To the Editor.
—Drs Zavon and Fichte1 suggested the use of an eye anesthetic, such as 0.5% proparacaine hydrochloride, in the symptomatic treatment of trigeminal neuralgia. They relieved the pain in two different patients with only two drops of topically applied anesthetic. Some of your readers will experiment with this treatment. Therefore, it may be important to emphasize that all local anesthetics can produce a toxic keratopathy with repeated application.2-4 Furthermore, all local anesthetics prevent the healing of corneal abrasions, in part by interfering with corneal epithelial mitosis and cellular migration.5 This caution is not meant to discourage attempts to initiate a double-masked study to test this fascinating observation.
Flach AJ. Trigeminal Neuralgia Relieved by Optical Anesthesia. JAMA. 1991;266(12):1649. doi:10.1001/jama.1991.03470120051024