Abstract
Purpose::
This study is designed to determine the efficacy and safety of botulinum toxin A (BOTOX) injections after 10 years of treatment.
Methods::
Medical records of 64 consecutive patients who received BOTOX injections between 10/2005 and 05/2006 were retrospectively reviewed. Patients treated for more than 10 years with at least 1 injection each year were included in the study. Clinical diagnoses, patient characteristics, injection dates and doses, peak effect durations, and adverse effects were collected. Response ratings were obtained using a subjective self-evaluation scale of 0-4. Statistical analyses were conducted with SPSS 11.0 package. Wilcoxon signed-rank test was used for computations (p<0.05 accepted as statistically significant).
Results::
Thirty-two out of 64 patients (mean age, 57.6±12.3 years; 25 female) met the inclusion criteria. The diagnoses were benign essential blepharospasm (BEB) (n=21), hemifascial spasm (HFS) (n=9), myokymia (n=1), and Bell’s palsy (n=1). Only one eye of each patient was evaluated for statistical analysis. The mean follow-up duration was 14±4 years (range; 10-19.5), with a mean of 44.7±19.3 total visits. The patients received 3.5±1.5 and 3.3±1.1 treatments per year during first and the last years, respectively (p=0.253). A higher mean injection dose units per visit (26.4±10.3) was used in the last year, compared to first year (22.6±7.6) (p<0.005). The mean peak effect durations for the first and last years were, 12.6±7.1 and 14.5±7.1 weeks, respectively (p=0.116). There was no difference in response ratings for the first (3.3± 0.6) and last (3.4± 0.5) years (p=0.395). Most common adverse effects noted during the mean 14 years of follow-up were ptosis (13 from 12 patients), lagophthalmos (12 from 11 patients), and dry eye (12 from 12 patients). Twelve of these events were reported during the 1st year, 18 between 1 and 10 years, and only 7 events after 10 years. Other rare side effects were diplopia (n=4), ectropion (n=3), hematoma (n=2), photophobia (n=2), and continuous nasal discharge (n=1). None of these reactions were life-threatening.
Conclusions::
BOTOX provides a satisfactory and safe long-term treatment after 10 years of continuous use. Similar efficacy of treatment, requiring higher doses of injections, comes with diminished adverse effects.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: systems/equipment/techniques • drug toxicity/drug effects