Latanoprost as a new horizon in the medical management of glaucoma

Latanoprost is a new prostaglandin F2 alpha analogue specifically developed for the treatment of glaucoma. Latanoprost is a selective FP receptor agonist, with a primary mode of action of increased uveoscleral outflow of aqueous humor. A dose of 50 micrograms/mL (0.005%) once daily has been found optimal in clinical trials. Latanoprost reduces the nocturnal intraocular pressure in addition to the diurnal, and has been shown to be additive to other glaucoma medication. In long-term phase III clinical trials, latanoprost 0.005% once daily has been proven to be at least as effective as timolol 0.5% twice a day. The main side effect of latanoprost is increased iridial pigmentation, which is relatively frequent in patients with mixed color of the iris. This unique side effect is based on the ability of prostaglandins to stimulate melanin formation in melanocytes. The advantages of latanoprost compared with other glaucoma medication comprise different mode of action, good intraocular pressure-reducing effect, once-daily dosing, and absence of systemic side effects. The long-term consequences of increased iridial pigmentation need to be further studied.