Effect on intraocular pressure of retrobular injection of xylocaine with and without adrenaline.

The changes in IOP were registered in two groups, each comprising 30 patients, after a retrobulbar injection of Xylocaine and Xylocaine-adrenaline respectively. No significant difference between the mean values of the initial pressures and the IOP during the following ten min could be proved in either of the groups, but in several individual cases there was a considerable and unpredictable change in IOP following the injection. After ten min this effect was still often present but less pronounced. The change in IOP was significantly greater when adrenaline was used. As a result of these findings the authors have been inclined to cease using adrenaline in retrobulbar anaesthesia for intraocular surgery of short duration.