Intraocular haemorrhage as a complication of pneumoencephalography

The ocular fundi of 20 patients were examined before and after pneumoencephalography. In four of these, fresh venous retinal haemorrhages were seen, and a further patient had developed an exudate. Possible reasons for a rise in retinal venous pressure include bodily inverting the patient, compression of the thorax, the use of positive pressure respiration, and the air injection itself. It may be advisable to take steps to limit the effects of such possible causative factors.