scholarly journals Distance between the center of the FAZ measured automatically and the highest foveal bulge using OCT-angiography in elderly healthy eyes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takuhei Shoji ◽  
Hirokazu Ishii ◽  
Junji Kanno ◽  
Takanori Sasaki ◽  
Yuji Yoshikawa ◽  
...  

AbstractThe center of the fovea, termed the foveola, is the area of highest visual acuity, has the highest density of cone photoreceptors. We investigated the distance between the automatically-determined center of the foveal avascular zone (FAZ) and the manually-determined highest foveal bulge (FB) point using single swept-source optical coherence tomography angiography (OCTA) instrument. This cross-sectional study included 49 eyes of 49 individuals (34 women and 15 men; median age: 68 years) with no history of ocular disorders. The FAZ in the superficial capillary plexus was automatically determined using the Kanno–Saitama macro method, and the center of the FAZ was automatically determined using ellipse approximation. Another candidate foveal center, the highest FB point, was determined manually on the serial cross-sectional B-scan images. As a result, the foveal center was manually identified as the highest FB point on B-scan OCTA images. The center of the FAZ was more likely to be located inferior to the highest FB point (p = 0.031). In participants with a total (linear) distance of more than 50 μm between the center of the FAZ and the highest FB point, the displacement was significantly more in the horizontal direction than in the vertical direction (p = 0.017). These results can be applicable to further studies regarding the spatial relationships between the center of the FAZ and the highest FB point in various macular diseases or previously-treated eyes.

2021 ◽  
Author(s):  
Takuhei Shoji ◽  
Hirokazu Ishii ◽  
Junji Kanno ◽  
Takanori Sasaki ◽  
Yuji Yoshikawa ◽  
...  

Abstract The center of the fovea, termed the foveola, is the area of highest visual acuity, has the highest density of cone photoreceptors, and is the center of the foveal avascular zone (FAZ). We investigated the distance between the automatically-determined center of the foveal avascular zone (FAZ) and the manually-determined highest foveal bulge (FB) point using swept-source optical coherence tomography angiography (OCTA). This cross-sectional study included 49 eyes of 49 individuals (34 women and 15 men; median age: 68 years) with no history of ocular disorders. The FAZ in the superficial capillary plexus was automatically determined using the Kanno-Saitama Macro method, and the center of the FAZ was automatically determined using ellipse approximation. The foveal center was manually identified as the highest FB point on B-scan OCTA images. The center of the FAZ was more likely to be located inferior to the highest FB point. In participants with a combined distance of more than 50 µm between the center of the FAZ and the highest FB point, the displacement was significantly more in the horizontal direction than in the vertical direction (p = 0.017). These results can be applicable to further studies regarding the spatial relationships between the center of the FAZ and the highest FB point in various macular diseases or previously-treated eyes.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing Zhai ◽  
Wei Fang ◽  
Xueting Yu ◽  
Xinjie Ye ◽  
Lijie Hou

Abstract Background To quantify and compare retinal microvascular features using optical coherence tomography angiography (OCTA) in constant (XT) and intermittent exotropia (IXT). Methods An observational cross-sectional study was conducted from September 2020 to November 2020 at the Affiliated Eye Hospital of Wenzhou Medical University. OCTA examination was performed to evaluate the macular perfusion density of the deep capillary plexus (DCP), superficial capillary plexus (SCP), and foveal avascular zone (FAZ) parameters in XT and IXT patients, and in age-matched controls. The study parameters were analyzed. Results A total of 76 participants, including 16 (21%) XT patients, 24 (32%) IXT patients, and 36 (47%) controls, were recruited. The exodeviation angle was 39.06 ± 10.38 prism degrees (PD) at near and 43.00 ± 9.74 PD at distance in the XT group, and 27.13 ± 18.28 PD at near and 31.04 ± 18.82 PD at distance in the IXT group. The macular perfusion density of the DCP in 6 × 6-mm scans and the SCP in 3 × 3-mm scans were lower in the deviating eyes than in the fixating eyes of XT patients (p < 0.001, p = 0.032, respectively). The macular perfusion density of the DCP in the deviating eyes of XT and IXT patients was significantly lower than that of the controls. There was no significant difference in the FAZ parameters among the groups. Conclusions In XT patients, OCTA revealed lower macular perfusion density in deviating eyes than in fixating eyes and control eyes. IXT patients showed no difference between the two eyes, but the macular perfusion density of the DCP was lower than that of the controls.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Gao Jian ◽  
Xu Ya Jing ◽  
Li Yang ◽  
Liu Lun

