and the not so benign malignant that may arise in nevus of Ota and blue nevi. Without intervention, it worsens with advancing age and may be associated with other health disorders.22 A medical workup is needed before embarking on aesthetic treatment. Table 1 illustrates a recommended work up of POH and focuses on the patient medical history and physical examination as a roadmap to successful treatment (Table 1).
Anatomic Considerations for POH
POH has distinct anatomical features, which affect treatment decisions. In classic POH, when examining the lower eyelid component, the uppermost or proximal boundary is the tarsal plate of the lower eyelid. The most distal boundary is at the tear trough deformity. The tear trough is not exclusively the product of aging. Young people including children have a tear trough. It is the deepening of this groove that leads to indentation and becomes a visual deformity that affects facial appearance. To devise the optimal correction for the tear trough component of POH, understanding the anatomy of this area is critical. The nasojugal fold was defined initially by Duke-Elder, Wybar, and Loeb in 1961.23 It was then in 1969 renamed the tear trough deformity by Flowers as the observation that tears will track along this groove.23 The tear trough is the medial one-third of a periorbital sulcus. The sulcus starts at the lower eyelid inner canthus involving the thin loose eyelid skin and runs downward to the thicker skin of the cheek. The indentation that defines the tear trough deformity is at the junction of thin eyelid skin above and the thicker nasal and medial cheek skin below, marking the line along which the fascia is anchored to the periosteum.12,21,22 Concave surfaces replacing convex surfaces is the hallmark of facial aging. Our facial aesthetic efforts are focused on restoring convex facial surfaces. In our skin of color patients especially, this indentation, groove, or tear trough may be the only area of concavity visible in the face and thus may be the earliest sign of aging.7 The concave contour of the periorbital soft tissues results in a hollow area that creates a tired appearance. The shadow or dark halo created by this groove is commonly perceived as a dark circle or ring under the eye. Laxity of the lid-cheek junction with age accompanied with the herniation periorbital fat pads, involutional descent of the midface, and osseous and fat atrophy with aging may further contribute to the loss of soft tissue support and descent of the cheek that deepens the tear trough.20
Association With Aging
In addition to the anatomic changes described above for POH, photodamage has been demonstrated in cases of POH. Cumulative UVR damage results in a cascade of oxidative stress. Cytokine release with activation of matrix metalloproteinases results in collagen degradation, solar elastosis, and clinically rhytides. Loss of luminosity and progressive pigmentation results from UVR-induced activation of AP1 Complex and NF KB.24 Without intervention, POH worsens for females and males with advancing age.
There is not a lot of literature on the histology of POH. Watanabe et al looked at biopsies from periorbital skin in 12 Japanese patients diagnosed with POH. Melanin pigment in was seen in upper dermal macrophages they found S100 and Fontana-Masson positive dermal melanosis.25 Graziosi et al reported a histological evaluation of 28 cases with CIHOR. Twenty-eight adult patients who were diagnosed with CIHOR were elected for the study. Biopsy specimens were taken from the darkened skin of the eyelid. The control was uninvolved retro auricular skin. Their results were as follows: Hemosiderin was absent in all cases. The increase in melanin content in the papillary dermis was slight in mild clinical cases and moderate in both the moderate and severe clinical cases of CIHOR. Mild dilation of blood vessels were observed in the papillary dermis at the different clinical levels of CIHOR severity, while in the reticular dermis, blood vessels showed moderate dilation and few melanophages were found. The author concluded that an increase in melanin content was the most marked histological change in specimens of darkened skin. Dilation of dermal blood vessels may contribute to the severity of CIHOR.26 These histologic findings are very important in our discussion of the POH with our patients. The fact that most of the melanin was dermal, as has been supported by Watanbe and Graziosi, clinically correlates with the difficulty in treating this disorder and the observed resistance of POH to respond to topical treatments.
There are many disorders that may mimic or be associated with POH. Because this may be a special opportunity to diagnose an underlying health issue prior to formulating a treatment plan, it is recommended rule out the following disorders (Table 2).
Periorbital hyperpigmentation is often refractory to treatment. Aesthetic treatment modalities, both monotherapy and in combination, have been used for POH. They include microdermabrasion, chemical peels, lasers, radiofrequency, injectable fillers, surgery, fat transfer, hydroquinone (HQ) and non-HQ skin bleaching, and brightening agents, retinoids, ascorbic acid, botanicals, and other cosmeceuticals (Table 3).29