The eyes are a focal point of facial expression; not only they convey the full range of human emotion but also have a significant impact on how one is perceived in terms of health and beauty. Efforts to enhance and accentuate the eyes range from simple application of moisturizing creams and colored pigments to medical procedures. Under Eye & Periocular pigmentation is also known as periorbital hyperpigmentation, periorbital melanosis, dark circles, infraorbital darkening, infraorbital discoloration and idiopathic cutaneous hyperchromia of the orbital region.
It is a common condition encountered in dermatology practice and it has a significant psychological impact on our quality of life. Periorbital pigmentation is defined as bilateral, homogeneous hypochromic macules and patches primarily involving the lower eyelids but also sometimes extending towards the upper eyelids, eyebrows, malar regions, temporal regions and lateral nasal root. It is most prevalent in the females in the age group 16-25 years.
Cause of Periorbital pigmentation: It is caused by various overlapping endogenous and exogenous factors. Genetic tendency, sun exposure, mobile, laptop, TV viewing and advanced age are the foremost causes.
Classification of under eye dark circles has been proposed which is based on the clinical pattern of pigmentation and vasculature, and is divided into four types.
1. Pigmented: Characterized by infraorbital brownish.
2. Structural: Appears as shadows formed by anatomic contours which can be easily vanished by stretching the skin
3. Vascular: Appears as infraorbital blue, pink or purple hue with or without edema
4. Mixed type (subtypes-pigmented vascular, pigmented structural, vascular structural and combination of three)
How to diagnose:
1. Diffuse and concentrated melanin deposits (hyperpigmentation)
2. Excessive or superficial subcutaneous vasculature
3. Shadows caused by pseudo herniated orbital fat, skin laxity and tear trough associated with aging
Dark under-eye circles have been notoriously resistant to treatment. Treatment starts with identifying and understanding the primary cause of hyperpigmentation as well as the contributing factors. Optimal results require a multimodality approach to treatment. The treatment course for periocular pigmentation is frequently lengthy, so patients need to be thoroughly counselled. Treatment options include topical depigmenting agents and sunscreens, chemical peels, botox, soft-tissue fillers, laser therapy,surgery, alternative cures and over-the counter cosmetics.
A) Physical Barrier: Sunscreens
Excessive pigmentation is so frequently the major cause for dark circles, the first line of treatment and prevention is the use of a broad spectrum [UVA/ UVB] sunscreen. Patients should be cautious using chemical sunscreens in the delicate eye area application should not extend upto the eyelid margin. Physical sunscreens like zinc oxide and titanium dioxide provide excellent protection from UVA/UVB. Newer silicone formulations works better around the eye.Patients with very sensitive skin can use concealing makeup with a titanium base. Patients should use all-weather UV coated sunglasses that block 99% to 100% of UVA/UVB.
Topical agents Topical phenolic or non phenolic bleaching agents are used in the treatment of hyperpigmentation, particularly hydroquinone and tretinoin. The mechanism of action of most bleaching agents is inhibition of tyrosinase enzyme, which inhibits the conversion of dopa to melanin, hence leading to a reduction of the melanin content of the epidermis.
Hydroquinone is the most prescribed bleaching agent worldwide. It is used in strengths of 2 to 6%.Treatment with hydroquinone can be effective but slow hence treatment should be given for at least three months usually requiring a prescription-strength dose of 4% to achieve good results.Higher concentrations can be compounded (if indicated) but may be irritating,so any increase above 4% should be gradual. Side effects also include allergic contact dermatitis, post inflammatory hyperpigmentation and transient hypochromia. Long-term use can lead to exogenous ochronosis, leukomelanoderma .
2. Tretinoin It is a derivative of Vitamin A acid and is an effective slow bleaching agent that can be safely used in the eye area in an emollient cream base. Tretinoin is a retinoid, a class of drugs that work by dispersing keratinocyte pigment granules, interfering with pigment transfer and accelerating epidermal turnover. Side effects may include erythema and peeling, sometimes it can cause excessive irritation that may exacerbate existing hyperpigmentation hence its use should be monitored.
3. Triple combination The United States Food and Drug Administration (FDA)has approved a modified combination of the containing 4%hydroquinone, 0.05% tretinoin and 0.01% fluocinolone acetonide for use in melasma and various other pigmentary disorders,but since it contains a topical steroid its use in the periorbital area is very minimal.
4. Kojic acid Kojic acid is a naturally occurring hydrophilic fungal derivative produced by Aspergillus and Penicillium species. It acts by inhibiting tyrosinase, and is used in a concentration ranging from 1 to 4%. Long-term use may result in contact dermatitis and erythema.
5. Arbutin Arbutin is an extract of leaves of the bearberry shrub. It is a derivative of hydroquinone and acts by inhibiting tyrosinase activity and melanosome maturation. It is available in 3% concentration. Its effects are dose-dependent, but high concentrations of arbutin can cause exacerbate hyperpigmentation.
6. Azelaic acid It is a naturally occurring non phenolic agent that acts selectively on abnormal melanocytes by inhibiting DNA synthesis and mitochondrial enzymes. In vitro studies show that azelaic acid interferes with DNA synthesis and mitochondrial enzymes in abnormal melanocytes and fibroblasts, thus side effects such as leukoderma and exogenous ochronosis are not associated with its use. It can be used safely for prolonged periods of time. It is considered to be equal to or better than 2% hydroquinone, but may cause pruritus in some patients.
7. Topical antioxidants Vitamin C is an antioxidant and is nowadays widely used for the treatment of hyperpigmentation. As ascorbic acid is unstable in many topical preparations, esterified derivatives, such as L-ascorbic acid6-palmitate and magnesium ascorbyl phosphate are used in compounds. It scavenges the free oxygen radicals,promotes collagen production and conceals color of blood stasis, which could improve appearance of dark circles. Vitamin E may help treat existing hyperpigmentation. Vitamin K is considered as a potential treatment for dark circles because of its presumed effect on the clotting mechanism.
C) Chemical peels
Involve the application of a chemical exfoliating agent to the skin resulting in controlled destruction of the superficial layers of the skin to the required depth, followed by subsequent repair and regeneration. Various peeling agents which are available to reduce peri-orbital melanosis are as below
Glycolic acid: It is keratolytic and stimulates collagen production
Lactic acid: It is keratolytic and has moisturizing effect
Kojic acid: Suppresses the tyrosinase activity
Arginine peels:It increases the elasticity of skin
Ferulic acid: It has antioxidant action