While the terms canthoplasty and canthopexy are sometimes used interchangeably, the two procedures are very different.
"Canthoplasty" refers to an operation designed to reinforce lower eyelid support by detaching the lateral canthal tendon from the orbital bone and constructing a replacement.
"Canthopexy," on the other hand, refers to a less invasive procedure designed to stabilize or reinforce the existing tendon (as well as surrounding structures) by surgical suturing without removing it from its normal attachment.
While their names may sound very similar, canthopexy and canthoplasty are often confused, as explained in the following two videos.
EVEN MORE NAMES
As if the above were not already confusing, other terms used to denote the same or similar operations include tarsal strip resuspension, lateral canthal plication, tarsal sling, lateral retinacular suspension, inferior retinacular suspension, and more.
Strengthening the tissues at the outer corner of the eyelids (lateral canthus) to better support the lower eyelid.
Lessening the chance of surgical complications most commonly associated with transcutaneous (skin incision) lower blepharoplasty.
(Note: If the anatomical terms that follow seem confusing, refer to these anatomical illustrations).
Tarsal strip resuspension (a version of canthoplasty) is described:
Scissors are placed at the junction of the outer upper and lower eyelids (the lateral commissure) and a full-thickness cut is made into the lateral canthus towards the orbital bony rim. The lower half of the lateral canthal tendon extending from the bony rim into the lower eyelid is isolated and cut free from its attachment to the bone. An incision is made on the eyelid margin a small distance (approximately 1/5 inch) from the cut tendon, and the tarsal plate closest the tendon is cleaned of all adherent skin and conjunctiva. This creates a small strip of tarsal plate tissue, a cartilage-like structure that will be used to create "a new and tighter tendon." A non-absorbable suture is used to sew this strip of tarsal plate to the periosteum (the lining of the bone) located just inside the socket's bony rim. The attachment is reinforced with dissolving sutures, and the overlying muscle and skin are closed.
There are MANY variations in surgical technique, which allows for the level of reinforcement to range from minimal to marked. For instance, rather than tightening the lateral canthal tendon, it is possible to remove a full-thickness "chunk" of lower eyelid and sew the raw edges together ("full thickness horizontal resection"). While this simplified approach may help the lower eyelid to grip the eye, it is inferior to a tarsal strip resuspension because (1) it does not "reconstruct" a new tendon, and (2) it is quite risky in individuals with prominent eyes or poor orbital rim/cheek bone support in that it may cause the eyelid to retract downward.
Less invasive variations on canthal tendon tightening (canthopexy) involve "tucking" the soft tissues just below the end of the tarsal plate by sewing them to the lining of the orbital bone. While different approaches to canthopexy vary from simple to complex, we prefer our own modification developed over years of experience. While some surgeons use canthopexy on almost every case, we apply it selectively in less than a third of our patients.
The "key" step in all of these closely related operations is the attachment of either supporting tendon, muscle, and/or tarsal plate to the tough periosteum (external lining) of nearby bone.
If the lateral canthal tendon, surrounding supporting structures (retinaculum), and/or orbicularis muscle are stretched, canthal tendon reinforcement helps to restore more normal support to the lower eyelid. Canthopexy is not, however, indicated as a "routine" measure in all lower blepharoplasties.
CARE AND RECOVERY
As noted in Section Four. In addition, swelling in the upper and lower eyelids as well as the eye (chemosis) may persist for several weeks to months due to temporary interruption of the lid's lymphatic drainage.
RISKS AND COMPLICATIONS
Canthoplasty: The anatomy of the canthus is delicate and complicated. If canthoplasty is not well performed (or sometimes even when it is expertly performed), the junction between the upper and lower eyelids may become rounded, retracted, or deformed either immediately or after several years. In the presence of a prominent eye, shallow eye socket, or inadequate bony cheek projection, canthoplasty may result in unintended downward retraction. If overdone in patients with normal or deep-set eyes, it may, on the other hand, result in a long-lasting unnatural upward slant to the eyes.
Canthopexy: By reinforcing and stabilizing the stretched supporting structures around the eye, more than just sagging skin and bulging fat are addressed. The procedure is much less invasive than canthoplasty but may still result in some of the complications noted above.
Some practitioners claim that simple one-stitch canthopexy can stabilize the lower eyelid in patients undergoing transcutaneous lower blepharoplasty in a firm enough manner to preempt this operation's proven tendency to cause lower eyelid distortion and retraction.
We believe that any such protection is minimal and fleeting at best against the strong forces created by this dated operation.