Abstract
Purpose: :
Recently it has been reported that impairment of optic nerve head (ONH) blood flow affects the progression of glaucomatous optic neuropathy. Some studies have indicated that prostaglandins increase ocular blood flow in animals and human. The purpose of this study is to compare the effect of tafluprost, travoprost and latanoprost on endothelin-1 (ET-1) induced impairment of ONH blood flow in rabbits.
Methods: :
Male Dutch rabbits housed under a 12-hour light-dark cycle were used in this study. A quantitative index of blood velocity, squared blur rate (SBR), was determined with the laser speckle method. The impairment of ONH blood flow was induced by intravitreal injection of 5 pmol/eye ET-1. Fifty µL of 0.0015% tafluprost, 0.005% latanoprost or 0.004% travoprost were topically administrated at 120 min or 240 min before ET-1 injection. ONH blood flow was measured at 0, 30, 60 and 120 min after ET-1 injection.
Results: :
The baseline SBR in rabbit ONH was 4.17±0.34. The SBR value decreased to 78.7±4.1 % of baseline at 120 min after ET-1 injection. The topical administration of tafluprost at 120 min or 240 min before ET-1 intravitreal injection significantly inhibited the decrease of ONH blood flow after ET-1 injection. Although the topical administration of travoprost and latanoprost at 120 min before ET-1 injection significantly inhibited the impairment of ONH blood flow, the treatment of these compounds at 240 min before ET-1 injection had no effect on the impairment of ocular blood flow.
Conclusions: :
Prostaglandins inhibited ET-1-induced impairment of ONH blood flow, and tafluprost showed a long lasting effect compared with travoprost and latanoprost. These results expecting that tafluprost has superior effect on ocular circulation improvement.
Keywords: eicosanoids • blood supply • optic flow