procedure that affords maximum benefit to patients with congenital ptosis. In addition, careful consideration of the patient’s preoperative amount of lagophthalmos may temper the robustness of surgical attempts to lift the eyelid, and exacerbating the patient’s inability to close his or her eyes may result in worsening of ocular surface dryness. As a general rule, we define “poor” levator function as less than 4 mm of excursion, “moderate” function as 5–7 mm, and “normal” function as at least 8 mm [1, 2].

Preoperative considerations necessitate a careful informed consent process with the patient, the patient’s family, and – where appropriate – with the patient’s pediatrician or ancillary physicians who may care for the patient. Essentially, the limitations inherent to ptosis repair should be reviewed in detail. All parties involved should be intimately aware of the preoperative findings and their significance, and any systemic or ophthalmic syndromes that have been unearthed in the preoperative phase should be discussed in depth. Furthermore, because preoperative ocular surface disease and lagophthalmos necessitate a conservative surgical approach, the possibility of undercorrection and postoperative dry eye should be addressed. Contour defects merit specific consideration, as they may not be completely repaired in the surgical process.

Surgical Repair

Surgical interventions for repair of congenital ptosis fall into three categories. Patients with fair or good levator function are candidates for levator resection surgery. In cases of 1–2 mm of ptosis, a Müllerectomy can be considered in patients who respond favorably to provocative testing with phenylephrine eye drops. Finally, patients who have poor levator function and significant ptosis should be treated with frontalis suspension techniques. In order to provide general guidelines for the selection of a specific surgical technique, the severity of ptosis is juxtaposed against the amount of levator function. Please see Fig. 8.1 for a potential management strategy. In light of

more extensive details regarding the technical aspects of these procedures that can be found elsewhere in this book, our discussion of the various surgeries that can be employed in congenital ptosis centers on their clinical utility and application.

Müllerectomy

The usefulness of posterior ptosis repair is somewhat limited in cases of congenital ptosis. Specifically, Müllerectomy procedures are best employed in cases of minimal ptosis (1–2 mm) with good levator function, and these patients represent a very small portion of cases of congenital ptosis. However, when appropriate, patients can be tested for candidacy with provocative testing with phenylephrine drops. After instillation of such drops, Müller’s muscle is selectively stimulated, and the ptosis may reverse. As such, the patient may undergo repair via Müllerectomy, in which Müller’s muscle is resected in a transconjunctival fashion, thereby increasing its strength [4].

Levator Resection

Assuming that it is employed appropriately, levator resection surgery is highly effective in cases of congenital ptosis. Essentially, this surgery advances and plicates the levator muscle, thus increasing its effect. Nonetheless, the relationship between the amount of levator advancement and eyelid elevation is nonlinear; as such, rough guidelines have previously been developed to determine the amount of levator to resect during surgery, but these strategies should be adapted to each surgeon’s experience.

Historically, Beard developed an algorithm in which the surgeon preoperatively determines the amount of levator for intraoperative resection. Alternatively, Burke advocated for intraoperative adjustment of the resection, based on the upper marginal reflex distance. In either case, the