Effect of hyaluronidase addition to retrobulbar local anesthesia for phacoemulsification on intraocular pressure

Abstract

Purpose The aim of this study was to evaluate the effect of adding hyaluronidase to local anesthetic agents on intraocular pressure (IOP) following retrobulbar anesthesia for patients scheduled for routine phacoemulsification.Patients and methods This is a prospective comparative study that included patients scheduled for routine phacoemulsification. Patients were classified into two groups: group A patients were planned to have retrobulbar blocks with lidocaine 2% and hyaluronidase 20 IU/ml, and group B patients were planned to have retrobulbar blocks with lidocaine 2% only without hyaluronidase. IOP was measured immediately before and 2, 5, and 10 min after retrobulbar anesthesia administration in both groups using a calibrated Tono-pen.Results The study included 60 eyes of 50 patients. The mean preinjection IOP in group A patients (hyaluronidase group) was 16.38±2.41 mmHg, whereas the mean 10-min postinjection IOP was 18.17±3.54 mmHg (P>0.05). The mean preinjection IOP in group B patients (nonhyaluronidase group) was 15.41±2.63 mmHg, whereas the mean 10-min postinjection IOP was 24.34±5.25 mmHg (P<0.001). The mean change in IOP in group A before and after retrobulbar anesthesia (IOP rise) was 1.79±2.96 mmHg, whereas in group B, the mean IOP rise was 8.93±4.74 mmHg (P<0.001).Conclusion Although the addition of hyaluronidase to lidocaine 2% before cataract surgery had no IOP-lowering effect, it also did not cause any significant rise of postinjection IOP and did keep it within the range of the preinjection IOP.