Ultrasound biomicroscopy after vitrectomy in eyes with normal intraocular pressure and in eyes with chronic hypotony.

PURPOSE To analyze the ultrasound biomicroscopy (UBM) features of eyes with chronic hypotony after pars plana vitrectomy (PPV) and compare them with the UBM features of eyes with normal intraocular pressure (IOP) after PPV. METHODS This comparative (nonrandomized) interventional study included 64 eyes of 64 patients who underwent PPV. Group 1 included 20 eyes with less complex vitreoretinal diseases (VRD) that presented with normal IOP after PPV. Group 2 included 44 eyes with severe proliferative vitreoretinopathy (PVR) managed with PPV and silicone oil tamponade that presented with complete retina reattachment and chronic ocular hypotony. UBM was performed to study the anterior segment, ciliary body (CB), and peripheral retina. The UBM findings of the two groups were compared. RESULTS In Group 1, 19/20 eyes presented with no CB alterations detected by UBM. In Group 2, 43/44 eyes presented with CB alterations that included tractional CB detachment (n=16); exudative CB detachment (n=11); tractional CB detachment/CB atrophy (n=7); CB hypotrophy (n=5); tractional CB detachment/exudative CB detachment (n=3); and CB edema (n=1). There was a strong relationship between IOP and CB findings revealed by UBM. CONCLUSIONS Eyes with hypotony following PPV have CB abnormalities that can be detected by UBM. These CB alterations were not found in eyes with normal IOP after PPV in this series.