Prostaglandin and neurogenically mediated ocular response to laser irradiation of the rabbit iris

Biphasic Intraocular Pressure Response to Laser Irradiation of the Iris in Rabbits

“…The IO P elevation has been partly attributed to an elevation o f P G levels in the aqueous humor [8,9], to clogging o f the tra becular meshwork by debris and protein [10,11], and to inflammation o f the trabecular meshwork [10]. In animals, acute rises o f the IO P have been reported after laser irradiation o f the iris [8,12,13]. However, little attention has been paid to the hypotony after laser irra diation of the iris.…”

“…However, it is reasonable to postulate that the IO P change following laser iridotomy that we observed is due to P G , at least in part, because the rise o f IO P after laser irradiation o f the iris [21] and after laser capsulotomy [22] was attenuated by indomethacin. However, the rise o f IO P after laser irradiation o f the iris was only par tially blocked by indomethacin, but was al most completely abolished by a combination o f indomethacin and tetrodotoxin [13]. More over, the intravitreal injection o f endothelin-1 produced a biphasic IO P response, consisting o f an initial rise o f 1-2 h and a subsequent prolonged reduction [23].…”

THE EFFECTS OF SENSORY DENERVATION ON THE RESPONSES OF THE RABBIT EYE TO PROSTAGLANDIN E1, BRADYKININ AND SUBSTANCE P

“…The latter would, however, block axonal conduction and so prevent spread of the stimulus. Thus in the interpretation by Unger, Cole & Bass (1977) of the response to laser irradiation of the iris, the 'neurogenic component' blocked by local anaesthetics may be that part of the response which is propagated by axon reflex, whereas the residual response may be that part due to the direct focal action of prostaglandins on the nerve terminals. It was considered that should substance P act in the same way as the putative mediator, then the presence or absence of functional sensory nerves should have no bearing on the nature or magnitude of the response as they would on that to PGE1 or bradykinin, which seem to require their presence.…”

An Experimental Steroid Responsive Model of Ocular Inflammation in Rabbits Using an SLT Frequency Doubled Q Switched Nd:YAG Laser

“…Effects of laser application to iris tissue with lasers other than the SLT have been reported previously. [23][24][25][26][27][28] To the best of our knowledge, this is the first report of the effects of application of SLT laser directly to the iris tissue. Compared to argon laser, SLT laser is devoid of coagulative and mechanical tissue damage when applied to the trabecular meshwork of eye bank eyes.…”