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ORIGINAL RESEARCH article

Front. Neurol.

Sec. Neuromuscular Disorders and Peripheral Neuropathies

Volume 16 - 2025 | doi: 10.3389/fneur.2025.1601911

Comparative Analysis of Onabotulinum Toxin Type-A Injection Techniques in Older Adults with Blepharospasm: A Retrospective Cohort Study

Provisionally accepted
Turan  PoyrazTuran Poyraz1*Özgül  Vupa ÇilengiroğluÖzgül Vupa Çilengiroğlu2
  • 1İzmir University of Economics, İzmir, Türkiye
  • 2Faculty of Science, Dokuz Eylul University, Izmir, Izmir, Türkiye

The final, formatted version of the article will be published soon.

Introduction: Benign Essential Blepharospasm (BEB) is a focal dystonia that can lead to functional blindness in older adults. While Botulinum Neurotoxin (BoNT) is widely utilized in the treatment of BEB, there remains a lack of consensus regarding the optimal injection technique. This study aims to compare the clinical outcomes and measurable scales associated with injections into the Orbicularis Oculi muscle at the Pars Pretarsalis (PPT) and Pars Preseptalis (PPS) regions, assessing their efficacy and side effects. Methods: The study included 32 patients diagnosed with BEB. Two injection techniques utilizing Onabotulinum toxin type-A—PPT and PPS—were compared. The modified Jankovic Scale (mJS) was used to assess the clinical severity and frequency of blepharospasm. At the same time, the Blepharospasm Disability Scale evaluated the associated disabilities. The Schirmer I test was used to assess dry eye symptoms post-BoNT administration. Adverse effects were self-reported, and participants were examined at 1-and 3-month follow-up. Results: Both injection techniques resulted in significant improvements in the mJS severity and frequency scores, as well as the Blepharospasm Disability Scale (p<0.05). Notably, improvements in ocular dryness were particularly pronounced at the 1-month mark (p<0.05). The PPT injection technique displayed a superior safety profile, with the total number of adverse events statistically greater in the PPS group compared to the PPT group (p<0.05). Conclusions: BoNT injections through both PPT and PPS techniques are effective in treating BEB in older adults. However, the PPT technique demonstrates a lower incidence of adverse events, rendering it a preferable choice for clinicians managing BEB.

Keywords: Blepharospasm, Botulinum Neurotoxin, Injection techniques, Aging, Jankovic scale

Received: 31 Mar 2025; Accepted: 06 Oct 2025.

Copyright: © 2025 Poyraz and Çilengiroğlu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Turan Poyraz, turanpoyraz@gmail.com

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