Efficacy and safety of intracameral lidocaine as a supplement to topical anesthesia

Purpose: To establish the benefit of nonpreserved intracameral lidocaine 1% as an adjunctive anesthetic agent to topical anethesia for small incision cataract surgery and to determine the agent's safety with respect to corneal toxicity. Setting: Advanced Vision Care, West Hills, California, USA. Methods: A retrospective chart review of cataract surgery performed between January 1995 and March 1997 was done. The efficacy of intracameral lidocaine was determined by comparing the number of topical anesthesia cases (Group 1) and of combined topical and intracameral anesthesia cases (Group 2) that required conversion to a more profound level of local anesthesia, determined by patient discomfort, surgeon discomfort, or both. To determine the presence and bias of a surgical learning curve, Group 1 was subdivided chronologically into two subgroups. Corneal toxicity was assayed by the degree of clinical corneal edema noted by sitlamp examination on the first postoperative day. Results: Six hundred thirty-one charts satisfied the criteria for inclusion; 352 cases (Group 1) had topical anesthesia alone and 279 subsequent cases (Group 2), combined topical and intracameral anesthesia. In Group 1, 42.6% of cases required conversion to some form of additional local anesthesia, whereas in Group 2, less than 1.0% required conversion. In the earlier subgroup, 45.8% of cases required conversion:and in the latter, 34.3%, On the first day after surgery, 88.2% of Group 2 cases and 76.7% of Group 1 cases were free from corneal edema. The difference was statistically significant but probably resulted from a change in phacoemulsification technique from sculpting to chopping in the latter cases, which were performed under combined topical and intracameral anesthesia. Conclusions: Intracameral nonpreserved lidocaine 1% appears to be both efficacious and nontoxic as an anesthetic adjunct in small incision cataract surgery.