Botulinum toxin therapy of eye muscle disorders. Safety and effectiveness. American Academy of Ophthalmology.

BTX injection has been used for 11 years by 292 ophthalmologists in 8,854 patients aged three months to 90 years in a variety of eye muscle and eyelid disorders. No systemic toxic reaction has occurred, local complications are few, and visual loss has not occurred in any case. In blepharospasm and hemifacial spasm BTX appears to fill an important need, since no other drug is reliably effective and since surgical interventions have substantial side effects. Strabismus cases with active uveitis, hypotony, previous detachment surgery, active thyroid eye disease, and recent paralytic strabismus are often poor candidates for surgical intervention. Some patients in each of these categories were treated effectively and safely by BTX injection. Surgery is clearly the preferred treatment modality in large angle deviations, in chronic paralytic strabismus, in cases where diplopia for a month or two from injection would incapacitate the patient, in nystagmus, in oblique muscle disorders and A-V patterns, where muscles have been misplaced and where restrictions to alignment have been created by disease or prior surgery. Side by side comparisons of surgery and injection in congenital esotropia and in concomitant strabismus of 50 PD or less should result in further clarification of treatment choices as to effectiveness, side effects and cost. BTX is presently available only to clinical investigators using the drug under research protocols.