Changes in Anterior Segment Parameters Following Pars Plana Vitrectomy Measured by Ultrasound Biomicroscopy (UBM)

Despite being a posterior segment ocular surgery, pars plana vitrectomy (PPV) may also affect anterior segment parameters. We aimed to investigate anterior segment alterations following PPV using ultrasound biomicroscopy (UBM) to visualize the structural anatomy of the eye.
In this study, we enrolled phakic patients undergoing PPV (as the sole procedure). The anterior chamber depth, crystalline lens anterior-posterior (AP) diameter, anterior chamber angle, ciliary body dimensions, and integrity of the ciliary zonules and posterior capsule were assessed using UBM before and at least 3 months after PPV. Seven eyes from seven patients were included in the study. The indications for PPV were rhegmatogenous retinal detachment (57%), epiretinal membrane (29%), and macular hole (14%). The mean age of the patients was 57.86 ± 6.56 years, and they were followed up for a mean of 131.57 ± 29.99 days.
The crystalline lens AP diameter was the only parameter that changed significantly following PPV (p = 0.042). Thus, increases in the crystalline lens AP diameter, without significant changes in the anterior chamber depth, can be expected after PPV due to the development of nuclear sclerotic cataracts.