Intraoperative Significance of Lower Eyelid Positions in Levator Advancement to Prevent Overcorrection.

PURPOSE The purpose of this study was to investigate changes in the position of the upper and lower eyelids before and immediately after surgery in patients that underwent ptosis surgery. METHODS The authors retrospectively reviewed the clinical records of patients diagnosed with congenital or aponeurotic ptosis and that were treated with levator advancement with local anesthesia. The marginal reflex distance 1 (MRD1), marginal reflex distance 2 (MRD2), and palpebral fissure height (PFH) were measured using clinical photographs. RESULT The preoperative mean MRD1, MRD2, and PFH were 0.27 ± 1.34 mm, 5.73 ± 1.13 mm, and 5.99 ± 1.94 mm, respectively. The postoperative mean MRD1, MRD2, and PFH were 1.76 ± 1.03 mm, 4.22 ± 1.01 mm, and 5.98 ± 1.60 mm, respectively. The postoperative MRD1 was significantly increased and postoperative MRD2 was decreased significantly compared to preoperative values (both, P < 0.001). The preoperative and postoperative PFH values were not significantly different (P = 0.941). CONCLUSIONS It is important to assess the degree of reverse ptosis before surgery in patients that undergo ptosis surgery, and to remember that MRD2 and PFH may be reduced during surgery. Therefore, the position of the upper eyelid should be intraoperatively adjusted based on MRD1, not the PFH, to prevent overcorrection after surgery.