<p>Identification Of Three Key Factors Contributing To The Aetiology Of Dark Circles By Clinical And Instrumental Assessments Of The Infraorbital Region</p>

Abstract

Background: The aetiology of infraorbital dark circles is complex and multi-factorial. The aim of this research was to measure and characterize dark circles and to determine the physiological changes associated with the occurrence of this aesthetically unpleasing issue. Materials and methods: Clinical, photographic and instrumental assessments were performed on Caucasian skin to determine the most appropriate methodologies to measure dark circles, comparing different zones of the infraorbital region in subjects with and without dark circles. Exploratory studies were also carried out on African and Far East Asian skin, as well as on tracking the natural variation of dark circles over seven days in Caucasian subjects. Results: Under-eye dark circles in Caucasian subjects are characterized by significantly darker coloured skin and higher colour deviations between the dark circle region and surrounding areas of skin. Multispectral image analysis produced a higher melanin index in subjects with dark circles, suggesting hyperpigmentation in the affected area, in addition to a higher haemoglobin index. The higher haemoglobin index, combined with preliminary assessments of the vascular network by videocapillaroscopy, suggests there may be more dilated, thicker or increased numbers of capillaries in subjects with dark circles. Ultrasound analysis showed a significant difference in skin thickness between the two groups of subjects linking the appearance of dark circles to thinner skin under the eye. Many of these trends were also observed in African and Far East Asian skin. The results also showed intra-individual, intra-day and inter-day variability of dark circle intensity in subjects with Caucasian skin. Conclusion: Three key physiological factors associated with the occurrence of infraorbital dark circles are hyperpigmentation, a tendency for more dilated, thicker or increased number of capillaries and thinner skin in the under-eye area. The combination of these three factors provides a robust indication of the presence of infraorbital dark circles.

A validated photonumeric scale for infraorbital dark circles and its application in evaluating the efficacy of a cosmetic treatment product in a split‐face randomized clinical trial

“…Although there was also a slight change in grade in the untreated eyes at 8 weeks, the net difference between treated and untreated was 0.59, and crucially, there was a continuous decrease in the grade over the treatment period. A slight change is the untreated eye is not entirely unexpected, as we have previously observed temporal fluctuations in the appearance of dark circles [3]. Our data have shown that changes in grade of greater than 0.5 correspond to ΔE values of between 1 and 2, which is within the range perceivable to the human eye and therefore the mean treatment change observed in the clinical trial is consumer relevant.…”

“…The aetiology of infraorbital dark circles is complex; causal factors include excessive pigmentation because of melanin deposition, vasodilation and venous stasis, thinner skin of the eyelids and structural features of the orbital area [3–5]. This can be compounded by the ageing process, which results in skin sagging and altered subcutaneous fat distribution [1–7]. In addition, numerous intrinsic and extrinsic factors have been associated with their occurrence [8, 9].…”

“…The key principle in the evaluation of dark circles is the assessment of the relative darkness of the under‐eye colour compared to the surrounding facial skin. This can be performed objectively through instrumental measurements or by image analysis [3, 4, 12, 13, 14]. Indeed, these techniques can remove subjectivity and are helpful for showing whether a treatment has induced significant changes.…”

“…This photonumeric scale concept has been applied to other photoageing parameters, such as crow’s feet wrinkles [18], where grading follows the general guidelines of a modified Griffiths scale. Although dark circles have been evaluated by clinicians’ visual assessments and some proprietary grading scales are available [3, 4, 7, 19, 20], to the best of our knowledge there is currently no published, validated consensus dark circles clinical grading scale, meaning it is not possible to achieve consistency nor directly compare results among laboratories and evaluators across testing centres.…”

Clinical Observation of 48 Cases of Black Eye Circle Treated with Modified Yu Rong San Gel Eye Mask

“…Most of them are distributed symmetrically in all age groups. At present, most of the drugs for the treatment of dark circles are expensive and ineffective [3][4][5][6][7] . Yurong powder comes from Qianjin Yaofang, which can remove blackness and brighten skin color.…”