Effect of Timolol and UF-021 (a Prostaglandin-Related Compound) on Pulsatile Ocular Blood Flow in Normal Volunteers

Abstract

The effects of topically applied timolol (a nonselective beta-blocker) and UF-021 (a prostaglandin-related compound) on pulsatile ocular blood flow (POBF) were investigated in 9 healthy volunteers. One drop of either UF-021 or timolol was instilled in one randomly selected eye and the fellow eye received physiologic saline. Before and 90 min after drop instillation, we measured intraocular pressure (IOP), POBF, heart rate (HR) and blood pressure (BP). After a washout interval of at least 1 week, the other drug was instilled in the previously treated eye. IOP, POBF, HR, and PB were measured following the same protocol. After timolol administration, IOP and POBF decreased significantly in the treated eye (26%, p = 0.01, and 13%, p = 0.02, respectively) and in the fellow eye (11%, p = 0.01, and 11%, p = 0.03, respectively). HR also decreased (10%, p = 0.03), but BP did not change significantly. After UF-021 administration, no significant changes were found in IOP, POBF, HR, or BP. Our results suggest that in normal subjects timolol decreases POBF in both the treated and the untreated eyes, whereas UF-021 has no action on either IOP or POBF.

The short‐term effect of latanoprost on intraocular pressure and pulsatile ocular blood flow

“…Although we cannot with certainty rule out the possibility that the IOP lowering effect of latanoprost may account for these increases, we can point to data indicating that other mechanisms may be responsible. Previous studies have shown that a significant reduction in IOP does not necessarily result in increases in OPA and POBF (Bosem et al 1992;James 1994;Morsman et al 1995;Kitaya et al 1997).…”

“…Kitaya et al reported that Unoprostone had no effect on either IOP or POBF in healthy volunteers before and 90 minutes after instillation (Kitaya et al. 1997).…”

“…Ocular blood flow is influenced by many factors including the use of various antiglaucomatous drugs. Some antiglau-comatous drugs have been shown to reduce OBF (Bosem et al 1992;Carenini et al 1994;Morsman et al 1995;Kitaya et al 1997;Schmetterer et al 1997) and may impose a risk of decreasing blood supply to the vulnerable structures of the optic nerve head. The use of antiglaucomatous drugs that reduce OBF should therefore be avoided.…”

Effects of Timolol and Dorzolamide on Retrobulbar Hemodynamics in Patients with Newly Diagnosed Primary Open-Angle Glaucoma

“…Timolol’s influence on ocular hemodynamics remains unclear as varying results have been reported. With the OBF system, POAG patients treated for 1 month with timolol 0.5% did not have any significant pulsatile blood flow alteration; however, Kitaya et al [23]reported a significant pulsatile OBF reduction in the treated and fellow eyes of a group of healthy volunteers 90 min after timolol administration. Conversely, Grunwald [24, 25]reported an increase in retinal blood flow measured with laser Doppler velocimetry in controls and ocular hypertensives after topical administration of timolol.…”

Pulsatile ocular blood flow: Changes associated with scleral buckling procedures

“…In addition, we have previously shown that there is a significant negative correlation between POBF and axial length. [7][8][9] The purpose of this retrospective study was to determine whether the decreased choroidal circulation detected shortly after SB is maintained for longer periods.…”