The Practical Use of AbobotulinumtoxinA in Aesthetics

Accommodation amplitude change after cosmetic use of the botulinum toxin in the upper face

PURPOSE

Cosmetic botulinum toxin A (BoNT-A) injections are increasing worldwide. Adverse effects need to be evaluated in more detail for BoNT-A regulations. This study aims to assess the anticholinergic effect of BoNT-A on accommodation amplitude (AA) after upper face application.

METHODS

Twenty patients aged between 20 and 45 years were recruited in this prospective, interventional study. Abobotulinum toxin A of 500 units was diluted with 3 ml saline and injected into the forehead, glabellar and periorbital area. AA was measured with both the push-up and minus-lens techniques before and after two weeks of the injections. T-test for normally distributed variables was applied for the comparison of the results.

RESULTS

The study group comprised 18 women and 2 men with a mean age of 33.9 ± 8.59. AA decreased significantly after two weeks of the injection. In the push-up test, AA was 9.18 ± 4.72 D before BoNT-A injection and decreased to 7.11 ± 3.02 D after the injection (p < 0.001). In the minus lens test, AA reduced from 5.86 ± 2.24 D to 5.24 ± 2.06 D after BoNT-A injection (p < 0.001). Refraction did not change in any of the participants.

CONCLUSION

The present study showed that cosmetic upper face BoNT-A injections reduced AA. However, this reduction did not result in any significant symptomatic effects in the patients. These findings suggest that while BoNT-A injection has a measurable impact on the ciliary muscle or its parasympathetic innervation, it may not lead to noticeable clinical outcomes.

The Effect of Climate on the Dose Requirements of Botulinum Toxin A in Cosmetic Interventions

BACKGROUND

Botulinum toxin A to the glabella is a popular cosmetic intervention. Functional musculature differences may arise from chronic behavioral adjustment to high sun exposure levels, requiring greater doses. This could affect clinical practice globally. This study investigated the effect of climate on real-world doses.

METHODS

The authors conducted a comparative cohort study using data from a registry from a single provider practicing across two centers: the United Kingdom and Malta. They classified one center as low sun exposure (United Kingdom winter month treatment) and the other as high sun exposure (Malta summer months). Patients were followed up once every 3 weeks and received top-up doses until full clinical paralysis was achieved. To standardize the comparison, the study included only women aged 35 to 60 years undergoing glabellar botulinum toxin treatment by experienced clinicians following standard procedures from 2012 to 2019. Smokers, those not seeking maximal paralysis, those documented as not compliant with posttreatment advice, those with colds or fevers, and those with broken cold supply chains were excluded. Univariable and multivariable analyses were undertaken.

RESULTS

A total of 523 patients were included: 292 "high-sun" patients and 231 "low-sun" patients. Mean total doses were significantly higher in the high-sun group (29.2 units versus 27.3 units; P = 0.0031). When correcting for age in multivariable analysis, the low-sun group still had lower total dose requirements ( P = 0.00574).

CONCLUSION

Patients injected with glabellar botulinum toxin in high-sun climates may have significantly increased dose requirements to achieve maximal paralysis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

[New botulinum toxins for aesthetic dermatology : A comprehensive review]

Facial rejuvenation is gaining immense popularity among patients and clinicians. Botulinum toxins derived from bacteria are well-tolerated options as minimally invasive interventions for facial rejuvenation or other aesthetic procedures. These products have revolutionized aesthetic treatments. Several types of botulinum toxins (BoNT) are available. Currently type A and B are clinically used and only BoNT‑A products are approved for use for cosmetic indications in the Germany and the United States. Each product is unique in terms of its composition. Understanding the various BoNT‑A products is essential in choosing the optimal treatment for our patients. In this article we discuss different BoNT‑A products used for aesthetic intervention.

The mechanisms of action and use of botulinum neurotoxin type A in aesthetics: Key Clinical Postulates II

BACKGROUND

The literature on botulinum neurotoxin type A (BoNT-A) is extensive, often contradictory, and confounded by a competitive market of products and research attempting to distinguish brand individuality.

METHODS

A comprehensive review of literature on the principles of BoNT-A in aesthetics as well as clinical examples.

