Ординатура / Офтальмология / Английские материалы / Oculoplasty and Reconstructive Surgery Made Easy_Garg,Touky, Nasralla_2009

Periocular Applications of Botulinum Toxin 549

Table 2: Botulinum toxin a concentration with various volumes of diluent used

Table 3: Essential equipment for botulinum toxin applications (Fig. 1)

Alcohol and betadine swaps Gause swabs and dry paper tissue

2 cc syringes with 25 gauge needles for reconstitution of botulinum toxin

Sterile, preservative free(?)* 0.9% saline for dilution 0.5-1ml tuberculin syringes

Frozen gel or icepacks or, EMLA® cream for anesthesia

*Some collegues use normal saline with preservatives for less painful injections without increasing the dose.

In Table 3 the equipment needed for practical preparation, dilution and injection for botulinum toxin is listed.

THERAPEUTIC USES OF BOTULINUM TOXIN

Facial muscle dyskinesias such as benign essential blepharospasms, hemifacial spasms, Meige syndrome, apraxia of eyelid opening and orbicularis myokimia, synkinetic eyelid movements are manageable with botulinum toxin injections.

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Table 4: Periocular therapeutic and cosmetic applications of botulinum toxin

Therapeutic applications of botulinum toxin in eyelids and periocular area:

•Essential blepharospasm

•Hemifacial spasm

•Meige syndrome

•Treatment of apraxia of eyelid opening

•Orbicularis myokimia

•Aberrant regeneration of 7th nerve

•Control of synkinetic eyelid movements

•Eyelid retraction

•Lower eyelid entropion

•Lacrimal gland blockage

•Pharmacologic tarsorrhaphy for corneal protection

•Treatment of dry eye

•Adjunct to facial wound healing

Cosmetic applications of botulinum toxin on eyelids and periocular area:

•Glabellar lines

•Lateral orbital lines (crawsfeet)

•Hypertrophic orbicularis oculi

•Narrow palpebral vertical aperture

•Dermatochalasis

•Browlift

•Asymmetric features of the face

•Adjunctive procedures for other antiaging methods

involuntarily contracting muscles occasionally, when the muscle to be injected is not localized accurately.

Video documentation before and after treatment is more useful than documentary photographs.

Periocular therapeutic and cosmetic applications of botulinum toxin are summarized in Table 4.

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Botulinum Toxin Use in Blepharospasm and Hemifacial Spasm

Benign essential blepharospasm is the involuntary, repetitive contractions of orbicularis oculi muscle. Depressor muscles of eyebrows as corrugator superciliaris, procerus are also involved. Reflex blepharospasm due to dry eye must not be mistakenly diagnosed as benign essential blepharospasm. Meige syndrome is a cranial dystonia with bilateral blepharospasm accompanied by dystonia in the lower face. Involountary contractions of orbicularis oris, buccinator and masseter muscles are prominant. Hemifacial spasm is characterized by unilateral repetitive contractions of facial muscles. It may result from compression of fibers of 7th nerve root. Posterior fossa tumors may be underlying this condition. Orbicularis myokimia denotes a condition in young individuals with involuntary twitches of some orbicularis oculi muscle fiber bundles. Stress and fatigue and caffeine and alcohol intake may exacerbate the frequency and severity of spasms.

The usual dose and muscles injected for blepharospasm treatment in our practice is about 5U in each of the 3 points laterally in orbicularis oculi muscle 1 cm lateral to the lateral orbital rim. Subcutaneous injections of 2U botulinum toxin A into medial to upper and lower eyelids in the orbicularis oculi preseptal fibers, especially not into the pretearsal fibers in this area, are given. The injection sites must be at least 5 mm far from lacrimal punctae to avoid lacrimal pump failure. Botulinum toxin A injections of 1-3 units into frontalis muscles centrally and 5-10 U in the corrugator supercilii muscles and 1-2U procerus muscles administered in these group of patients generally stop contractions for 4-6 months (see Fig. 1). Patients are seen in the second week post injection,

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for evaluation of the efficacy, side effects and secondary effects of the treatment. Reinjections may be done at this visit. Doses and modifications for the future injections are noted.

Patients with hemifacial spasms need botulinum toxin injections in mid face muscles, and occasionally in the lower facial muscles. Dose vary individually , being lower than those for blepharospasm. Meige syndrome is treated with higher doses where orbicularis myokimia treatment requires lower dose injections of the toxin.

Response to the treatments with botulinum toxin continues after repeated injections in majority of the cases followed up for more than 10 years.8 For patients who are not responding to botulinum toxin A botulinum toxin B may be effective in treating the spasms.9 Injecting higher doses of toxin may also stop unvoluntary contractions, that do not respond to lower doses.27

Temporary eyelid and facial ptosis, lagophthalmus and epiphora are the undesired effects of the treatment. Diplopi a may occur as a result of diffusion of toxin into extraocular muscles.

Botulinum Toxin Use in Apraxia of Eyelid Opening

Apraxia of eyelid opening is the inability to initiate to open the eyelids. It may be noted in patients with blepharospasm due to pretarsal fibers of orbicularis oculi muscle activity.

