Abstract
Purpose: :
To evaluate orbicularis oculi muscles of blepharospasm patients and if there are alterations induced by eyelid injections of botulinum toxin type A (BTX-A).
Methods: :
The orbicularis oculi muscles were obtained from 14 patients undergoing blepharoplasty or myectomy (10 with blepharospam and 4 healthy, who underwent surgery for cosmetic purpose). Among those with blepharospasm, 3 had no previous treatment and 7 had received BTX-A injections 30 to 210 days before the surgical procedure. Fragments of skin and eyelid muscles were frozen in liquid nitrogen and were prepared by routine histological and histochemical staining, including hematoxilin eosin (HE), modified Gomori, periodic acid Schiff, NADH, cytocrome C oxidase, acid and alkaline phosphatases and ATPases 4.3 and 9.4.
Results: :
A marked morphological difference in muscle fibers was observed between control and patient groups. While morphology was preserved in normal controls, all patients with blepharospasm presented basophilic intracytoplasmic alteration of muscle fibers, strongly suggestive of mitochondrial proliferation. All patients submitted to BTX-A injection previous to surgery presented marked positivity to acid phosphatase.
Conclusions: :
Blepharospasm was associated to morphologic alteration in eyelid muscles, independent to BTX-A treatment.