Intraocular pressure and aqueous outflow after fistulization of Schlemm's canal in the vervet monkey Cercopithecus ethiops.

In the vervet monkey Cercopithecus ethiops Schlemm's canal was opened to the outside by a window through the sclera. The flow of aqueous was collected with sponges and weighed. In jour eyes the drainage ranged from 0.5 to 4.5 \iL per minute at the start. Fifteen minutes later it reached an average value between 0.2 and 2 fiL per minute depending on the animal. In 2 animals pressure in the operated eye toas recorded. When the sclera was opened the pressure decreased only a few millimeters of Hg and remained constant. In both these eyes starting pressure was high, 20 to 30 mm. Hg. In another eye the operation was combined with a perfusion of the anterior chamber. The result shows that there is a lack of communication between the hole in the sclera and distant parts of the canal. Probably this is caused by collapse of the canal near the hole. This also explains the lack of pressure drop when starting pressure was high.