Visual-evoked potentials: assessment of retrobulbar and peribulbar anesthesia.

PURPOSE

To assess the effects of retrobulbar and peribulbar anesthesia on nerve function as detected by visual-evoked potentials (VEPs).

SETTING

University hospital in southern Brazil.

METHODS

In a prospective study, 7 patients had peribulbar anesthesia and 9 had retrobulbar anesthesia for extracapsular cataract extraction. Visual-evoked potentials with pattern reversal and flash stimulation were performed at least 1 month before and 1 month after surgery. Study participants did not have ocular pathology other than cataract. The Lens Classification System III was used to grade the opacities before surgery.

RESULTS

No significant difference was found between preoperative and postoperative evaluations in VEP flash and pattern-reversal amplitude and latency in either group (P >.05). Postoperative amplitude and latency was not significantly different between the peribulbar and retrobulbar groups. Two cases in the peribulbar group had altered wave morphology without clinical manifestation postoperatively. All patients had a final best spectacle-corrected visual acuity of 20/20.

CONCLUSION

Block anesthetic procedures were safely used in cataract surgery, with no clinical sequelae to the optic nerve.