Is brimonidine better at stabilizing visual field than timolol?

Purpose Alpha‐2 adrenergic agonists are neuroprotective in animal models of focal cerebral ischemia. Brimonidine protects the retinal ganglion cell (RGC) from secondary degeneration following partial crush injury to the rat optic nerve and in an ocular hypertensive rat model. The mechanism for this effect is up‐regulation of brain‐derived neurotrophic factor in RGC and the retina. Brimonidine activates the alpha‐2 adrenoceptor at 2 nM. Topical administration of brimonidine produces pharmacologic drug concentrations in the vitreous (100‐170 nM) in humans that provides a drug delivery route to the RGCs sufficient to bind and activate the alpha‐2 adrenoceptor. In this way, brimonidine could function to maintain the health of the optic nerve independent of its ability to reduce intraocular pressure (IOP) Methods The Low‐pressure Glaucoma Treatment Study (LoGTS) is a triple masked, randomized, multicenter clinical trial of the efficacy of monotherapy with brimonidine versus timolol eye drops to alter the course of low‐pressure (normal‐tension) glaucoma (untreated IOP < 22 mmHg). The primary outcome was visual field progression analyzed using point‐wise linear regression analysis. This methodology required a minimum of four visual fields to obtain and compared the slope of decibel sensitivity of each test location to all previous examinations. Field progression was defined as a negative slope > 1.0 decibel/year with a significance P£0.05 for the same three or more test locations on three consecutive examinations (i.e., over an 8 month interval). Results Previously published articles contains a detailed description of the study methods and baseline patient characteristics and baseline visual field and IOP asymmetry. The current presentation will discuss LoGTS outcomes.Commercial interest