[The effect of repeated adrenaline application on intraocular pressure and pupil in the rabbit (author's transl)]

The effect of single and repeated topical application of adrenaline on the intraocular pressure and pupil in the rabbit eye was studied using a 2% adrenaline borate and a commercial preparation of 2% adrenaline hydrochloride. On the first day, the hydrochloride gave a more pronounced pressure reduction and pupil diladation than the borate. This was found to be due to the benzalkonium chloride in the chloride preparation causing a better permeability of the adrenaline into the eye. From the second to the fifth day of adrenaline treatment a marked pressure decrease was found from the previous application of the day before. The following adrenaline application gave a hypertensive phase of intraocular pressure lasting two or three hours and a subsequent hypotensive phase lasting more than 24 hrs. The pupil diladation on the second and following days of treatment was not essentially different from the first day considering the observation period of two hours. The hypertensive phase could not be influenced by intravenous or intramuscular propranolol, however, the topical application of propranolol inhibited it completely. Some aspects of adrenergic regulation of the intraocular pressure are discussed.