Ultra-Long-Term Therapy of Benign Essential Blepharospasm with Botulinumtoxin A-30 Years of Experience in a Tertiary Care Center

Abstract

Aim of this study was to investigate the long-term results of botulinum toxin A (BoNT-A) injections for the treatment of benign essential blepharospasm (BEB) and to report our experience with (ultra-)long-term treatment with onabotulinumtoxin-A. We conducted a retrospective cross-sectional analysis at a university hospital. Patients with BEB and BoNT-A treatment were assigned to the Total Blepharospasm Group, patients with ≥21 onabotulinumtoxin-A injections to the Ona Long-Term Group. The Total Blepharospasm Group (n = 1940) included 33,933 BoNT-A injections. The age of patients at symptom onset was (mean ± SD) 58.0 ± 13.1 years, and 70.4% were female. The Ona long-term group (n = 234) included 10,632 onabotulinumtoxin-A injections. In this group, patients received 45.4 ± 22.9 injections with a mean dose of 22.2 IU ± 0.5. The duration of treatment was 12.6 ± 5.4 years, ranging from 2.9 to 30.0 years. The effect-duration-dose quotient did not change during long-term treatment. The observed side effects were comparable in type and frequency to other studies, even with the (ultra-)long treatment with onabotulinumtoxin-A. Our results, based on one of the largest patient populations and a treatment duration of up to 30 years, impressively demonstrate that onabotulinumtoxin-A is a safe and effective therapy for essential blepharospasm, even in the ultra-long term.

Keywords: adverse events; blepharospasm; botulinum toxin; long-term; outcome.

Figure 1

Doses of onabotulinumtoxin A administered over the long term, with time represented by consecutive number of injections. The box of a box-plot represents the quartiles (25%- and 75% percentile) of the empirical distribution. The wiskers show values up to the 1.5 fold of the inquartile range above and below the box. Values outside this range are represented by circles.

Figure 2

Subjective effect duration of onabotulinumtoxin A administered over the long term, with time represented by consecutive number of injections. Values outside the 1.5 fold of the inquartile range above the box range are represented by circles.

Figure 3

Effect–duration quotient under long-term treatment with onabotulinumtoxin A. Time is represented by consecutive number of injections. Values outside the 1.5 fold of the inquartile range above the box range are represented by circles.

Figure 4

The percentage of double vision in relation to all 10,632 onabotulinumtoxin A injections administered over the long-term course increased significantly (p < 0.001). Time is represented by consecutive injection numbers.

Figure 5

The percentage of ptosis in relation to all 10,632 onabotulinumtoxin A injections administered over the long-term course remained stable (p = 0.567). Time is represented by consecutive injection numbers.