Optimal Closure and Management of Wound Healing

Dynamic Interaction of the Pretarsal Platform and the Preaponeurotic Zone

One can divide the upper eyelid into three zones: the eyelid crease (which acts as the junctional zone or the rotating nano-balls, see Chapter 23 ), the pretarsal zone below it and the preseptal zone above it ( Figure 12-2 ). The objective of the surgeon in forming or enhancing an upper eyelid crease should be:

• 1.

  To facilitate the inward folding of the crease (through the nano-balls) by reducing the soft tissue overlay through limited debulking of redundant preaponeurotic soft tissue, which may be hindering the infolding, or by tightening this pivoting zone through suture ligation (which is less effective by comparison, and more prone to regression). By providing a clear demarcation zone, one achieves a good pivot or nano-ball junction.

• 2.

  The pretarsal area (lower zone) can be made firmer through (a) excision of some orbicularis oculi muscle along the inferior incisional skin edge, or (b) suture ligation, through conjunctiva to subcutaneous plane buried sutures, or through external skin to levator aponeurosis buried sutures.

• 3.

  The fullness of the preseptal area (upper zone) should be preserved by conserving and repositioning most of its preaponeurotic fat superiorly into its sulcus or the upper quadrant of the orbit. There should be no excessive skin removal to avoid foreshortening of the anterior lamella of this upper zone.

These three focal points serve to create an opportunity for the firm pretarsal platform and tarsus (the tarsal–crease unit) to vector upwards and slide under the preseptal soft tissue zone above it, without much effort or encountering any tissue resistance over the crease. The preseptal zone bellows freely over the pretarsal zone, with a crease formed in between.

Conceptually, the crease is thought to form above the highest point of insertion of the distal terminations of the levator aponeurosis through the orbicularis oculi's intermuscular septa, as well as skin along the crease line. That is not to say that there is absolutely zero presence of terminal fibers of the levator aponeurosis above the dominant crease. My trapezoidal debulking approach ( Chapter 11 ) allows a skin–aponeurosis–skin closure, with a 1–2 mm zone where the transected orbicularis (along the upper beveled skin–muscle wound plane) may become adherent to the aponeurosis just above the superior tarsal border, thereby reforming the ‘limiting boundary’ previously described as the posterior reflection of the orbital septum on to the levator aponeurosis sheath, and acting as an inferior limit to the repositioned preaponeurotic fat. The surgically created crease simply forms directly above this zone. Therefore, although the lid crease wound is formed along the superior tarsal border, by taking skin to aponeurosis to skin, the upper lid crease thus formed may lie just above this junction. Another way to conceptualize this is that the aponeurosis is attached to both upper and lower wound skin edges, with the crease thus created lying above it.

Several factors in the upper/preseptal zone can lead to poor infolding of the crease. If fat excision in the preaponeurotic space was excessive, there is now direct physical contact between the aponeurosis and the orbicularis, as the septum has been opened. There is then an attenuation of the preaponeurotic space, which can predispose to cicatrix formation and an increase in rigidity of this zone. If there was inadvertent tissue handling, injury, or above-normal hemorrhaging, there can be increased scarring and consequent rigidity. If there was excessive skin excision in this upper zone, there is a greater probability that the pretarsal–eyelid crease unit will be unable to form a crease by vectoring upward under these scarred and therefore tighter preseptal tissues (of skin, orbicularis, septum and possibly attenuated fibrosed fat tissues). These seemingly benign factors can combine to substantially hinder crease formation.

In Caucasians born with a natural crease, the relatively higher point of fusion of the orbital septum on to the levator aponeurosis limits the preaponeurotic fat to above this fusion point. The crease may have formed from distal terminations of the aponeurosis in towards the inferior orbicularis muscle septa, actual subcutaneous attachment or ‘extensions’ from the levator, and inferior limitation of fat through a postero-upward reflection of the posterior layer of the orbital septum on to the levator aponeurosis (this latter scenario may simply yield a prominent supratarsal sulcus in Occidentals who have never had eyelid surgery). This, combined with a softer and thin-skinned preseptal zone, allows the firm tarsal complex to easily vector upward against it to form a crease.

