[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
March 1991

Histologic Features of Human Orbicularis Oculi Treated With Botulinum A Toxin

Author Affiliations

From the Department of Neurology (Drs Harris and Alderson) and the Division of Oculoplastic Surgery, Department of Ophthalmology (Dr Anderson), University of Utah School of Medicine, Salt Lake City; Neurology Division, Veterans Administration Medical Center, Salt Lake City (Dr Alderson and Mr Nebeker); and the Department of Ophthalmology, University of Texas Medical Branch, Galveston (Dr Holds). Dr Holds is currently with Bethesda Eye Institute, St Louis (Mo) University; Mr Nebeker is currently with the University of Pennsylvania School of Medicine, Philadelphia.

Arch Ophthalmol. 1991;109(3):393-395. doi:10.1001/archopht.1991.01080030095046

• To evaluate muscle histologic features in humans following therapeutic botulinum toxin injections, we studied orbicularis oculi from 11 patients with blepharospasm; nine had previously received botulinum toxin injections and two had not. All muscles had comparable variability in muscle fiber diameter, with no necrosis, inflammation, denervation, or consistent alterations in muscle fiber internal architecture. Botulinum toxin produces no persistent histologic changes in human muscle fibers.