Local anesthetic orbicularis myotoxicity: A possible unrecognized cause of post-blepharoplasty lagophthalmos

Background: Injection of local anesthetics into the upper and lower eyelids is routinely performed during a variety of common surgical procedures, including cosmetic blepharoplasty. Although skeletal muscle injury is a very well documented side effect of virtually all local anesthetics, there are few reported cases of orbicularis myotoxicity despite its common exposure to periocular injections. Post-operative localized and occasionally persistent orbicularis oculi weakness may be presumably attributable to local anesthetic myotoxicity. Methods: A non-randomized retrospective clinical case series identified 32 patients seen in a tertiary care referral oculoplastic practice over a 7-year period. Follow-up ranged from 0.5 to 7 years with an average of 1.3 years. Results: Patients demonstrated varying degrees and duration of orbicularis oculi dysfunction manifesting primarily as lagophthalmos. Although most patients improved with observation alone, 6 of 32 patients did not. Conclusions: Orbicularis oculi dysfunction may result from local anesthetic injections. In most cases, this complication is transient, yet permanent dysfunction can occur. To minimize the risk of developing this complication, local anesthetics should be judiciously administered in low volume and concentration away from the critical pretarsal orbicularis. Additionally, patients should be counseled preoperatively about the potential risks of local anesthetic use. Level of Evidence: Level IV, prognostic / risk study.