Foveal avascular zone area measurement in diabetic patients: Superficial, deep or combined retinal vascular complex?

To compare differences in the foveal avascular zone (FAZ) area, measured in the Superficial Vascular Complex (SVC), Deep Vascular Complex (DVC) and a combined analysis of both (SDVC), using two Spectral Domain OCT angiography (OCT-A) protocols, High Speed (HS) and High Resolution (HR). A total of 26 eyes of diabetic patients, with and without macular oedema, were examined with two different fovea centered OCT-A volume scans. The two protocols were HS and HR volume scans, and the foveal avascular zone was manually measured in the SVC, DVC, and SDVC slabs by two masked investigators. Inter and intraoperator variability was analysed using Intraclass Correlation Coefficient (ICC) and differences were compared between the HR and HS acquisitions throughout the different vascular slabs. Intraoperator variability was low in all slabs (ICC > 0.9) and interoperator variability was lower for HR (ICC 0.835-0.911) compared to HS (ICC between 0.604 and 0.865). Comparing HS and HR measurements for the same slab, the correlation was only moderate in SVC and DVC (ICC was 0.640 and 0.568 respectively) but was good in the SDVC (ICC = 0.823). FAZ area measurement in SDVC also showed the smallest bias (mean difference 0.009 mm2) and the narrowest limits of agreement (-0.175 to 0.193 mm2). Even in cases of diabetic macular oedema, when measuring the FAZ area, the reproducibility was better between HS and HR protocols when using the SDVC slab, compared to the SVC or DVC slabs alone. Further studies should evaluate the use of the combined SDVC slab for the FAZ assessment, compared to the SVC and DVC slabs alone, in the detection and progression of different retinal diseases.

Pereira B ，Faria R ，Domingues C ，Barros A ，Varandas T ，Henriques J ，Nascimento J ，Carolino E ，Camacho P ... -  《-》

A Comparison of Optical Coherence Tomography Angiography Metrics and Artifacts on Scans of Different Sizes in Diabetic Macular Ischemia.

Tsai WS ，Thottarath S ，Gurudas S ，Pearce E ，Yamaguchi TCN ，Sivaprasad S ... -  《-》

Colocalization of Ellipsoid Zone Disruption With Capillary Nonperfusion in Different Retinal Vascular Layers and Choriocapillaris on En Face OCT of Diabetic Patients.

To assess the colocalization of ellipsoid zone (EZ) disruption with nonperfusion in choriocapillaris (CC), retinal superficial capillary plexus (SCP), and deep capillary plexus (DCP) in diabetic patients using en face optical coherence tomography (OCT) and OCT angiography (OCTA). Macular OCT and OCTA scans (3 × 3 mm) of 41 patients with diabetic retinopathy were obtained using an RTVue XR Avanti instrument. After correcting the shadow artifacts, EZ integrity was assessed in the en face OCT slab using the Gaussian mixture model clustering method compared with the corresponding EZ en face OCT of 11 age-matched normal patients. A similar technique was used for detecting capillary nonperfusion using CC en face OCTA. Geometric perfusion density (GPD) maps were also generated for the SCP and DCP. Maps of capillary nonperfusion in the CC, SCP, and DCP were compared pixel by pixel with the map generated from EZ disruption. Twenty-one patients with diabetic macular edema (DME) and 20 patients with diabetic retinopathy without macular edema were included in this study. In both groups, the overlap of EZ disruption was significantly greater with choriocapillaris nonperfusion than with nonperfusion in the SCP and DCP (dry macular group: 33.15% with CC vs. 0.46% with SCP vs. 1.70% with DCP, p < 0.001; DME group: 29.81% with CC vs. 1.22% with SCP vs. 6.25% with DCP, p < 0.001). In multivariate analysis, after adjusting for stage of diabetic retinopathy and DME, EZ disruption was only associated with nonperfusion in CC (p value = 0.03). According to the linear regression model, there was a statistically significant correlation between logMAR visual acuity and EZ disruption in the dry macular group (p = 0.041). In patients with diabetic retinopathy, choriocapillaris nonperfusion may play a more significant role in photoreceptor loss than retinal nonperfusion.

Mirshahi R ，Rahdar A ，Ahmadi MJ ，Fadakar K ，Torkashvand A ，Nekoozadeh S ，Falavarjani KG ... -  《-》

The central retina vessel density and foveal avascular zone values of 792 healthy adults using optical coherence tomography angiography.

To determine normal macular vessel density (VD) and foveal avascular zone (FAZ) values using optical coherence tomography angiography (OCTA) analysis in healthy adults. As part of the Prospective Epidemiological Research Studies in Iran (PERSIAN) Organizational Cohort study at Mashhad University of Medical Sciences (POCM), we conducted a cross-sectional study using 3 × 3 and 6 × 6 mm OCTA scans to evaluate the VD of the macular superficial capillary plexus (SCP), deep capillary plexus (DCP), and the FAZ area in healthy adults. The study included 792 participants, with a mean age of 39.8 ± 6.8 years. There were 359 males with a mean age of 39.9 ± 7.8 years and 440 females with a mean age of 39.4 ± 6 years. The mean values of various parameters were measured, including the right eye whole image SCP and DCP VDs, FAZ area, FAZ perimeter, and fovea VD in a 300 µm wide zone around FAZ (FD). These values were found to be 45.9 ± 2.6%, 50.2 ± 3%, 0.3 ± 0.1mm2, 2.1 ± 0.4 mm, and 50.4 ± 3.3%, respectively. Females and younger participants had significantly higher mean values of whole image SCP and DCP VDs. Additionally, all FAZ parameters had significantly higher values in females, while younger participants had significantly higher mean FD values. Simple linear regression analyses showed that age was negatively correlated with right eye SCP and DCP VDs. Our study established standard SCP and DCP VD values influenced by age and gender. Age correlates negatively with both, DCP VDs correlate negatively with height and weight, and SCP VDs correlate positively with diastolic blood pressure.

Heidarzadeh HR ，Abrishami M ，Ebrahimi Miandehi E ，Shoeibi N ，Ansari Astaneh MR ，Hosseini SM ，Abrishami M ，Eslami S ，Bolouki A ... -  《-》

Early subclinical macular disease in asymptomatic patients with primary antiphospholipid syndrome: A quantitative multimodal retinal evaluation.

Zacharias LC ，Neto TDSR ，Dias da Silva Neto E ，Monteiro MLR ，Balbi GGM ，Signorelli F ，Higashi AH ，Bonfá E ，de Andrade DCO ... -  《-》