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.

Pattern reversal visual evoked response in retinitis pigmentosa.

PURPOSE: To determine if the pattern reversal visual evoked response (PVER) can objectively evaluate visual function in retinitis pigmentosa (RP). METHODS: We retrospectively reviewed the medical records of 29 patients (29 eyes) with RP, a visual acuity (VA) better than 20/100, and for whom an electroretinogram (ERG) and a PVER had been recorded. A steady-state PVER was measured using five check sizes: 160, 80, 40, 20 and 10 min of arc. The best-corrected VA was measured using the ETDRS chart. Visual fields (VFs) were measured using standard Goldmann perimetry. To quantify the VFs, we measured the field size (isopter IV-2) in four meridians and averaged them. Twenty-five eyes of 25 normal subjects served as controls. RESULTS: The mean and median VAs were 20/40 (logMAR = 0.30 +/- 0.20). The average VF (isopter IV-2 ) was 20 degrees (median, 9 degrees: range. 2 degrees to 62 degrees). All patients had a recordable PVER. Only 12 (41 %) patients had a recordable ERGs, all subnormal. The PVER amplitudes showed a relatively good correlation with VA in the intermediate check sizes (40 min of arc, r = 0.611. P = 0.0004: 20 min of arc, r = 0.596. P = 0.0007). The PVER amplitude-check size function had a flattened inverted V shape in the RP patients and an inverted U shape in the normal subjects, with the mean amplitudes for the RP patients significantly smaller than the normals at all check sizes. CONCLUSION: The PVER is a useful method for objectively evaluating the visual function in RP patients whose central vision is still preserved.