EFFECT OF TOPICAL CARTEOLOL ON TISSUE CIRCULATION IN THE OPTIC-NERVE HEAD

The effect of topical 2% carteolol on tissue circulation in the albino rabbit optic nerve head (ONH) was investigated using a laser speckle tissue circulation analyzer. In the first experiment, the normalized b lur (NB) value, a quantitative index of tissue blood flow velocity in the ONH, intraocular pressure (IOP) blood pressure (BP), and pulse rat e were measured under general anesthesia before as well as 30, 60, 90, and 120 minutes after a 20-mu L instillation of carteolol in one eye and the vehicle in the other eye in a masked, randomized manner. In th e second experiment, one eye of a rabbit received carteolol twice dail y for 20 days and the fellow eye received the vehicle in a masked, ran domized manner. The IOP was measured every 5 days, and the NB in the O NH and IOP were measured before treatment and 2 hours after the last i nstillation on the 20th day. After a single instillation of carteolol, pulse rate showed a maximum reduction of 15%, and IOP in the carteolo l-treated eves showed a maximum decrease of 22%. The NE in the ONH and BP did not show any significant change during the experiment. After 2 0-day treatment with carteolol, IOP showed a maximum decrease of 25% i n the carteolol-treated eyes and 21% in the vehicle-treated eyes. The NE showed a significant increase of 15% (P < 0.01) in the carteolol-tr eated eyes and 11% (P < 0.01) in the vehicle-treated eyes, It was indi cated that long-term topical carteolol increased the blood velocity in the ONH tissue both in the carteolol- and vehicle-treated con tralate ral eyes in albino rabbits. (C) 1998 Japanese Ophthalmological Society .