[Change in intraocular pressure after peribulbar and retrobulbar injection: practical sequelae].

BACKGROUND

To assess the effect on intraocular pressure of peribulbar and retrobulbar anaesthesia before standard cataract surgery and to study the efficacy of ocular compression.

METHODS

In study group 1,29 eyes of 29 patients undergoing cataract surgery each received peribulbar injections consisting of 9 ml of anaesthetic from an inferotemporal site through the skin. IOP values were measured immediately before and after the injections and then after 10 minutes of external ocular compression. In study group 2, 30 eyes of 30 patients undergoing cataract surgery received retrobulbar injections of local anaesthetic as above but through the conjunctiva and a facialis blockade. IOP values were measured immediately before and after the injections and then after 10 minutes of external ocular compression.

RESULTS

The mean immediate increase in IOP induced by the injections was 16,10 (95% confidence interval 11,58/20,62) mm Hg in study group 1 and 1,76 (CI: 0.76/2.76) in study group 2. After The mean variation in IOP after 10 minutes of ocular compression was +0.97 (CI: -1.06/+3) mm Hg in group 1 and -2.97 (CI: -3.98/-1.96) mm Hg in group 2.

CONCLUSIONS

The peribulbar injection cause a very important increase of the IOP immediately after the injection: the retrobulbar injection did not. An ocular compression of 10 minutes is effective in reversing this rise. The implications for clinical practice are discussed.