Abstract
Tonometry in patients undergoing surgery with cardiopulmonary bypass (heart-lung machine) showed that a decrease in arterial pressure to 57 mm Hg during the extracorporeal circulation – contrary to expectation – did not cause a decrease in intraocular tension. On the contrary other factors seem to have become active that effected an increase in intraocular tension during the extracorporeal circulation. From the postoperative ophthalmological examination we can infer that the increase in intraocular pressure during the cardiopulmonary bypass usually does not have destructive consequences for the eyes. In 2 cases, however, blocking of the cerebral blood flow was observed, which led to extreme ocular hypertension and a permanent decrease in central vision.