In Asians with a single eyelid, this attempt to form a crease is more difficult for a variety of reasons: the pretarsal soft tissue (skin and boggy orbicularis) is often softer and more redundant; the septum fuses on to the levator aponeurosis and tarsus at a lower point; preaponeu­rotic fat is present at a lower level; the preseptal zone may have significant fullness and is often positioned more forward in the orbit (Asians have comparatively less deep-set eyes, owing to a less prominent forward extension of the superior orbital rim). These factors are more likely to yield a single lid without a crease.

Following an Asian eyelid crease enhancement procedure, with preservation of fat in the preaponeurotic middle space, coupled with reduction of the pretarsal inferior edge soft tissue, as well as clearance along the superior tarsal border and controlled debulking of the preaponeurotic platform, it will be easier for the crease to indent up. The levator's dynamic pull (up-vector) is most effective when the muscle can glide up against a cushion of non-adherent preaponeurotic fat (middle space) as well as overlying anterior skin–orbicularis. In essence, the tarsal plate and skin are allowed to invaginate against a multilayered soft tissue complex (preaponeurotic fat, septum, orbicularis, subcutaneous fat and skin). It will be more difficult if the preaponeurotic space is obliterated through ablation of its fat; cicatrization forms between the anterior layer of skin–orbicularis–orbital septum and the posterior layer of levator–Müller's muscle–conjunctiva through tissue damage or excessive hemorrhage and subsequent hemosiderin deposition. The resultant rigid multilayered tissue complex presents a far greater mass of tissue, as well as a challenge for the tarsal plate to indent against to form a crease. We may see this clinically as a firm band of skin/muscle/anterior lamella in the preseptal region, accompanied by a static-looking crease.

On occasion, postoperative swelling can mask an otherwise well-formed crease; and when the swelling resolves, the tarsal plate vectors up well against the preseptal soft tissue and a crease then appears appropriately.

The suture ligation methods create a crease by tightening the soft tissue overlying the superior tarsal border, creating a firmer constriction between the subcutaneous skin and the levator aponeurosis (through either an anterior skin or a posterior conjunctival approach). It allows an increased force-gradient where the tarsal plate uplifts in and under the preseptal soft tissues. With no removal of redundant soft tissue, it is effective in the short term (perhaps up to 5 years). However, with aging and a gradual increase in soft tissue redundancy, the crease thus created may become shielded from view or shallow out with time (fading) owing to the unavoidable shredding forces of the buried sutures used in these methods. (The ligatures' effect may diminish in time, not from the dissolution, loosening, or breaking apart of the sutures, but more from the ligature working and cutting through the tissue layers which it was meant to tie together.)

The application of the crease-forming sutures depends on accurate placement along the superior tarsal border's levator aponeurotic fibers. The appropriate number of these interrupted sutures is applied to form a uniform continuous crease invagination. Upon tying of these sutures, we should avoid excess tension or strangulation effect on the tissues. The running stitch after this merely approximates the skin edges together.

The choice of suture material depends on the preference of the surgeon, balancing potential wound reaction, discomfort or comfort for the patient, and desired healing that enhances the crease construction. It determines the number of days for which the sutures are left in place before removal, again balancing success rate for crease formation versus skin reaction.

Postoperative wound cleaning and dressing is standard. This involves the use of antibiotic and anti-inflammatory (steroid) combination ophthalmic ointment.

In patients with oily skin one may elect to add the prophylactic use of oral antibiotics, and anti-comedogenic skin preparations. There are also a wide range of dietary recommendations that can be given for Asian patients according to their ethnic food cultures, based on the traditional Chinese medical belief system.

Other factors that may affect healing first and foremost will include the patient's own tissues (genotype and phenotype), exposure to external environment (sun exposure, local hygiene), past history of sun damage or wound stress, dermatological conditions like eczema and psoriasis, and how recently any surgery was performed in the deeper and superficial layers of the eyelid.