This very advanced chapter deals with the author’s current views regarding the practice of applying buried sutures to create or magnify an eyelid crease. An in-depth analysis of its adverse hindering effects is accompanied by two demonstration video clips.
It was not long ago that the proper way for plastic surgeons and eye surgeons to perform traditional upper blepharoplasty was to take off as much skin and fat as possible, and to apply a high crease fixation. The result is a sculpted look, with a prominent and showy pretarsal segment of skin along the lid margin, and a concave sulcus that stretches back towards the apex of the orbit. This look eventually lost favor when it became evident that there is an age-related spontaneous reduction of fat volume in the upper portion of the orbit (whether due to shrinkage or posteroinferior movement of fat). An often unnoticed side effect that ophthalmologists come across from these techniques, which utilized high fixation of crease on the lid, is that there seems to be a greater incidence of consecutive ptosis (droopy upper eyelid follows high fixation above the distal insertion of the levator aponeurosis). Therefore, empirically:
H i g h a n c h o r i n g o f c r e a s e ( w o u n d c l o s u r e ) → m a y l e a d t o c o n s e c u t i v e p t o s i s .
Anchoring a crease at a point more proximal (closer to orbital apex origin) than its natural likely insertional point is akin to decreasing the contractile strength as well as the effective contractile length of levator (along its 40 mm course from its origin at the orbital apex to its insertion at the lid crease). Is it the strength or length that is affected? Or both?
To understand this, ophthalmologists and house officers may recall learning how to do a posterior fixation suture (Faden procedure ) when trying to weaken the effective pull of the medial rectus muscle in strabismus surgery, especially in large angle congenital esotropia, where children are born with severely crossed eyes. The placement of a posterior fixation suture is often done in conjunction with a recession of the particular extraocular muscle’s insertion. The idea is that by moving back from the insertion of the medial rectus muscle and placing an intrascleral non-penetrating lamellar stitch there (e.g. 3–5 mm posteriorly), one can further magnify the weakening effect of surgical recession of the pull of the extraocular muscle, which is the goal of repair in esotropia. Furthermore, placement of a Faden posterior fixation suture alone (that is, placing a suture proximal to its insertion on the eyeball) without recessing the tendinous insertion of the medial rectus can provide a recessional effect. ( Faden means a piece of thread in German; here it means suture.)
Traditional theories have stated that this is due to a loss of effective arc rotation of the globe when the contact point is moved backward (proximally) resulting in a decrease in rotational efficiency, or that one has rendered the muscle’s rotation less effective through a decrease in contractile length, or through a tethering effect when a segment of the muscle closer to the mid-belly of it is attached to the globe.
Oculoplastic surgeons understand that when the levator is deliberately recessed as a form of treatment in patients with retracted upper lids, there is lessened levator excursion and less crease indentation owing to disinsertion of the levator aponeurosis. This recession of upper lid pull can be enhanced with the interposition of spacer graft. The lessened levator excursion leads to a secondary ptosis, and is often protective of an over-exposed cornea.
Clark et al., through several published papers, have demonstrated that there may be additional factors at play, including the rotational pulley effect where orbital tissues can be tethered when the medial rectus is incorporated towards the anterior muscle–orbital sheath (which invariably consists of fat and fibro-connective tissue septae) at its original insertion on the globe using a buried stitch, and duplicating the effect of Faden posterior fixation without having to apply any intrascleral stitch posterior to the medial rectus insertion. Clark attributes the majority of the dampening effect of Faden as being due to a change in the surrounding orbital pulley rather than a loss of effective arc contact of the rectus muscle on the globe. The stitch initiates the change, while the change occurs in the tissues thus incorporated into the insertional end of the medial rectus (at its superior and inferior poles).
This is interesting because it shows that at least over the insertional end of a muscle like the medial rectus, posterior fixation suturing underneath it towards the sclera of the eye (which I will refer to as ‘endo-Faden’, or fixated to the inner or under layer), as well as suturing that same location (pole) of the medial rectus towards its surrounding soft tissues (orbital sheath and pulley mechanism, which I will refer to it as ‘ecto-Faden’, fixated to adjacent or overlying layer ), can each independently result in a decrease in net function of that muscle along its primary axis of action. Therefore:
F a d e n ( e n d o – o r e c t o – ) → c a n l e a d t o w e a k e n i n g o f p u l l o f m e d i a l r e c t u s .
This coincides nicely with the observation of secondary ptosis that we see in patients (whether Caucasians or Asians) who have had their crease placed in a higher than normal physiologic position, as well in those who underwent permanently buried sutures methods using non-dissolvable sutures that encircled the levator–Müller’s muscle complex through a high reach posteriorly. (‘High reach’ means further above the superior tarsal border). This is likely from a decrease in net function of the levator muscle, when the levator aponeurosis is attached (tethered to adjacent tissues) at a point more proximal (higher) than its usual termination along the superior tarsal border and adjacent skin.
The net decrease in levator function can be a combined effect of restrictive length of contraction with a higher crease (by placing stitching closer to the levator muscle mass, and closer towards its origin from the orbital apex is likely to incrementally affect the optimal length-tension point on the contractility curve of the muscle), as well as increasing the load (by adding tissue impedance) to its ability to lift the eyelid. This latter scenario comes from the portion of levator and aponeurosis bounded by the high fixation or encircling suture loops (in buried suture methods) now having to carry a greater load of tissues (lid margin, pretarsal segment of skin/orbicularis, tarsal plate and preseptal skin/orbicularis and aponeurosis below and bounded by this higher anchor). Fixating (or associating) additional anterior lamella tissues for the levator aponeurosis and Müller’s muscle (which are the posterior lamella of eyelid) to bear is akin to the medial rectus being fixated to adjacent orbital tissues near its pole of insertion (Clark et al. ); the latter re-creates the deadening effect of posterior fixation (Faden technique) where medial rectus is stitched through partial thickness to the underlying sclera at a location just posterior to its original insertion. The high placement of buried sutures both traps additional tissues as well as creates a high ‘Faden effect’ since it tethers the levator anteriorly at a point higher than its original insertion. The levator being tethered to skin–orbicularis muscle anteriorly is similar to medial rectus being intentionally tethered to orbital tissues or underlying sclera. The patient often complains of heaviness of the lids. Eventually we see the levator wearing out and the lid may develop ptosis.
We can conceptually think of a high-anchored crease as having an ‘ecto-Faden’, since the blepharoplasty closure stitch is often placed anteriorly, within the levator muscle’s distal portion.
We can see how a crease incision that is placed higher than normal, even if only a millimeter too high, can unintentionally lead to a restriction on the uplift.
H i g h f i x a t i o n o f c r e a s e s u t u r e s o n l e v a t o r → F a d e n – l i k e e f f e c t ( i n e x t e r n a l i n c i s i o n a l b l e p h a r o p l a s t y ) .