Abstract Listings 2026

Purpose

To evaluate short-term changes in corneal epithelial thickness mapping and corneal topography parameters following botulinum toxin injection in patients with blepharospasm and hemifacial spasm.

Methods

This prospective observational study included 10 patients (6 females, 4 males) with facial dystonia, including 3 patients with blepharospasm and 7 patients with hemifacial spasm. Corneal epithelial thickness mapping and Scheimpflug-based corneal tomography were performed before and 1 month after botulinum toxin injection. Evaluated epithelial map parameters included central, inner-ring, and outer-ring epithelial thicknesses. Topographic parameters included central corneal thickness (CCT), anterior chamber depth (ACD), iridocorneal angle, keratometric values, anterior and posterior astigmatism, keratoconus screening indices, and posterior elevation measurements.

Results

Mean central epithelial thickness decreased from 48.0 ± 2.6 µm preoperatively to 46.0 ± 2.6 µm postoperatively. Mean inner-ring epithelial thickness decreased from 46.0 ± 2.9 µm to 44.6 ± 2.7 µm, while mean outer-ring epithelial thickness showed minimal change (43.9 ± 3.4 µm vs 43.4 ± 2.9 µm). Mean central corneal thickness remained stable before and after treatment (521.4 ± 24.5 µm vs 521.4 ± 25.9 µm). Keratometric and posterior corneal parameters demonstrated no marked postoperative alterations overall. No clinically significant progression in keratoconus screening indices was observed during follow-up.

Conclusion

Botulinum toxin treatment in patients with blepharospasm and hemifacial spasm was associated with mild reductions in central and inner corneal epithelial thickness at 1 month, while overall corneal topographic parameters remained largely stable. Corneal epithelial mapping may provide a sensitive tool for detecting subtle ocular surface changes following botulinum toxin therapy.

Additional Authors

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