Traditional canthoplasty techniques involve separating the upper and lower limb of the canthal tendon and tightening the lower tarsus to the orbital rim, Dr. Goldberg says. As such, "The incision between the upper and lower eyelid can leave a red scar. It also disassociates the upper and lower eyelid, creating the possibility of web formation and length disparity in the lateral canthal tendon," he says.
Accordingly, Dr. Goldberg says he and his colleagues prefer a technique that preserves the unity of the upper and lower canthal tendon limb and avoids a horizontal incision in the conjunctiva and interpalpebral fissure. More specifically, he says that patients with positive snap test and lower lid laxity that's not severe are good candidates for small-incision closed lateral canthoplasty.PROCEDURE DETAILS The procedure begins with a small horizontal incision in the lateral crease line of the upper eyelid. "Blunt dissection deep to the orbicularis allows access to the lateral orbital rim," Dr. Goldberg says. Once there, pressing the scissor against the lateral orbital rim and pushing the scissor into the infralateral orbit releases the canthal tendon. "The cut edge of the canthal tendon is equivalent to a tarsal strip. In fact, using the scissor tips, we can trim the cut edge of the tendon to achieve some additional horizontal shortening."
Next, Dr. Goldberg reduces the infralateral fat pad. "This lateral fat pad can be accessed through the upper lid crease incision. In many ways, this approach is more straightforward than the transconjunctival inferior eyelid approach." In particular, he says that gentle, blunt dissection into the infralateral orbit reveals the lateral orbital fat pad. Surgeons can "tease" it out of the orbit with gentle dissection and pressure on the globe provided by a surgical assistant. "We've found that the infralateral fat pad can be readily accessed and sculpted through this lateral upper eyelid crease incision," he says.
Dr. Goldberg then passes a PDS (polydioxanone, Ethicon) or Maxon (polyglyconate monofilament, Covidien) suture through the gray line and lateral canthal tendon. "By going through the gray line, we can consistently exit through the cut edge of the lateral canthal tendon," he says. "The needle tip then engages the arcus marginalis of the orbital rim deep in the lateral wall." His technique at this point involves rolling the needle through the periosteum to engage a hearty bite of periosteum deep inside the orbit at a level roughly 2 mm to 3 mm above the medial canthal tendon.
"I pass the second arm of the double-armed suture through the same hole and through the tarsal strip, but at a slightly higher level, to create a loop within the tarsus," he says. Again, the needle tip engages the arcus marginalis periosteum deep to the lateral orbital rim, and he brings the needle through the periosteum to engage it in the appropriate vertical position.
Dr. Goldberg ties the suture under appropriate tension, taking care to avoid overtightening it, so that the eyelid maintains its normal, physiological tight tone. "We can achieve additional tightening and support with an orbicularis bite," which also can be taken percutaneously, with a loop through the orbicularis that is externalized through the skin, he says. "By sawing back the suture, as with a Gigli saw, we reduce the dermal attachment and leave the deep orbicularis attachments, which provide a gentle vector for supporting the orbicularis sling."
Next, Dr. Goldberg says that one can suture the orbicularis sling down to the periosteum at the zygoma with a mattress suture taken through the zygomatic periosteum in a lateral to medial direction. Passing this suture back through in a medial to lateral direction provides a deep fixation point for the orbicularis sling, fixating it to the zygomatic periosteum for vertical support of the anterior limb of the lateral canthal tendon.
Finally, Dr. Goldberg closes the small incision with absorbable suture. "This surgical technique provides horizontal shortening, which is very similar to that accomplished with an open canthoplasty," he says. "In fact, the anatomic approximation of the cut edge of the canthal tendon and tarsus with the lateral orbital periosteum is essentially equivalent." The only differences with the small-incision procedure are that the surgery is faster, the small eyelid crease incision heals more easily, "and there is no significant risk of creating a web or scar in the interpalpebral area," he says.
To perform the same procedure through an open upper blepharoplasty incision, "Again, place the scissor tip along the lateral rim, disinserting the upper and lower limb of the lateral canthal tendon," he says. "The lateral inferior orbital fat pad is easily accessed through this upper eyelid crease incision, and sculpted as appropriate, depending on the patient's needs."
As in the small-incision canthoplasty, one should pass the double-armed suture through the gray line and through the lateral canthal tendon, then anchor it with a deep bite into the lateral orbital periosteum designed to achieve appropriate posterior placement of the canthal vector. "The second arm of the double-armed suture passes through the same needle hole, through the lateral tarsal strip in a slightly different position," Dr. Goldberg says.