Prospective Evaluation of Iridocorneal Angle and Anterior Segment Changes Following Lower Eyelid Blepharoplasty: Evidence of Transient, Reversible Ocular Biomechanical Alterations

PURPOSE: To investigate early postoperative changes in intraocular pressure (IOP) and anterior segment morphology, after lower eyelid blepharoplasty, and to determine whether these alterations are transient or persistent. To our knowledge, this is among the first studies to prospectively quantify ICA dynamics following lower eyelid surgery. METHODS: This prospective study included 33 eyes of 33 patients undergoing lower eyelid blepharoplasty between November 2024 and February 2025. IOP was measured by Goldmann applanation tonometry. Scheimpflug-based tomography assessed central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), iridocorneal angle (ICA), axial length (AL), and pupil diameter (PD) preoperatively and on postoperative days 1 and 7. Nonparametric statistics were used (Friedman test with Holm-adjusted Wilcoxon post-hoc comparisons). RESULTS: A significant transient IOP elevation was observed on postoperative day 1 (p < 0.001), normalizing by day 7 (p = 0.94). The ICA significantly narrowed from 33.56° to 30.03° on day 1 (p < 0.001) and partially reopened to 33.27° by day 7 (p < 0.001). Similar reversible reductions were found in ACD, AL, and ACV (all p < 0.001). CCT and PD remained stable (p > 0.05). CONCLUSIONS: Lower eyelid blepharoplasty induces short-lived biomechanical changes in anterior segment configuration, most notably a transient narrowing of the iridocorneal angle, an underreported finding in blepharoplasty literature. These reversible alterations likely result from temporary orbital pressure changes rather than structural damage. Preoperative gonioscopy and postoperative IOP monitoring are advisable, especially in glaucoma or narrow-angle suspects.