[Use of botulinum toxin in ophthalmology]

Botulin toxin A was introduced as a treatment in ophthalmology by Dr. Scott of San Francisco. One important application is in cases of blepharospasm, where the toxin is injected into the lateral parts of the lower and upper lid and, if necessary, over the eyebrows in a single dose of 1-2 nanograms, preferably using a needle under electromyographic control. The effect on the blepharospasm is visible after a few days and lasts for several months. The procedure can be repeated several times. The second application is in cases of strabismus. In paralytic strabismus, contracture of the antagonist of the paralyzed muscle can be weakened by local injection of botulin toxin with a coaxial electrode under electromyographic control. Good results were observed in cases of eye muscle disorders in endocrine ophthalmopathy. In concomitant strabismus (exotropia or esotropia) administration of botulin toxin is also possible although a certain paresis of the injected muscle has to be taken into account. The doses for strabismus vary between 1/2 and 2 nanograms of the toxin. The administration of botulin toxin either in blepharospasm or strabismus has no systemic side effects and is a safe procedure if performed under careful electromyographic control. First personal experiences in the treatment both of blepharospasmus as well paralytic strabismus and concomitant strabismus are reported.