Myotomy In Situ for Essential Blepharospasm Refractory to Botulinum Toxin.

[BACKGROUND] Full myectomy is recommended for benign essential blepharospasm (BEB) refractory to botulinum toxin (BT) treatment, but long-term swelling, scar contracture, hollow appearance, and unnatural contour of the eyelids are common postoperative complications. We present myotomy in situ to minimize these adverse outcomes.

[METHODS] The redundant eyelid skin with its underlying muscle is resected first, and myotomy in situ is performed by completely cutting the residual orbicularis oculi muscles into multiple cubes and down to the subcutaneous layer, and then cutting the procerus and corrugator muscles down to the periosteum. Patient demographics, medical treatment history, BT injection history, blepharoptosis correction techniques, associated surgical procedures, and aesthetic outcomes were analyzed. Preoperative and postoperative BT injection dosage and frequency, as well as modified disability scores, were compared using paired Student t tests.

[RESULTS] Twenty-five patients underwent this technique. Their average ± SD age was 64.4 ± 8.9 years, with average postoperative follow-up occurring 17.0 ± 8.0 months. Associated diseases included blepharoptosis (88%) and apraxia of lid opening (44%). There were no postoperative hematoma, seroma, scar contracture, and depressed hollow eyelid contours. Preoperative to postoperative assessments revealed improvements in mean BT injection interval (10.4 ± 2.1 to 14.6 ± 2.9 weeks, P < 0.001), BT injection dosage (44.4 ± 13.3 to 28.1 ± 6.7 units, P < 0.001), and modified disability score (15.3 ± 3.0 to 2.8 ± 2.2, P < 0.001). All patients were highly satisfied with functional and aesthetic surgical outcomes (4.5 ± 0.6 on Likert scale).

[CONCLUSIONS] Myotomy in situ is effective for patients with BEB who are refractory to BT treatment, with therapeutic benefits similar to that of full myectomy with the ability to maintain favorable cosmetic results. Relative high incidence of blepharoptosis and apraxia of lid opening in patients with refractory BEB was reported. Simultaneous correction of the ptosis can further optimize outcomes.