Prostaglandins are derived from fatty acids and are found in almost every human tissue. Structural differences account for their different biological activities, which is determined by the type of receptor to which the prostaglandin binds.
Prostaglandins for the treatment of glaucoma have been used since the late 1990’s and include latanoprost, travoprost, bimatoprost and tafluprost. It’s use for lash growth was discovered after many glaucoma patients were growing longer, thicker and darker lashes. This lead to the birth of Latisse, indicated for the treatment of hypotrichosis and FDA approved in December 2008. Latisse is 0.03% bimatoprost and is thought to work on the anagen phase of hair growth by increasing the percentage of hairs in anagen and increasing the duration of anagen.
Potential side effects occurred in the clinical trials in less than 4 percent of patients, most of which are thought to be reversible, such as redness, itching, periocular hyperpigmentation, and hair growth in unwanted areas. What is not thought to be reversible is iris hyperpigmentation, which can occur as early as three months after initiation.
Prostaglandin associated periorbitopathy is another side effect that is a popular topic of discussion lately. It was first reported by Peplinski and Smith in 2004 and has been written about since then many times. A study by Park et al. showed a statistically significant increase in adipocyte density in treated eyes indicating adipocyte atrophy. Concerns in relation to the periorbitopathy include upper lid ptosis, deepening of the superior sulcus, involution of dermatochalasis, enophthalmos, inferior scleral show, and prominence of lid vessels.
Beneficial considerations for periorbital prostaglandins are mainly targeted toward lower lid fat prolapse and clinical trials are under way. As well, researchers (Draman et al.) are looking into prostaglandin use for the treatment of Graves’ orbitopathy, as early studies show a significantly reduced proliferation and adipogenesis of human orbital fibroblasts.