Congenital Ptosis
Levator Resection
The levator resection surgery is an intervention used in those patients who have some amount of levator function. Unlike a levator aponeurosis advancement in adults, the amount of advancement cannot be adjusted intraoperatively (assuming the patient is a child and the procedure is being done under general anesthesia); the amount of resection is decided preoperatively. Another difference between adult and pediatric levator resections is that children with congenital ptosis generally require a much larger levator advancement. Most levator resections in children require a dissection superior to Whitnall's ligament except in the mildest of cases, but this is rarely necessary when correcting adult involutional ptosis.
There are numerous ways to estimate the amount of levator resection necessary to correct congenital ptosis. The two methods that are most commonly cited and used are those explained by Beard and Berke in their respective reports of congenital ptosis repair.
The method explained by Beard incorporates both eyelid excursion and amount of ptosis to estimate the amount of levator to be resected. Please see Table 1 for the specific figures for this estimation.
| Amount of Ptosis | Upper eyelid excursion | Amount of Resection |
|---|---|---|
| 0-5 mm (poor) | 22-27 mm | |
| 2 mm (mild) | 6-11 mm (fair) | 16-21 mm |
| 12 or more (good) | 10-15 mm | |
| 0-5 mm (poor) | Maximum (30 mm) | |
| 3 mm (moderate) | 6-11 mm (fair) | 22-27 mm |
| 12 or more (good) | 16-21 mm | |
| 0-5 mm (poor) | Maximum (30 mm) | |
| 4 mm or more (severe) | 6-11 mm (fair) | 25-30 mm |
| 12 or more (good) | 25-30 mm |
The method described by Berke uses upper eyelid excursion not to determine the amount of levator that needs to be resected, but rather to determine the intraoperative eyelid height at the end of the surgery. The idea behind this approach is that an eyelid with good excursion will rise from its final intraoperative height, and an eyelid with poor excursion may drop from its final intraoperative position. Table 2 details this approach:
| Upper eyelid excursion | Superior corneal coverage by upper eyelid |
|---|---|
| 0-5 mm (poor) | 0 mm (lid margin at superior limbus) |
| 6-11 (fair) | 2 mm |
| 12 or more (good) | 4 mm |
These two tables represent not concrete rules, but rather guidelines to assist in surgical planning for congenital ptosis. Most oculoplastic surgeons probably use some combination of these two methods and adjust their operative approach on a case-by-case basis.