Purpose. This study is aimed at quantifying the difference of the foveal microvasculature in the eyes with diabetic macular edema (DME) with and without subfoveal neuroretinal detachment (SND+ and SND-, respectively). Methods. This retrospective, cross-sectional study included 48 eyes from 42 patients with DME (20 SND+ and 28 SND- eyes). Data collection included fundus color photographs, optical coherence tomography angiography (OCTA), and best-corrected visual acuity. The following parameters were evaluated with OCTA: foveal avascular zone (FAZ) parameters and vessel density in a width of 300 μm around the FAZ, superficial capillary plexus, deep capillary plexus (DCP), and choriocapillary plexus. The number of retinal hyperreflective spots (HRS) and the area of SND in the central 3 mm were evaluated at 0 degrees using B-scans. Results. Parafoveal vessel densities of DCP were significantly lower in SND+ than in SND- eyes (p<0.001). The number of HRS was significantly higher in SND+ than in SND- eyes (p<0.001). A statistically significant negative correlation between parafoveal vessel density in DCP and the number of HRS in all eyes was found (Spearman’s correlation, r=0.389, p=0.006). Conclusion. DME with SND correlated with larger numbers of HRS and significant macular microvascular impairment in the DCP. The pathophysiology of decline of parafoveal vessel density in the DCP with an increase in the number of HRS in the eyes with DME with SND needs further investigation.


2020 ◽  
pp. bjophthalmol-2019-315520
Author(s):  
Jinfeng Zhao ◽  
Zhenquan Wu ◽  
Waiching Lam ◽  
Mingmin Yang ◽  
Lu Chen ◽  
...  

PurposeTo compare the foveal microvascular structure characteristics in children with a history of intravitreal injection of ranibizumab (IVR) versus laser photocoagulation (LP) for retinopathy of prematurity by optical coherence tomography angiography (OCTA).MethodsIn this cross-sectional study, a total of 17 children (28 eyes) underwent IVR and 20 children (37 eyes) underwent LP were recruited. The age of doing OCTA examination of the two groups are 5.4±1.1 years and 6.3±1.8 years, respectively (p=0.07). Spectral-domain OCTA was performed for all the eyes with a scan size of 3×3 mm. The data of the superficial retinal layer were analysed. The foveal avascular zone (FAZ) and vessel density (including vessel length density (VLD) and perfusion density (PD)) were measured using the software of OCTA (Cirrus AngioPlex 5000, Carl Zeiss, Meditec, Dubin, California, USA). The central foveal thicknesses (CFT) were measured by cross-sectional OCT.ResultsIn the central fovea, the retinal VLD and PD of patients with IVR were 13.82±2.99 mm/mm2 and 0.25±0.05 mm2/mm2, respectively, which were significantly lower than those of the LP group (15.64±2.71 mm/mm2 and 0.28±0.05 mm2/mm2, p=0.01 and p=0.006). The FAZ area of patients with IVR and LP were 0.13±0.09 mm2 and 0.09±0.07 mm2, respectively (p=0.048). The CFT of patients with IVR and LP were 200.7±16.7 µm and 220.9±22.7 µm, respectively (p<0.01). The logarithm of the minimal angle of resolution best-corrected visual acuity of patients with IVR and LP were 0.2±0.1 and 0.1±0.1, respectively (p=0.01). There was no significant difference in the parafoveal and foveal VLD and PD, FAZ morphological index and spherical equivalent refraction (SER) between the two groups.ConclusionThe IVR might contribute to microvascular changes in the macular zone, such as reducing the central foveal VLD and PD, while the LP might contribute to microstructural changes, such as smaller FAZ and thicker CFT.


2018 ◽  
Vol 103 (8) ◽  
pp. 1173-1178 ◽  
Author(s):  
Ahmad M Mansour ◽  
Michael W Stewart ◽  
Salma W Yassine ◽  
Carl-Joe Z Mehanna ◽  
Antonio Marcelo B Casella ◽  
...  

