Retinal microvascular alterations related to diabetes assessed by optical coherence tomography angiography

Abstract

Fluorescein angiography has been so far the gold-standard test to assess diabetic macular ischemia (DMI), a cause of irreversible visual impairment in diabetic patients. The aim of this study was to investigate foveal avascular zone (FAZ) and perifoveal microcirculation changes in eyes with nonproliferative diabetic retinopathy (NPDR) using optical coherence tomography angiography (OCTA), a new and noninvasive vascular imaging technique.Cross-sectional study including eyes of diabetic patients with NPDR.All patients underwent medical history, best-corrected visual acuity (BCVA) measurement, slit-lamp and fundus examination, multicolor imaging, SD-OCT, and swept-source OCT. OCTA was performed in order to assess macular superficial and deep capillary plexus, and swept-source OCT was performed to evaluate the central choroidal thickness.Fifty-eight eyes of 35 patients with a mean age of 61.8 years (±12.1) with mean HbA1C level of 7.6% (±1.5) were included in this study. Among them, 19 eyes had mild NPDR, 24 eyes had moderate NPDR, and 15 eyes had severe NPDR. There was a significant progression between NPDR stages for FAZ grade (P < 0.0001), surface (P = 0.0036) and perimeter (P = 0.0001), and for superficial capillary plexus nonperfusion index (NPI) (P = 0.0009). Moreover, a significant correlation was found between NPI and BCVA (P = 0.007).OCT angiography is a useful noninvasive tool to explore early phases of diabetic retinopathy, which are not routinely explore with fluorescein angiography and not precisely enough with color photographs. NPI and foveal avascular zone parameters are correlated with glycated hemoglobin in patients with NPDR. If confirmed by further studies, these results could represent a mean to sensibilize diabetic patients to their disease.

Intra- and Interdevice Deviation of Optical Coherence Tomography Angiography

“…This may even allow for more objective or even automated diagnosis and staging down the road [23]. Recently, Gozlan et al published that FAZ parameters are also correlated with glycated hemoglobin in patients with non-proliferative diabetic retinopathy [24]. All mentioned publications indicate that OCT-A FAZ measurements yield additional clinical information regarding disease severity and progression in retinal vasculopathies.…”

Assessment of morphological and functional alterations in patients with early stage of non-proliferative diabetic retinopathy by optical coherence tomography angiography and microperimetry

“…Our OCTA data demonstrated a markedly enlargement of the FAZ in NPDR cohorts, which is in line with previous reports. [16][17] [18] The FAZ is responsible for epicritic vision and central vision and has been reported to be larger in DR using FFA. [19][20] The enlargement of the FAZ is strongly related to capillary occlusion and retinal ischemia, which is one major pathophysiological mechanisms of DR. [16] However, accurate FAZ measurements are usually limited by the quality of FFA images.…”

“…[16][17] [18] The FAZ is responsible for epicritic vision and central vision and has been reported to be larger in DR using FFA. [19][20] The enlargement of the FAZ is strongly related to capillary occlusion and retinal ischemia, which is one major pathophysiological mechanisms of DR. [16] However, accurate FAZ measurements are usually limited by the quality of FFA images. [21] OCTA believed to be more accurate than FFA to demarcate and measure the FAZ, as it is not obscured by leakages, pooling or staining from fluorescein.…”

Evaluation der automatisierten Messung von ischämischen Veränderungen der Makula bei diabetischer Makulopathie

“…Der mittlere Umfang und die mittlere Zirkularität der FAZ in unserer Kohorte waren vergleichbar mit anderen Studien [25,31,32]. Ein statistisch signifikanter Unterschied bezüglich dieser Messwerte zwischen verschiedenen Stadien der NPDR konnte ebenfalls bereits nachgewiesen werden [31].…”