Toxicity of intraocular lidocaine and bupivacaine Original Reearch Article

Purpoe To tudy the toxicity of intraocular lidocaine, bupivacaine, and a combination of the two anethetic. Method The right eye of 34 rabbit were divided into eight group, and each wa injected intravitreally with 0.2 ml of lidocaine hydrochloride in a 2%, 1%, 0.5%, or 0.25% concentration, or bupivacaine hydrochloride in a 0.75%, 0.5%, or 0.25% concentration, or a 1:1 mixture of lidocaine 2% and bupivacaine 0.75%. The left eye of four of thee rabbit received an injection of balanced aline olution. Electroretinogram were recorded before injection and 30 minute, 90 minute, 3 hour, 6 hour, 24 hour, and 1 week after injection. The amplitude and the implicit time were analyzed. The rabbit were killed 1 week after injection and the eye evaluated hitologically. Reult No advere clinical reaction and no hitologic abnormality wa oberved in any of the nine group after injection. The a- and b-wave of the electroretinogram in the control group injected with balanced aline olution, and the a-wave of the experimental group that received injection of lidocaine, bupivacaine, or the mixture, were normal. The b-wave of the experimental group demontrated a marked decreae in the amplitude and an increae (P <.05) in the implicit time after intravitreal injection. Electroretinogram repone recovered within 24 hour. Concluion Intravitreal injection of 0.2 ml of lidocaine up to 2%, or of bupivacaine up to 0.75%, and the mixture of lidocaine 2% and bupivacaine 0.75%, induced reverible electroretinogram change in the rabbit retina. No hitologic abnormalitie were oberved.