Objective: In this article authors focused to influence the physiologic IOP values after application of the aminoacid 10% L-lysine.2HC1.2H2O in 0.5 % Timoptol eye drops mixture in experiments. Methods: 0.5% Timoptol, followed by 10% L-lysine.2HC1.2H2O and mixture of 10% L-lysine.2HC1.2H2O with 0.5 % Timoptol was instilled weekly into the left conjunctival sac of 5 adult rabbits (females of the New Zealand White species). The IOP and pupilar diameter were measured in 5,15,30,60,120,180 and 240 min. after instillation. The right eye was ušed as control. Results: In experiments authors observed that: a) the aminoacid 10% L-lysi-ne.2HC1.2H2O is without influence on the physiologic value of the IOP; b) 0.5 % Timoptol compared with control eye nonsignifícantly decreased the rabbit IOP; c) after instillation of 10% L-lysine.2HC1.2H2O and 0.5 % Timoptol mixture the IOP showed decrease of the physiologic IOP in two periods. The initial non-significant period of the IOP decrease was measured after application up to the 60th min. The identical values were also in the control eye. However, the major decrease of the IOP compared with control eye was observed during the second period starting from 60th min. up to the end of experiments (to the 4th hour) after instillation of this mixture. The mean value of this significant decrease was 3.3 torrs of the physiologic IOP value showing regular and linear effecti-vity in the experimental eye. In the control eye the second period was without decrease of the IOP. Conclusions: The results demonstrate that the Timolol alone decreased the physiologic IOP no significantly, the aminoacid L-lysine.2HCl.2H2O is without influence on the physiologic value of the IOP. In experiments we confirmed that in a mixture of aminoacid L-lysine.2HCl.2H2O with antiglaucomatic 0.5 % Timoptol a new substance was created, a new "bio-antiglaucomatic", respon-sible for more significant decrease of the physiologic IOP.

        Key words: the rabbitt IOP influence with L-lysine.2HC1.2H2O and Timolol mixture, the effectivity of the "bio-antoglaucomatic" on physiologic IOP of the rab-bits