FAZ area measurements by means of OCT-A showed excellent reproducibility and repeatability in healthy eyes. OCT-A is a non-invasive diagnostic method, and its reliability makes it an interesting potential diagnostic tool for disease detection and follow-up in retinal pathologies involving foveal microcirculation.

Purpose To study neuroretinal alterations in patients affected by type 2 diabetes with no diabetic retinopathy (DR) or mild nonproliferative diabetic retinopathy (NPDR) and without any sign of diabetic macular edema. Patients and methods In total, 150 type 2 diabetic patients with no (131 eyes) or mild NPDR (19 eyes) and 50 healthy controls were enrolled in our study. All underwent a complete ophthalmologic examination, including Spectral-Domain optical coherence tomography (SD-OCT). Ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thickness values were calculated after automated segmentation of SD-OCT scans. Results Mean best-corrected visual acuity was 0.0 ± 0.0 LogMAR in all the groups. Mean GC-IPL thickness was 80.6 ± 8.1 μm in diabetic patients and 85.3 ± 9.9 μm in healthy controls, respectively (P = 0.001). Moreover, evaluating the two different diabetic groups, GC-IPL thickness was 80.7 ± 8.1 μm and 79.7 ± 8.8 μm in no-DR and mild-NPDR group (P = 0.001 and P = 0.022 compared with healthy controls, respectively). Average RNFL thickness was 86.1 ± 10.1 μm in diabetes patients and 91.2 ± 7.3 μm in controls, respectively (P = 0.003). RNFL thickness was 86.4 ± 10.2 μm in no-DR group and 84.1 ± 9.4 μm in mild-NPDR group (P = 0.007 and P = 0.017 compared with healthy controls, respectively). Conclusion We demonstrated a significantly reduced GC-IPL and RNFL thickness values in both no-DR and mild-NPDR groups compared with healthy controls. These data confirmed neuroretinal alterations are early in diabetes, preceding microvascular damages.

PURPOSE. To investigate correlations among macular ganglion cell complex (GCC) layer thickness, macular capillary density, and macular function in patients affected by retinitis pigmentosa (RP). METHODS.Fourteen patients (28 eyes) with previous diagnosis of RP were enrolled. The diagnosis of these conditions was made based on both clinical features and electrophysiological examination. All patients underwent a complete ophthalmologic examination, including optical coherence tomography angiography (OCTA) and multifocal electroretinogram (mfERG). Main outcome measures were macular GCC layer thickness; superficial capillary plexus (SCP) vessel density; deep capillary plexus (DCP) vessel density; choriocapillaris plexus (CCP) vessel density; and amplitudes of mfERG N1 and P1 waves.RESULTS. Average GCC thickness was significantly thinner in RP patients (76.0 6 25.1 and 109.2 6 17.5 lm, P ¼ 0.028). Superficial capillary plexus density was 42.2 6 3.4% in the RP group and 51.4 6 2.3% in the control group (P < 0.001). Deep capillary plexus density was reduced in RP patients (42.7 6 6.2%) after the comparison with healthy subjects (56.6 6 2.2%, P < 0.001). Choriocapillaris plexus density was significantly less in RP patients than in the control group (65.3 6 2.7% and 67.2 6 1.4%, P ¼ 0.024). Superficial capillary plexus and DCP density were significantly correlated with both mfERG values and GCC thickness.CONCLUSIONS. We showed that both choroid and retinal vessels were modified in RP patients after comparison with healthy subjects. Moreover, we demonstrated that the SCP and DCP vessel densities are correlated with the macular function, as well as with the GCC thickness.

In the last years, several studies have reported vascular factors playing an important role in AMD pathogenesis. We demonstrated that both superficial and deep retinal plexuses are altered among patients affected by AMD. Interestingly, this alteration starts immediately at the intermediate AMD stage and also the choroidal thickness reduction.