Comparion of preervative-free bupivacaine v lidocaine for intracameral anetheia: a randomized clinical trial and in vitro analyi Original Reearch Article

Purpoe: To determine whether intracameral bupivacaine hydrochloride 0.5% i a effective a lidocaine hydrochloride1.0% in controlling dicomfort of patient during phacoemulification and poterior chamber intraocular len implantation. In rabbit, corneal endothelial cell function, ultratructure, and viability were evaluated after in vitro perfuion of bupivacaine 0.5%. Method: In a double-maked, controlled trial, 48 eye of 48 patient with uncomplicated age-related cataract were randomly aigned to receive bupivacaine 0.5% or lidocaine 1.0% intracamerally before phacoemulification with a poterior chamber intraocular len. Outcome meaure uch a pain, viual acuity, amount of edation, length of urgery, pupil ize, intraocular preure, corneal clarity, and anterior chamber reaction were compared. In laboratory tudie, paired rabbit cornea were evaluated by endothelial cell perfuion with either bupivacaine 0.5%, bupivacaine 0.5% and glutathione bicarbonate Ringer olution in a 1:1 ratio or bupivacaine 0.5% buffered to a pH of 7.0. The paired control cornea were perfued with glutathione bicarbonate Ringer olution and rate of corneal welling were determined. Cell ultratructure and viability were alo evaluated. Reult: In the randomized trial, there wa no ignificant difference in the pain patient had during urgery or in the early or late potoperative period. No tatitically ignificant difference wa een between the two group in term of pupil ize, intraocular preure, corneal edema, anterior chamber reaction, or viual acuity immediately after the operation or on potoperative day 1. Paired rabbit cornea perfued with bupivacaine 0.5% and bupivacaine 0.5% buffered to a pH of 7.0 welled ignificantly (P < .001, P = .009, repectively), and had corneal endothelial cell damage. Dilution of the bupivacaine 1:1 with glutathione bicarbonate Ringer olution prevented corneal edema and damage to the corneal endothelium. Endothelial cell viability wa alo decreaed after perfuion of bupivacaine 0.5% (P < .001). Concluion: Clinically, bupivacaine 0.5% i a effective a lidocaine 1.0% for anetheia during phacoemulification and poterior chamber intraocular len implantation. However, in vitro perfuion of bupivacaine 0.5% damaged the corneal endothelium of rabbit except when the drug wa diluted 1:1 with glutathione bicarbonate Ringer olution. urgeon who ue 0.2 to 0.5 ml of intracameral bupivacaine 0.5% hould be aware of it potential to caue endothelial cell damage becaue of it lipid olubility. The bupivacaine 0.5% hould be diluted at leat 1:1 with balanced alt olution before intracameral injection, followed immediately by phacoemulification. The urgeon hould enure that the bupivacaine 0.5% i nonpreerved and packaged in ingle-ue vial or flip-top container.