CASE REPORT
A 47-year-old Caucasian female presented to our hair transplant clinic for evaluation of sparse eyebrows. She reported very thin eyebrow hair on her left eyebrow for many years. The process had been gradual but was cosmetically significant, and she was interested in initiating treatment.
Upon examination, the patient was found to have sparse hair on her left lateral eyebrow (Figure 1a). Her right eyebrow and left medial eyebrow were clinically normal. Both surgical options (follicular unit transplantation)1,2 and medical treatment (topical bimatoprost) were discussed at length with the patient. The decision to initiate topical bimatoprost therapy was made, and the patient was instructed to apply the solution once daily for four months to her left eyebrow only.
At a follow-up visit four months later, the patient reported significant thickening of her left lateral eyebrow. She also reported that she had been using the solution approximately every other day. Physical examination revealed increase left eyebrow density, hair length, darker color, slight skin pigmentation, and eyelash treatment (Figure 1b). The patient was instructed to maintain use of topical bimatoprost every other day.
DISCUSSION
Hypotrichosis is characterized by less than normal amounts of hair. The issues that hypotrichosis of the eyelashes and eyebrows create are multifaceted. Eyebrows and eyelashes provide a defense against foreign bodies for the eye, and furthermore, full eyebrows and eyelashes can make the face look more cosmetically attractive.3 Causes of hypotrichosis can vary from aging, chemotherapy, genetic, or other medical treatment and unknown causes.4 Previous studies have established that Latisse (bimatoprost 0.03% solution) increases eyelash length, thickness, and darkness in patients with hypotrichosis of the eyelashes.3
Topical bimatoprost was FDA-approved for eyelash hypotrichosis in December 2008. In previous studies bimatoprost, a synthetic prostamide analog used topically, has been shown to reduce intraocular pressure and helps control the progression of glaucoma.5 The mechanism of bimatoprost is complex. Bimatoprost works by increasing the overall percentage of eyelash follicles in the anagen cycle at any one time. Bimatoprost also stimulates melanogenesis, which results in darker pigmentation of eyelashes. In addition, bimatoprost likely increases the size of both the dermal papilla and hair bulb.6
The method by which bimatoprost works is through interactions between prostaglandins and prostamides with prostanoid receptors. These receptors are known to be present in the dermal papilla and in the outer root sheath of the hair follicle. It has been shown that the receptors are involved in the development and regrowth of hair follicles.7 This interaction stimulates hypertrichosis by promoting resting follicles in the telogen phase
