The Effects of Bupivacaine and Lidocaine on the Corneal Endothelium when Applied into the Anterior Chamber at the Concentrations Supplied Commercially

Abstract

Purpose: To investigate the direct toxic effects of bupivacaine HCl 0.5% and lidocaine HCl 2%, two commonly used injectable local anesthetic agents, on the corneal endothelium when applied intracamerally. Methods: Two groups were formed, each consisting of 12 pigmented rabbits, and 0.2 ml of the anesthetic agent were injected intracamerally into the right eyes. The central corneal thicknesses and corneal clarities were evaluated preoperatively and at 3, 6, 9, 12 h and 1, 3, 7 days postoperatively. While the central corneal thicknesses were evaluated by ultrasonic pachymetry, the corneal opacification scored between 0 and 3 was assessed by biomicroscopic examination and photographs. Results: Both bupivacaine and lidocaine caused corneal thickening in the 3- to 12-hour measurements. In addition, there was significant corneal opacification in both groups in the 3-hour and 3-day measurements. The corneal thickening and corneal opacification determined during 3- and 6-hour measurements in the eyes which received intracameral bupivacaine were significantly higher than those determined in the lidocaine-injected group. In both groups, the corneal thickness and corneal clarity scores returned to the preoperative values on the 1st and 7th days, respectively. Conclusions: When applied into the anterior chamber at the concentrations supplied commercially, both bupivacaine and lidocaine cause statistically significant corneal thickening and clinically significant corneal opacification. It should be noted that the injection of these agents into the anterior chamber during the operation at the concentrations supplied commercially may be a potential risk factor for endothelial injury.

Cataract surgery anaesthesia: is topical anaesthesia really better than retrobulbar?

“…Research into the short-and longterm side-effects in the cornea as a result of the anaesthetics used is ongoing (Judge et al 1997;Kadonosono et al 1998;Guzey et al 2002). Whether or not the anaesthetic substance reaches the vitreous and the retina is still in doubt (Liang et al 1998).…”

Toxic anterior segment syndrome: Update on the most common causes

“…Some materials shown to cause TASS include endotoxin; denatured ophthalmic viscosurgical devices (OVDs); preservative and stabilizing agents; heavy metals; residue left behind by substances used during the cleaning and sterilization of instruments; intraocular medications at toxic doses; irrigating solutions with incorrect pH, osmolarity, or ionic composition; and retained OVD or lens cortical material. [2][3][4][5][6][7][8][9] In February 2006, the number of TASS cases reported to the Intermountain Ocular Research Center at the University of Utah, the TASS Center at Emory University, and industry representatives increased significantly. This led to the establishment of an ad hoc TASS Task Force, with funding from the American Society of Cataract and Refractive Surgery (ASCRS), for investigating this outbreak and assisting surgical sites in evaluating their risk for TASS.…”

“…Problems may exist with the products themselves, such as improper pH, composition, or contaminants, 8,[13][14][15] or they may be introduced iatrogenically via improper mixing, dosing, or handling. 9,[16][17][18] Mixing antibiotics into the balanced salt irrigating solution is one practice in which preparation errors could lead to toxic inflammation. Adding antibiotics to the balanced salt solution has unproven efficacy at preventing endophthalmitis and has largely fallen out of favor; however, 21% of the survey respondents in the most recent study interval still reported engaging in this practice.…”

“…It is also critical to remember that although 1.0% methylparaben preservative-free lidocaine has not been shown to cause endothelial toxicity when used intracamerally during cataract surgery, even nonpreserved lidocaine at a concentration of 2.0% or higher has been known to cause significant corneal thickening and opacification postoperatively. 9,16 Four percent to 5% of survey respondents reported using lidocaine intracamerally at a concentration of 2.0% or greater.…”

Ophthalmic loco-regional anaesthesia: Reducing discomfort during injection

“…Chang et al, 11 for example, have demonstrated in a rabbit model that local anaesthetic drops can cause dose and time-dependent cytotoxicity, usually within the first minute of contact with corneal endothelium. Guzey et al 12 have demonstrated the risks of corneal endothelium damage following the application of topical anaesthesia in patients.…”