J Korean Ophthalmol Soc.  2023 Sep;64(9):845-850. 10.3341/jkos.2023.64.9.845.

Corneal Topographic Changes after Botulinum Toxin-A Injection in Patients with Essential Blepharospasm

• Kim S
• Ahn JH

• KMID: 2545761
• DOI: http://doi.org/10.3341/jkos.2023.64.9.845

Abstract

Purpose
To compare the corneal topographic change before and after botulinum toxin A injection in patients with essential blepharospasm.
Methods
From September 2015 to December 2020, we enrolled total 20 patients, 40 eyes diagnosed with essential blepharospasm. We estimated the corneal refractive power and astigmatism before and after Nabota^® (Daewoong Co. Ltd, Seoul, Korea) botulinum toxin injection at 1 and 3 months using iTrace^® Topography (Software version 4.2.1., Tracey technology Inc., Houston, TX, USA). Corneal refractive power was analyzed in superior, inferior, nasal and temporal location at 1 mm, 3 mm zone. Also, steep and flat keratometry, astigmatism was measured by topography.
Results
Corneal refractive power showed significant difference in superior and inferior location of 1 mm zone at 1 month after botulinum toxin injection (p = 0.038, p = 0.042). There was no significant difference in all four locations of 3 mm zone. At 1 month after toxin injection, steep keratometry was only significant reduced (p = 0.046) and with-the-rule astigmatism was shifted to against-the-rule astigmatism. At 3 months after toxin injection, keratometry and astigmatism was resolved to before toxin injection.
Conclusions
At 1 month after Nabota^® (Daewoong Co. Ltd) botulinum toxin injection, corneal refractive power at vertical axis was flattened and steep keratometry was significantly reduced. At 3 months after toxin injection, corneal topographic change was changed to before toxin injection.

Keyword

Botulinum toxin A, Corneal curvature, Corneal topography, Essential blepharospasm