Which is better retrobulbar or sub-tenon's capsule local anesthesia?

ABSTRACT

Subtenon's capsule injection of local anesthia is well known in operations of anterior segment but we are in need for more research in our university to use it in vitreoretinal surgery. Sixty patients received either retrobulbar or subtenon's injection [5 ml of 0.75% ropivacaine] to undergo vitreoretinal surgery. The level of intraoperative pain was evaluated twice using visual analogue scale. Also the [start time] was evaluated in both groups. Local anesthesia in both groups was effective in pain prevention [VASsurgery and next morning. Next day VAS was recorded for remembering pain during operation, in retrobulbar group [mean = 1.4 +/- 2.6 median 1] while in subtenon's group [mean = 1.1 +/- 1.6 with median 1]. Start time [time since start of injection until starting surgery] was evaluated in both groups. In retrobulbar group [mean = 12 +/- 4.5 with median 13min.] [P = 0.16]. Subtenon's capsule [mean = 13 +/- 5.4 with median 14 min.] [P = 0.05]. These were significant difference between both groups. Extra doses of local anesthesia were evaluated in both groups, in retrobulbar group 11 pat. of 31 needed extra doses, but in subtenon's group only 9 from 29 patients needed extra doses with insignificant difference. As regard i.v. sedatives, in retrobulbar group about 28 patients needed i.v. sedation but in subtenon's group only 21 patient needed i.v. sedation with insignificant difference. Subtenon's capsule injection is quite effective in pain control as compared to retrobulbar local anesthia in vitreoretinol surgery