Optimal Crease Design
It is my experience that the nasally tapered crease is slightly easier to achieve surgically than the parallel crease. Most Asians who are not born with a crease have a medial canthal fold, to a varying degree. It is therefore not necessary in the design of a nasally tapered crease to excise the entire medial fold, but sufficient to reduce it and allow the crease’s infolding to merge into a much-reduced medial fold of skin.
For a patient who wants a parallel crease, a more thorough reduction of the medial canthal fold needs to be carried out: this includes skin and subcutaneous tissues such that webbing does not result, or inadequate crease formation at the medial end of the crease. Special anchoring of the medial end of the crease to retain the parallel nature of the crease may be necessary.
The term medial epicanthoplasty is often mentioned in conjunction with Asian eyelid surgery and reflects surgeons’ concern that construction of the crease alone will be inadequate. The source of the term was in connection with abnormal epicanthus inversus seen in blepharophimosis patients or those with trisomy syndromes. The surgical solutions often involved complicated V–Y-plasty or W-plasty with multiple steps in a patient with congenital abnormalities (like telecanthus) if not treated, and therefore the surgical scars might be the lesser of two evils. If true epicanthoplasty as described in those original papers for these abnormal conditions were to be performed in an otherwise normal Asian, the probable risk for visible scar would be much greater than any possible benefits gleaned, since often the small fold can be handled easily through excision of the skin fold that overlaps while closing the medial end of an Asian blepharoplasty. Most surgeons, including the present author, are aware of this and simply perform the reduction of the fold, not evoking the word ‘epicanthoplasty’ for these small steps. The few that actually perform or promote the whole procedure risk leaving their patient with a noticeable scar. Those that perform small trimming but nonetheless call the procedure ‘medial epicanthoplasty’ are using the term in a very broad sense and are probably perpetuating misinformation among patients and confusing surgeons alike.
Depth of Crease
The level to which one may attempt to control the crease depth surgically is related to whether skin is attached to tarsus, levator aponeurosis, orbicularis oculi muscle, or to subcutaneous tissues only; and to whether any permanent sutures are used in a tightly fixed fashion, or removable sutures are used. Table 10-1 shows a reasonable proposition for control of crease construction that varies from deep crease indentation to superficial levels.
|Level VIII||Closed approach (buried ligatures, compression generated crease).|
|Level VII||Subcutaneous skin–tarsus–skin (buried knots; static crease).|
|Level VI||Subcutaneous skin–levator aponeurosis–skin (if buried knots were used).|
|Level V||Inferior edge orbicularis–aponeurosis fixation sutures (buried, dissolvable).|
|Level IV||Skin–tarsus–skin (removable sutures).|
|Level III||Skin–levator aponeurosis–skin (removable, yields dynamic crease).|
|Level II||Skin–orbital septum/aponeurotic–skin (higher fail rate than Level III).|
|Level I||Skin–orbicularis oculi–skin (removable, yields shallow or no crease).|
|Level 0||Skin–skin (removable, usually does not yield crease in a person who was born without crease).|
Common Oversights in Asian Eyelid Surgery, Incisional Methods
Location for the crease placement. At the medial end of the incision, there may be only fibrous or tendinous tissues rather than levator aponeurosis. There may not be any significant levator muscle fibers to apply a suture. In this situation, the suture is applied to fibrous tissues or epitarsal tissues, the location depending on the crease shape one desires. Similarly at the lateral end of the wound closure, there may be indistinct levator aponeurosis fibers mixed with fibrous sheaths. Again the suture attachment should be to tissues that are at the level of the superior tarsal border.
Bleeding along the levator aponeurosis. We have mentioned the presence of the superior tarsal arcade, a variant of the lacrimal artery, as well as the lateral septoaponeurotic artery, all of which can cause sudden bleeding if traversed with placement of a needle near the aponeurosis (whether simply taking a small bite on its anterior surface or full-thickness traversing through the levator aponeurosis as in suture ligation methods). When this occurs, it is prudent to attempt to control the capillary oozing or hematoma formation before going further along.
Residual orbicularis along the inferior edge of the incision hinders crease formation. This can be from a less than perpendicular excision (second vector) of the skin–orbicularis flap, leaving behind orbicularis still riding over the superior tarsal border at the inferior skin edge. It should be trimmed. It can also be seen in an individual whose pretarsal orbicularis muscle is well developed or intermixed with fibro-adipose tissues. These can be reduced to allow better inward creasing from both the upper as well as the lower skin incisions.
Fat interference. Preaponeurotic fat may be encroaching along the superior tarsal border as well as the lower portion of the preaponeurotic platform. Here fat can be trimmed back through partial excision or application of bipolar cautery on the moistened fat, or repositing the fat superiorly with resetting of the tissue planes, or through a combination of all three. The key is not to be overly aggressive as one does not want complete removal of fat.
Inadvertent high anchoring of crease. This will be covered in Chapter 21 on the Faden effect.
Drifting of marking superiorly. Drift can result in a higher crease incision if the operator does not repeatedly verify the crease placement with a caliper.
Working on an individual who has latent or undiagnosed ptosis (droopy eyelid muscle); not detecting a patient with borderline levator excursion preoperatively. The crease will not fold in completely or evenly along the length of the superior tarsal border. Pre-existent ptosis must be corrected first. Those with only fair levator excursion should be advised preoperatively that there is a higher probability that their muscle may not be strong enough to fold into a good crease using a dynamic crease technique with the incisional approach. The incisional method, however, is still the better choice in creating a crease in those who needed ptosis correction first.
Individuals with a large palpebral fissure (eye opening) will often do quite well with a crease height that is low–normal; they do not need a high crease to magnify the fissure size.
Individuals with a small phimotic eye certainly do not need a crease height that is higher than average. The challenge for significantly small-eyed individuals may be that often there is some associated ptosis, and the levator excursion is weak. These latter individuals may need the inferior edge orbicularis-to-aponeurosis fixation sutures (Level V ) to be applied prior to closure, using Vicryl sutures that slowly dissolve over several weeks.
Bleeding and swelling along the orbicularis can occur quite often in individuals with well-developed orbicularis oculi. Such patients need to be individually controlled as the resultant swelling distorts the tissue plane and leads to less than accurate placement of the crease, as well as prolonging the recovery process. Excess blood can interfere with levator function in the postoperative period as well as long term if the accumulated blood swelling is very significant.