Anterior segment changes following Nd: YAG laser posterior capsulotomy: a quantitative ultrasound biomicroscopy study

Purpose: To evaluate the effects of neodymium-doped yttrium-aluminum-garnet (Nd: YAG) laser posterior capsulotomy on anterior segment parameters in pseudophakic eyes using ultrasound biomicroscopy (UBM). Methods: This prospective study included 35 pseudophakic eyes of 34 patients with visually significant posterior capsule opacification (PCO) following uncomplicated phacoemulsification with a one-piece hydrophobic acrylic intraocular lens. UBM was used to assess anterior segment parameters, including anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber width (ACW), lens vault (LV), and iris thickness (IT). The angle opening distances (AOD) at 500 mu m (AOD500), and at 750 mu m (AOD750), the angle recess area (ARA) at 500 mu m (ARA 500), the trabecular-iris space area at 500 mu m (TISA 500), and at 750 mu m (TISA 750) were measured both temporal and nasal area. The measurements were taken three times, the first time before the Nd: YAG capsulotomy, the second time 1 week after and the third time 1 month after the procedure. Results: No statistically significant changes were found in intraocular pressure (IOP), central corneal thickness, ACD, ACW, LV, or IT following capsulotomy. However, a significant and sustained increase was observed in angle-related parameters (ACA, AOD500/750, ARA500, and TISA500/750) at both 1 week and 1 month post-procedure(p < 0.05 for all). No significant changes were detected between the 1st week and 1st month measurements of angle-related parameters (p > 0.05 for all). Conclusion: Nd: YAG laser capsulotomy leads to significant widening of anterior chamber angle structures without affecting IOP or ACD. These findings suggest that the procedure is safe and may positively influence aqueous humor dynamics.