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Botulinum toxin in Ophthalmic Practice Dr Sunayana Bhat Consultant Paediatric ophthalmology , Strabismus and Neuro ophthalmology Vasan eye care , Mangalore Ph : 9611102754chanyn9@gmail.com
Botulinum toxin injections are the fastest-growing cosmetic procedure all over the world
• Neurotoxin : Bacterium “Clostridium botulinum” • 'botulus' sausage German physician who described the poisoning after the ingestion of sausage.
• Mechanism of action • Activity and dosing• Clinically available forms • Uses • Complications
Mechanism of action • Heavy chain of 100 kDa • Light chain of 50 kDa 150 kDa core type A molecule
Mechanism of action
ENDOCYTOSIS
SUBSTRATE MODIFICATION
Mechanism of action • Differ in SNARE protein / cleavage site A,B,C,D,E,F
PROCESS OF FUNCTIONAL RECOVERY
Sprouting of nerve fibers from the terminal axons Extra junctional Ach receptors
Activity and Dosing• 1 unit : LD50 female swiss webster mice , intra peritoneal
injection • 1 unit : 0.05 ng of toxin
• Stored dry • Reconstitution with saline 5-10 u : 0.1 ml
Commercial Preparations
Benign Essential Blepharospasm• Functional blindness : Episodic Spasms • Effective in 75%• 2.5 u each site …
• Subcutaneous • Sites :
Stabismus : Muscle Inj • Post paralytic ( prevent contractures )• With transpositions : for horizontals • Dysthyroid orbitopathy • Surgical surprises !• Infantile ET ??? Buying time
Nystagmus / Oscillopsia
The "ideal" patient for retrobulbar Botox -restricted movement -oscillopsia, -willing to use only one eye.
Chronic Dry Eyes Medial orbicularis muscle : inj
failed lacrimal pump
Subjective improvement of symptoms in 70% of cases
Post Peripheral Facial Nerve Synkinesis • Facial deformity• Drooling• Twitching / muscle spasms
Tics,Tremors and Myokymia• Spontaneous discharges• Known to resolve spontaneously
2.5 u
Elevated IOP due to Restrictive Myopathy
Corneal Protective Ptosis
Direct infiltration of levator muscle
Headache Syndromes
50 – 100 u
Eyelid diseases • Retraction grave’s disease
• Spastic Entropion Pre tarsal orbicularis overides- Ocular sx- Irritation
Compressive Optic Neuropathy • Enlarged muscles : crowding
• Reduced contraction • Reduced muscle bulk
Hyperhydrosis Lacrimal Hypersecretion syndromes • 1% population • Face , axilla , palms
• Frey syndrome : gustatory sweating
• Gustatory epiphora 2.5 U palpebral lobe of lacrimal gland8 mm of schirmer value reduction
Aesthetic uses • Forehead furrows• Glabellar lines • Lateral rhytides ( crows feet )• Brow lift • Perioral rhytides ( smokers lines )• Mesolabial folds (marionette lines )• Platysmal bands
ALL
IS
WELL………….
Complications • Ptosis - always transient• Induced deviations - usually transient• Diplopia - transient• Dilated pupil - rare• Reduced accommodation - rare• Scleral perforation* - rare - potentially serious• Lip droop - very bothersome; may be persistent
Future Trends • Antibody development ….
• Complication : anti globulin within 4 hrs
• Bioterrorism ……VACCINES ????.....
Thank u
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