Purpose: To evaluate an indwelling retrobulbar catheter for repeatable postoperative retrobulbar injections of local anesthetics for titratable analgesia after intraocular surgery.
Methods: The prospective study included all 124 patients (124 eyes) who consecutively underwent retinal or cyclocryocoagulation (n = 22), pars plana vitrectomy, or retinal detachment surgery (n = 102), and who were operated on by the same surgeon with local anesthesia within a period of 12 months. Using commercially available retrobulbar needles with a diameter of 0.60 mm or 0.80 mm and a length of 38 mm, 5 ml of mepivacaine 2% with hyaluronidase were injected. Through the same needle, a 28-gauge commercially available flexible catheter was introduced into the retrobulbar space, the needle was withdrawn, and the catheter was fixed in place. When the patients started to feel pain after surgery, 2 ml of mepivacaine 2% or 2 ml of bupivacaine 0.75% were reinjected through the catheter. The catheter was removed 24 to 72 hours after surgery.
Results: Because of increasing pain in the postoperative period, 93 patients (93 of 124, or 75%) received a reinjection 4.2+/-2.0 hours after the preoperative injection. Seventy patients received a second reinjection after an additional 2.7+/-1.9 hours, and 42 patients received a third reinjection 3.1+/-2.0 hours later. After each reinjection, the patients became pain free. Removal of the catheter after surgery was unremarkable.
Conclusions: An indwelling retrobulbar catheter for repeatable postoperative injection of short-acting local anesthetics is useful and effective for titratable postoperative analgesia after intraocular surgery, and it allows patients to avoid the side effects of systemic analgesics and sedatives.