Intraocular pressure, retrobulbar anaesthesia and digital ocular massage.

OBJECTIVES To determine the degree of intraocular pressure (IOP) rise following retrobulbar anaesthetic injection as well as the optimal time required for the return of the IOP to the pre-injection level following ocular massage. MATERIALS AND METHODS Using the Perkins hand-held tonometer, the IOP of consecutive adult patients were measured in the operating room before local anaesthetic (3 ml of 2% xylocaine with or without adrenaline) injection; immediately after injection and every minute following ocular massage for the next 5 minutes. RESULTS Twenty-three eyes of 17 patients, aged 23-71 years, were studied. The mean (+/- SD) baseline (preinjection) IOP was 16.6 (+/- 6.8) mmHg. Immediately after the injection the IOP rose by 11.8-80% with a mean of 37.3 +/- 16.8% (95% CI: 30.4-44.2). By 3 minutes the IOP had returned to the pre-injection level. After 3 minutes the IOP had become lower than the pre-injection level (p < 0.05) CONCLUSIONS IOP rise following retrobulbar injection of 3 ml of local anesthetic varies from 11.8-80%. Digital ocular massage lowers the IOP to pre-injection level in 60.2% in 3 minutes; in 5 minutes it lowers the IOP to preinjection level in all eyes and to below pre-injection level 86%.