Prostaglandin postscript: a personal reflection.

The long and arduous process that led to the development of ocular hypotensive prostaglandin derivatives over the past three decades has been reviewed several times. In this "postscript" to the second Survey of Ophthalmology supplement devoted to the ocular hypotensive effects of prostaglandin derivatives, only two aspects of this new approach to the medical management of glaucoma are discussed: 1) The implication of the observed prostaglandin-induced increase in iridial pigmentation with respect to the understanding of the role of prostaglandins and of iridial melanocytes in the protection against the damaging effects of light, and in the maintenance of normal intraocular microenvironment; and 2) The rationale behind the use of a combined formulation of a prostaglandin derivative and a beta-blocker for the protection against increased intraocular pressure. The need to consider not only target pressure, but also target mechanisms, in the selection of medical therapy regimen for any given glaucoma patient is emphasized.