A Case of Reactivation of Herpes Simplex Virus Corneal Endotheliitis Following Periocular Botulinum Toxin A Injection.

Botulinum toxin type-A is a standard treatment of a variety of neurological disorders. Here, the authors report a rare ocular adverse effect after periocular Botulinum Toxin-A injection for hemifacial spasm. Three weeks after the injection, facial spasm was relieved, but the patient had dimness of vision OS. Examination revealed corneal edema, anterior-chamber reaction, keratic precipitates, and elevated intraocular pressure in OS suggesting reactivation of herpes simplex viral endotheliitis with trabeculitis. The case was successfully treated with oral acyclovir (400 mg) and topical fluorometholone 0.1% for 6 weeks. Pre- and posttreatment anterior segment optical coherence tomography clearly demonstrated the evidence of keratic precipitates. To the best of the authors' knowledge, this is the first report of herpetic reactivation in the form of corneal endotheliitis with trabeculitis after Botulinum toxin-A injection. The aim of reporting this case is to alert the clinician about the possibility of such consequence of botulinum toxin injection.