AimTo study the macular structure and vasculature in consecutive nanophthalmic eyes using optical coherence tomography angiography.MethodsThis is a prospective, multicentre, cross-sectional study of patients with nanophthalmos (one or both eyes). The superficial and deep foveal avascular zones (FAZ) were measured both manually and with the machine’s built-in automated measurement tool. Correlations between best corrected visual acuity (BCVA), central macular thickness (CMT) and subfoveolar choroidal thickness (SFCT) were calculated.ResultsSixty-five eyes of 35 subjects (16 men and 19 women) with a mean age of 37.4 years were analysed. The mean±SD of refractive error was 14.3±3.2 dioptres, axial length was 16.4±1.6 mm, CMT was 410.2±128.3 µm and SFCT was 450.1±108.3 µm. FAZ was unmeasurable small size in both the superficial and deep capillary plexus in all eyes, along with tortuosity of the superficial foveal capillaries and large vessels. Foveal folds were present in 29 eyes. Disc drusen was detected in 27 eyes and was absent in 31 eyes, while fundus autofluorescence was positive in 17 and negative in 24 eyes. BCVA varied from 20/20 to 20/800, with a mean of 20/76. Using Spearman’s correlation, logarithm of the minimum angle of resolution BCVA correlated negatively with axial length (r=−0.30; p=0.015).ConclusionsFAZ attenuation, capillary tortuosity, foveal folds and thickened subfoveal choroid characterise the nanophthalmic macula. These findings may result from a redundant retina and the absence of apoptotic foveolar retraction because of developmental arrest of the optic vesicle after closure of the embryonic fissure.


Author(s):  
Fariba Ghassemi ◽  
Vahid Hatami ◽  
Farhad Salari ◽  
Fatemeh Bazvand ◽  
Hadi Shamouli ◽  
...  

Abstract Background This study aimed at defining the variance of vessel density (VD) characteristics in the macula of children with normal eyes. Methods This was a cross-sectional study in which subjects with normal eyes aged 3–18 years were enrolled. The macula was scanned by optical coherence tomography angiography (OCTA). Four age groups as under 7 years, 7–10 years, 11–14 years and more than 14 years of age were defined. The influences of age, gender, and body mass index on VD were analyzed. Results A total of 108 normal eyes from 54 participants with a mean age of 10.9 years were enrolled in the study. At the superficial and deep retina capillary plexus (SCP and DCP) and choriocapillaris (CC), respectively, the mean VD of the fovea was 20.10%, 36.99%, and 75.67%; at parafovea, these measurements were 53.12%, 55.81%, and 69.76%; and at perifovea, these measures were 51.38%, 52.46%, and 73.47%. The median foveal avascular zone (FAZ) was 0.30 mm2. No significant differences between superior-hemi VD and inferior-hemi VD were found in the studied plexuses. The VD at parafovea and perifovea CC differed significantly between groups. There was no variation in VD of macular retina and CC between eyes or sex. FAZ areas were different between genders. Conclusions No difference between eyes and genders in the retina and CC VD of macular area was noted. FAZ area was larger in male. Even though this is not a longitudinal study, it may provide us with hints about macular vascular development during puberty and clinical implications of OCTA in children.


2021 ◽  
Author(s):  
Jiahui Liu ◽  
Xia Gong ◽  
Xiong Kun ◽  
Wei Wang ◽  
Yuting Li ◽  
...  

AbstractObjectivesTo evaluate the associations of retinal vascular complexity features with the severity of diabetic retinopathy (DR) by using non-invasive optical coherence tomographic angiography (OCTA).MethodsThis prospective cross-sectional study recruited ocular-treatment-naïve patients with type 2 diabetes mellitus registered in the community of Guangzhou, China. The OCTA was used to obtain the measurements of fractal dimension (FD) and blood vessel tortuosity (BVT) in superficial capillary plexus (SCP) and the deep capillary plexus (DCP). The univariate and multivariate linear regression was used to analyze the correlation of FD and BVT in different layers with DR severity.ResultsA total of 1282 patients (1282 eyes) were included, with a mean age of 64.2±7.8 years, 60.81% of male. The FD in DCP decreased and BVT in DCP increased in DR patients compared to non-DR patients, even after adjusting for confounding factors (P< 0.05). Trend analysis showed a significant decrease in FD values as DR progresses, while the BVT progressively increased with worsening DR severity (P< 0.01).ConclusionThe FD and BVT determined using OCTA might be useful parameters for objectively distinguishing DR from non-DR, and indicating the DR progression.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dunja Bajtl ◽  
Mirjana Bjeloš ◽  
Mladen Bušić ◽  
Ana Križanović ◽  
Leon Marković ◽  
...  