RESULTS

In 2017, the Eight Key Clinical Postulates were formulated as a guide for the aesthetic practitioner in understanding BoNT-A pharmacodynamics and to compare different toxins. These are now updated to include (a) All type A toxins act identically; (b) The mathematical relationship between toxin and receptor is the basis of efficacy, and clinical efficacy is influenced by molecular potency and patient attributes including muscle mass, gender, age, and ethnicity; (c) Efficacy, onset, and duration are functions of "molecular potency" defined as the number of active 150 kDa molecules available for binding; (d) "Molecular potency" is difficult to objectively quantify for commercially available toxins; (e) Up to a point, increased molecular potency decreases time to onset and increases duration of effect, and the "Molecular Potency Quotient" is a construct for comparing molecular potency commercial cost; (f) The area of effect of a toxin injection is dependent upon molecular potency, diffusion (passive), and spread (active); (g) Differing reconstitution volumes; and (h) Increased number of injection sites can affect spread, onset, and duration of effect.

CONCLUSIONS

The principles of BoNT-A use in aesthetics are complex yet understandable as outlined in the framework of the updated Eight Key Clinical Postulates and serves as a useful tool for providing the most effective treatment and interpreting research on present and future toxin formulations.

Advanced Techniques for the Use of Neurotoxins in Non-Surgical Facial Rejuvenation

BACKGROUND

Neurotoxins initially were used to treat hyperfunctional rhytids of the face, but now have been expanded to improve facial shaping, correct facial asymmetry and even improve skin texture and tone.

METHODS

The clinical approach to non-surgical facial rejuvenation is approached into four anatomical regions: the upper face, midface, lower face and neck.

RESULTS

The key muscles of the upper face include frontalis, orbicularis oculi, corrugator supercilii, procerus, depressor supercilii and temporalis. The muscles in the midface to be discussed include the levator labii superioris, levator labii superioris alaeque nasi, depressor anguli oris, depressor septi nasi and nasalis. Treatment of the lower face focuses on the orbicularis oris, mentalis, depressor anguli oris and masseter muscles. Finally, treatment of the neck region will be reviewed with emphasis on platysmal bands and necklace lines as well as the Nefertiti lift.

CONCLUSIONS

Non-surgical facial rejuvenation using neurotoxins should be performed safely and effectively in order to avoid and treat complications.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Abobotulinum toxin A for periorbital facial rejuvenation: impact on ocular refractive parameters

CLINICAL RELEVANCE

Botulinum toxin is commonly used for cosmetic facial rejuvenation and can result in pain at the injected site, bruising and ecchymosis, erythema and oedema, headache, diplopia, blurred vision, focal facial weakness. This study evaluates the impact of botulinum toxin on refractive error and binocular vision.

BACKGROUND

Botulinum toxin (trade name: Dysport) is a neurotoxic protein which is made from a Gram-positive anaerobic bacterium known as Clostridium botulinum. In this study, we aimed to evaluate the impact of Dysport injection on refractive error, near point of accommodation and convergence, and palpebral fissure height.

METHODS

Twenty-eight subjects were treated for facial wrinkles, using Dysport. A 500-unit vial of Dysport was diluted with 2.5-ml preserved normal saline, and injected doses were 30-units for crow's feet, six units for lower eyelid wrinkles, 25 to 50-units for glabellar lines (five points), and 20 to 40 for forehead creases on four points. The refractive error, near point of accommodation and convergence and palpebral fissure heights were assessed before and two weeks after injection.

RESULTS

The participants comprised 23 women and five men at a mean age of 53.51 ± 14.1-years. The means of the equivalent sphere before and after injection were -0.07 ± 1.34 and -0.08 ± 1.35 (p = 0.36). The means of near point of accommodation monocularly before and after injection were 29.75 ± 6.16-cm and 26.75 ± 6.00, respectively. The means of near point of convergence before and after injection were 16.03 ± 5.27-cm and 15.55 ± 6.14, respectively (p = 0.30). The means of palpebral fissure height before and after injection were 10.33 ± 1.69-mm and 10.20 ± 1.46-mm, respectively. The changes in equivalent spherical refractive error, binocular near point of accommodation and convergence were not statistically significant.

CONCLUSION

Dysport injection for the correction of upper face animation lines, if performed at the appropriate sites and the appropriate concentration, has no significant impact on refractive error, near point of accommodation and convergence, and palpebral fissure height.

Botulinum neurotoxin formulations: overcoming the confusion

Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity). In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed.