ABSTRACT
Purpose: The present study aims to determine the macular and choroidal optical coherence tomography angiography (OCTA) biomarkers in the assessment and monitoring of diabetic macular edema (DME) and diabetic macular ischemia (DMI) in patients with non?proliferative diabetic retinopathy (NPDR). Methods: In this cohort study, a total of 176 eyes of 110 patients with NPDR were investigated at our institute over a period of 10 months. Eyes were divided into four groups based on the severity of NPDR. Each eye was subjected to OCTA (Topcon 3D OCT?1 Maestro2) macula 6 × 6 mm2 en face. It features IMAGEnet 6 software for dynamic viewing of OCTA and imaging data. Four OCTA biomarkers for the macula were identified: foveal avascular zone area (FAZ area), foveal avascular zone contour irregularity (FAZ?CI), capillary dropout areas (CDA), and perifoveal intercapillary areas (PICA). The choroidal OCTA biomarker was the number of choroidal circulation flow voids (CCFV). For all analyses, P < 0.05 was considered statistically significant. Results: Increase in FAZ area and number of CDA were statistically significant (p < 0.0001) with an increase in central foveal thickness, suggesting a correlation of ischemic changes with an increase in DME. FAZ?CI, enlarged PICA, and CCFV were significantly associated with more severe NPDR patients. Conclusion: A correlation between DME and DMI in a patient of NPDR and its progression can be evaluated in a single visit. A unique feature of our study is it revealed novel diagnostic biomarkers of OCTA for DMI and DME.
ABSTRACT
PURPOSE: To evaluate the efficacy of optical coherence tomography angiography (OCTA) by measuring the foveal avascular zone (FAZ) area in patients with branch retinal vein occlusion (BRVO). METHODS: Thirty four eyes of 34 patients with BRVO were retrospectively reviewed. The area of the FAZ was calculated using fluorescein angiography (FAG) and OCTA. The FAZ area was divided into two groups according to the presence of macular edema, which was determined based on the central foveal thickness (300 µm), and then the measured areas were compared. RESULTS: Pearson's correlation analysis revealed a significant positive correlation between FAG and the superficial capillary plexus (SCP) in OCTA with or without macular edema (r = 0.845, p = 0.001). However, there was not a significant correlation between FAG and the deep capillary plexus (DCP) in OCTA (r = 0.001, p = 0.996). In addition, the FAZ area measured by FAG and OCTA in the SCP showed a significant agreement between the two methods (intraclass correlation coefficient [ICC] = 0.916, p = 0.001). However, there was no significant relation found for the FAZ area between FAG and OCTA in the DCP (ICC = 0.001, p = 0.501). CONCLUSIONS: In the patients with BRVO, OCTA can be used to measure the FAZ areas in both the SCP and DCP, beyond measurement of the FAZ area at the two-dimensional cross section used during FAG. The FAZ area in the SCP via OCTA showed a statistically significant correlation with the FAZ area determined by FAG, but there was no such correlation in the DCP. That said, the FAZ area in the DCP was positively correlated with a decrease in visual acuity among the patients, which may be an indicator of visual prognosis.