Abstract Background The purpose of this cross-sectional study involving healthy emmetropic four-year-old Caucasian children was to provide a macular perfusion normative database acquired with optical coherence tomography angiography (OCTA). One eye of each examinee underwent OCTA imaging. The following parameters were analyzed using AngioTool Image J software: vessels area (VA), vessels density (VD), total number of junctions (TNJ), junctions density (JD), total vessel length (TVL), average vessel length (AVL), total number of endpoints (TNEP), lacunarity (L), vessel diameter index (VDI), tortuosity (T) and foveal avascular zone (FAZ). Average central macular thickness (CMT) and average central macular volume (CMV) were measured. Result Sixty-two eyes of 62 children of average age 50.4 ± 3.8 months were examined. VA, VD, and T increased from the inner towards the outer layers of the retina. The intermediate capillary plexus had the highest JD and TNEP and narrowest FAZ. Retinal sexual differentiation was supported with higher values of the retinal VA, VDI and TNEP, and chorioretinal VA, VDI and L in males. The choriocapillaris presented with the highest VD, AVL, and T and the lowest L and TNEP. Conclusion The study provides the first detailed normative database of the macular vascular network in the youngest uniform cohort of emmetropic four-year-old children.


2020 ◽  
Author(s):  
Laura Gutierrez-Benitez ◽  
Yolanda Palomino ◽  
Noe Casas

PURPOSE: To develop and evaluate an automated method to measure the foveal avascular zone (FAZ) area in healthy eyes on Heidelberg Spectralis Optical Coherence Tomography Angiography (HS-OCTA). This method is referred to as the modified Kanno-Saitama macro (mKSM). METHODS: This cross-sectional study included 29 eyes of 25 healthy volunteers who underwent HS-OCTA at the macular area twice at the same time. Regardless of the quality of the images, all of them were included. Macular data on the superficial vascular plexus, intermediate capillary plexus and deep capillary plexus were processed by mKSM. The FAZ area was measured twice automatically using the mKSM and twice manually by two independent examiners. RESULTS: Intrascan intraclass coefficient ranged from 0,948 to 0,993 for manual measurements and was 1 for mKSM method. Interscan intraclass coefficients ranged from 0,925 to 0,973 for manual measurements and from 0,770 to 0,902 for mKSM method. Despite that the difference between human examiners is smaller than between human examiners and mKSM according to Bland-Altman plots, the scatterplots show a strong correlation between human and automatic measurements. The best results are obtained in intermediate capillary plexus. CONCLUSIONS: Automated determination of the FAZ area in HS-OCTA is feasible and less human-dependent by mKSM even if the image is not perfectly centred or has artefacts. The mKSM processing could contribute to our understanding of the three vascular plexuses.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Nina C. B. B. Veiby ◽  
Aida Simeunovic ◽  
Martin Heier ◽  
Cathrine Brunborg ◽  
Naila Saddique ◽  
...  

Background/Objective. Optical coherence tomography angiography (OCTA) is increasingly used to supplement ophthalmoscopy in the diagnosis and follow-up of diabetic retinopathy. Our objective was to confirm if OCTA parameters can predict the development of nonproliferative diabetic retinopathy (NPDR) and to clarify if any single OCTA parameter is associated with NPDR independently of well-known risk factors in young type 1 diabetes (T1D) patients. Methods. OCTA of both eyes was performed in a cross-sectional study of 14 to 30-year-old individuals with at least 10-year duration of T1D and controls recruited from the Norwegian Atherosclerosis and Childhood Diabetes (ACD) study. Vessel density (VD) and foveal avascular zone (FAZ) area in the superficial and deep capillary plexus (SCP and DCP), total retinal volume (TRV), and central macular thickness (CMT) were calculated using automated software. Univariate and multivariate ordered logistic regression (OLR) models were used accordingly. Results. We included 168 control eyes and 315 T1D eyes. Lower VD in DCP (OR 0.65, 95% CI 0.51–0.83), longer diabetes duration (OR 1.51, 95% CI 1.22–1.87), and higher waist circumference (OR 1.08, 95% CI 1.02–1.14) were significantly associated with progression of NPDR. VD in SCP and DCP were significantly lower in T1D patients without diabetic retinopathy than in controls. Conclusions. Sparser VD in DCP is significantly associated with severity of NPDR, supporting that OCTA might detect the earliest signs of NPDR before it is visible by ophthalmoscopy.


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