Systemic levels of lidocaine after intracameral injection during cataract surgery

Purpose: To evaluate the systemic concentrations of lidocaine after intracameral injection of a 1% solution during cataract surgery and the safety of this application mode. Setting: Department of Ophthalmology, Medical University of Lubeck, Lubeck, Germany. Methods: This prospective study included 10 patients who had phacoemulsification and posterior chamber lens implantation with a self-sealing scleral tunnel incision. Topical anesthesia was achieved using cocaine 10% eyedrops combined with 0.5mL of unpreserved lidocaine 1% injected into the anterior chamber. Blood samples were taken from all patients at predetermined intervals before and during the procedure. Consecutive analysis for lidocaine was performed with gas chromatography. Results: In all samples, serum lidocaine concentrations were below a minimum detectable level of 100 ng/mL. No local or systemic intraoperative or postoperative complications were noted. Conclusions: Intracameral injection of 0.5 mL lidocaine 1% revealed no systemic therapeutic concentrations. In patients in whom other forms of needle- delivered local anesthesia are contraindicated, intracameral injection of lidocaine should be considered to enhance topical anesthesia.