Congenital Ptosis
Frontalis Sling
This is the most common surgery performed for congenital ptosis and is especially useful in instances where the levator function is very poor. In this procedure, the eyelid is coupled to the frontalis muscle using either a fascial sling or a sling made of a synthetic material (discussed below). By recruiting the frontalis muscle to raise the eyelids, this procedure relieves the dysfunctional levator from contributing to eyelid elevation.
There are a number of materials that can be used to sling the frontalis to the eyelid; each has its own indications, advantages and disadvantages.
Sling materials:
Fascia lata: Fascia lata, the deep fascia of the thigh, is one of the most commonly used materials for frontalis sling. Fascia lata can either be harvested from the patient (autogenous fascia lata) or be provided by a tissue bank (allogenic fascia lata)
Autogenous: Autogenous fascia lata is thought to be the gold standard material for a frontalis sling. It has excellent tensile strength and, as a living tissue, biointegrates into the eyelid/forehead environment in a way that makes rejection rare and absorption of the material/recurrence of ptosis equally unlikely. One disadvantage of autogenous fascia lata is the creation of a second donor site and the infectious risks therein. Also, it is generally difficult to harvest enough fascia from a child under the age of three, so autogenous fascia is not an option for infants.
Allogeneic: Allogeneic fascia has all of the advantages of autogenous fascia and can be used in infants under the age of three. A second donor site is not required in these cases. There are the theoretical risks of rejection of the sling material and the transmission of infection from the donor to recipient, but generally speaking these slings are well tolerated.
Supramid:
Supramid Extra, a 4-0 polyfilament cable-type ophthalmic suture, is a synthetic alternative to fascia lata. Its advantage is that it does not require a donor site and can be used in children of any age. Supramid has, however, been associated with recurrences of ptosis and is not thought to be a reliable permanent solution for congenital ptosis (Katowitz 1979). Scanning electron micrographs of Supramid used in ptosis cases that recurred show that the material undergoes a morphologic degradation by hydrolysis, supporting its use as a temporary measure only (Kook 2004). Supramid is generally reserved for infants/children who need their ptosis addressed quickly (because of amblyopia, for example) but who will later undergo a more permanent sling.
Silicone:
Silicone is another synthetic alternative to fascia that also does not require a donor site and can be used in patients of any age. Unlike Supramid, silicone is not associated with frequent recurrence of ptosis and is often used as a permanent solution for congenital ptosis (Lee 2009). The other advantage is that the material is elastic and can be adjusted, both intraoperatively and post-operatively, if the eyelid height needs to be altered over time.
