the dorsal hand. After analyzing the results of all three scales, interobserver variability was low and of a similar degree to that seen with the Merz Hand Grading Scale assessment. These scales provide a simple tool to objectively measure the changes associated with aesthetic treatments specifically targeting the dorsal hand, and clinical evaluations of the aging hand no longer have to be limited to volume loss.