Since the eyelid musculature is extremely vascular, the patient must avoid anticoagulative medications prior to surgery. These medications include acetylsalicylic acid (aspirin), aspirin-containing products such as Alka-Seltzer, nonsteroidal anti-inflammatory medications such as ibuprofen (Motrin, Advil) and naproxen (Aleve), warfarin, heparin, low-molecular weight heparin, and other platelet inhibitors such as clopidogrel (Plavix). Nonprescription medications such as high-dose vitamin E, ginko biloba, and ginseng have also been reported to have anticoagulative properties. Uncontrolled hypertension can also result in excessive bleeding; blood pressure control is mandatory both during the surgical procedure and postoperatively as well.

Most essential blepharospasm patients that undergo surgical eyelid myectomy have already received treatment with serial injections of botulinum toxin A. Since there can be significant postoperative edema associated with the myectomy procedure, botulinum toxin A injection in the perioperative period can result in unexpected spreading of the medication to undesired locations such as the midface or lower face. In planning for an eyelid myectomy, regardless if it is upper eyelid or lower eyelid or both, it is best to avoid botulinum toxin A injections for at least 2 weeks prior and 2 weeks after the surgery.

SURGICAL TECHNIQUE

Skin marking

When performing the upper eyelid myectomy, an eyelid crease incision similar to that used in upper eyelid blepharoplasty may be used. As most patients with long-standing essential blepharospasm will also have some degree of dermatochalasis, a conservative skin excision can also be marked; however, the surgeon must be judicious in skin removal as aggressive excision may exacerbate postoperative lid closure. When performing the lower eyelid myectomy, a subciliary incision should be used and no skin excision should be planned to avoid the risk of postoperative lower eyelid retraction.

Regardless of whether the patient is to have general anesthesia or local anesthesia, use of infiltrative local anesthetic with epinephrine is necessary to provide adequate hemostasis during the procedure. Lidocaine 2% with 1:100,000 dilution of epinephrine is infiltrated in the subdermal plane using a 27-gauge needle for the entire extent of the myectomy. The injection should be performed several minutes prior to surgery to achieve adequate vasoconstriction prior to the incision. The patient is then prepared and draped in a manner similar to that of a blepharoplasty procedure.

Skin incision

The skin incision over the previously placed markings is performed with a No. 15 Bard-Parker blade. This incision is made with a technique identical to what one would use for a standard blepharoplasty procedure. Excision of the skin and orbicularis muscle corresponding to the area previously demarcated is then performed using Stevens scissors. It is preferable to leave the underlying orbital septum intact at this time. After excising the demarcated skin and muscle flap, the orbital septum should be left intact to prevent prolapse of preaponeurotic fat and minimize the risk of inadvertent injury to the levator aponeurosis.

The eyelid protractor myectomy involves extirpation of the pretarsal, preseptal, and a portion of the orbital orbicularis oculi muscle. The corrugator supercilii muscle is also a strong protractor and should be excised during the procedure as well. In most patients with essential blepharospasm, the upper eyelid myectomy is adequate to provide significant relief of their eyelid spasms. In severe cases where eyelid spasms persist after the upper eyelid myectomy, a lower eyelid myectomy of the pretarsal and preseptal orbicularis oculi muscle should then be performed.

Figure 36-1. Using two rake retractors, the skin superior to the incision should be placed on tension and Stevens scissors can then be used to create a dissection plane between the preseptal orbicularis oculi muscle and the overlying dermis. The subdermal dissection plane is extended superiorly above the orbital rim and eyebrows to allow extirpation of a portion of the orbital orbicularis oculi.