[Effect of severing trigeminal nerve on intraocular pressure and pupil in rabbits]

Changes of intraocular pressure (IOP) and pupil were observed through severing trigeminal nerve (TN), and the possible effect on TN on regulation of IOP was investigated in 5 rabbits. When TN was severed, the mean IOP at the same side was sharply and significantly elevated, being almost 2-fold of that before the procedure (P < 0.01). After the procedure, the mean elevated IOP decreased rapidly. The mean IOP at the end of the procedure was 0.28kPa higher than that before the procedure, and the IOP difference between pre- and post-procedure was not significant (P > 0.05). There was no significant difference in the comparison between the mean IOP after the procedure for 2 weeks and that before the procedure (P > 0.05). On the other hand, the mean diameter of pupils during and at the end of the procedure was significantly decreased (P < 0.01), when compared with that before the procedure, and afterward it gradually recovered. The above findings show that the rapid and significant reactions of IOP and pupil during the procedure are possibly affected by the actions of some neuropeptides in the TN5 suggesting that TN, participate in the regulation of IOP.