Quantifiable Improvement in True Downslanting Palpebral Fissure Morphology Following Upper Blepharoplasty: Analysis of Canthal Position and Fissure Inclination

In the domain of eyelid plastic surgery, lateral tissue release combined with upper blepharoplasty (via transcutaneous incision) is an effective intervention for patients with "sad eyes"-characterized by preoperative DH ≤ 2 mm, AX ＜ 10 degrees, and a downward-sloping lateral lower eyelid contour. This surgical approach not only significantly increases key structural parameters (DH, AX, AMV, and ALV; all P < 0.05) to correct the downward-slanting palpebral fissure but also alleviates soft tissue tension, restores the eyelid's natural curvature, and enhances its aesthetic vitality. Notably, the procedure yields consistent therapeutic effects even in the subgroup of patients with concurrent medial epicanthus, further substantiating the scientific validity and clinical efficacy of this surgical technique. Beyond aesthetic improvement, the correction of the "sad-appearing" facial phenotype concomitantly boosts patients' psychological confidence and willingness to engage in social interactions. Collectively, these findings support the clinical application of lateral tissue release as a reliable, patient-centered strategy for addressing "sad eyes" and optimizing both functional and aesthetic outcomes of eyelid plastic surgery.