We inject 0.5-2U of toxin A at 2 sides medially and laterally 5 mm. away from the lid margin aiming the pretarsal orbicular oculi muscle.

Botulinum Toxin Use for Dysthroid and Upper Eyelid Retraction Management

In 1996 Özkan et al investigated effect of botulinum toxin in cases with dysthyroid upper eyelid retraction, which was one

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Morgensten et al have achieved decrease in eyelid aperture in 94% of the cases by administering 2,5-10 U botulinum toxin A injections transconjunctivally in 1 or 2 points of levatorMüller’s muscle complex from the upper side of the tarsus.18 Shih, Liao and Lu have also achieved similar results by injecting botulinum toxin A through skin into levator muscle.30 Upper eyelid ptosis is the most frequently seen undesired effect of such injections, and it is temporary. Olver has also reported successful results in decreasing the activity of corrugator supercilii muscles in cases with dysthyroid ophtalmopathy by injecting botulinum toxin in these muscles.16

Botulinum Toxin Use for Entropion Treatment

Botulinum toxin injection decreases the tonus of lower pretarsal and preseptal fibers of orbicularis oculi overriding , therefore correcting entropion temporarily. 1-5 U injections to the central portion of the subciliary orbicularis muscle 3-5 mm inferior to the eyelid margin in lower eyelid trets the spastic component of entropion for 4-5 months.

Christiansen et al injected botulinum toxin A on subeyelid of a 3-week old congenital entropion patient, and treated corneal ulcers of the infant without any undesired effects.31

We do not prefer to inject botulinum toxin in infants in our practice.

Botulinum Toxin Use for Lacrimal Gland Blockage

Gustatory lacrimal gland function (crocodile tear syndrome) can be controlled by 2,5-20 U botulinum toxin A injection administered in lacrimal gland, however side effects such as eyelid ptosis and dry eye symptoms might be expe- rienced.31-34

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Botulinum Toxin Use for Cornea Protection in Facial Paralysis

For cases with facial paralysis, particularly for patients for whom a surgical procedure seems to be difficult, lagophthalmus can be decreased by achieving eyelid ptosis with 2-10 U botulinum toxin A injection in levator palpebrae superioris muscle instead of tarsorrhaphy and/or gold weight implantation, so that corneal ulcers can be prevented.35

The patients who receive radiation therapy near the face are also good candidates for this application of botulinum toxin because the atrophied eyelid skin would not tolerate an eyelid implant for a long time.

We inject 5-15 U of botulinum toxin A in the levator muscle subconjunctivally 5-6 mm above the tarsus to prevent diffusion into orbicularis oculi muscle fibers and worsen the lagophthalmus in these patients.

Control of Synkinetic Eyelid Movements

Synchronic movements of eyelid retractor and protractors as well as extraocular muscles can be seen after aberrant regeneration of especially 3rd or 7th cranial nerve palsies. The muscle contraction can be seized by customized doses of botulinum toxin injections and in these muscles.

Chua et al administrated 40-120U botulinum toxin A (Dysport) injections on orbicularis oculi muscle of 5 cases in order to limit the synkinetic eyelid movements occurring after aberrant 7th nerve paralysis, and observed that synkinetic movements descreased for 3 months both objectively and subjectively in all cases. Ptosis was observed in 2 patients, but this side effect was not seen in patients treated with lower doses such as 40 U.36

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COSMETIC ADMINISTRATION OF BOTULINUM TOXIN ON EYELIDS AND PERIOCULAR AREA

Glabellar Area

Corrugator superciliaris muscle originates at the junction of the nasal and frontal bones close to the supramedial orbital rim. A transverse line drawn coronally through the middle of the eyebrow identifies the horizontal position of the bulk of the muscle. Injections between 4 and 20 U of botulinum toxin A in the belly of the muscle at one or two points decrease or erase the glabellar frown lines. Area lateral to the midpupillary line is avoided to prevent botulinum toxin induced blepharoptosis.

The procerus muscle is located vertically in the midline of the nose. The optimal injection site is the midline just caudal to the nasal root. 1-3 U is injected at one or two points to treat the horizontal lines located at the superior part of the dorsum nasi.

In Figure 3 photographs of a patient with glabellar furrows before (left) and after (right) botulinum toxin A injection. Upper and lower row photographs demonstrate the static and dynamic wrinkles before and after treatments,respectively.

Based on the multi-centered, double-blinded, randomized, placebo-controlled study conducted by Carruthers et al, 20 U botulinum toxin A injected into corrugator and procerus muscles of glabella caused the lines to disappear, and this effect achieved its peak within 30 to 60 days, and was permanent for 90 days in 50% of the patients, and for 120 days in 25% of the patients. These effects are statistically significant when compared to placebo group (p< 0.003). The most frequently seen complication was mild eyelid ptosis observed in 1-5.4% of the patients.37,38 In another study, 30 cases were administered 10 U botulinum toxin A at the