scholarly journals Magnification Effect of Foveal Avascular Zone Measurement Using Optical Coherence Tomography Angiography

2020 ◽  
Vol 5 (2) ◽  
pp. 1-8
Author(s):  
Mika Suda ◽  
Yuji Yoshikawa ◽  
Gaku Terauchi ◽  
Soiti Matsumoto ◽  
Takuhei Shoji ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Axial Length ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
En Face ◽  
Avascular Zone ◽  
The Mean ◽  
The Relationship ◽  
Magnification Effect

Purpose: The aim of this study was to evaluate the foveal avascular zone (FAZ) of healthy subjects and examine the magnification effect. Methods: A total of 33 healthy volunteers were enrolled and all subjects were eligible for analysis. Optical coherence tomography angiography (OCTA) examination scanned 3 × 3 mm of the macular area. The FAZ area was measured on the superficial OCTA en face image with and without correction by axial length. The relationship between changes in the FAZ area after correction with the axial length was examined. Results: The mean age was 21.9 ± 0.6 years. The mean axial length was 24.87 ± 1.17 mm and mean spherical equivalent (SE) value was –3.64 ± 2.83 diopters (D). The FAZ area was 0.26 ± 0.10 mm2 before the axial length correction and 0.27 ± 0.10 mm2 after the correction. In the eyes that had an axial length longer than or equal to 26 mm or SE less than or equal to –6 D, the FAZ area after correction was significantly larger than that before correction (p < 0.01). The change of FAZ area after correction with axial length was significantly correlated with the axial length (R2 = 0.88, p < 0.01) or SE value (R2 = 0.55, p < 0.01). Conclusion: FAZ areas were comparable to previous reports. In high myopic cases, the magnification effect needs to be considered when evaluating the FAZ area.

scholarly journals Personalized analysis of foveal avascular zone with optical coherence tomography angiography

2017 ◽  
Vol 10 (4) ◽  
pp. 32-40
Author(s):  
Maria A Burnasheva ◽  
Alexey N Kulikov ◽  
Dmitrii S Maltsev
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Free Zone ◽  
Avascular Zone ◽  
The Mean ◽  
The Relationship ◽  
Free Area

Aim. To investigate the relationship between the foveal avascular zone (FAZ) and inner nuclear layer (INL) - free zone in order to provide a personalized approach for evaluation of the FAZ area with optical coherence tomography-angiography (OCTA). Material and methods. Thirty-six healthy individuals (36 eyes) and 9 patients (12 eyes) with nonproliferative diabetic retinopathy (nPDR) were included in this study. The FAZ area as well as INL-free zone were measured in superficial capillary plexus on OCTA images. The FAZ area, INL-free area, and the ratio of the INL-free area to the FAZ area were compared between healthy subjects and nPDR patients. Results. The mean FAZ area in healthy subjects and nPDR patients was 0.33 ± 0.1 and 0.56 ± 0.28 mm2 (p < 0.05), respectively. The mean INL-free zone in healthy subjects and nPDR patients was 0.33 ± 0.07 and 0.28 ± 0.1 mm2 (p > 0.05), respectively. The ratio of the INL-free area to the FAZ area in healthy subjects and nPDR patients was 1.08 ± 0.25 and 0.57 ± 0.2 (p < 0.001), respectively. Receiver operating characteristic analysis showed that the ratio of the INL-free area to the FAZ area had the higher area under curve (0.98; 91.7% sensitivity and 97.2% specificity) compared to the FAZ area (0.8; 66.7% sensitivity and 87.1% specificity) for differentiating nPDR from healthy eyes. Conclusion. This study showed that personalized analysis of the FAZ area based on the relationship between the actual FAZ and INL-free zone has better diagnostic accuracy compared to the conventional FAZ area measurement on OCTA images. (For citation: Burnasheva MA, Kulikov AN, Maltsev DS. Personalized analysis of foveal avascular zone with optical coherence tomography angiography. ­Ophthalmology Journal. 2017;10(4):32-40. doi: 10.17816/OV10432-40).

scholarly journals Comparison of Superficial and Deep Foveal Avascular Zone Area in Healthy Subjects Using Two Spectral Domain Optical Coherence Tomography Angiography Devices

2020 ◽  
Author(s):  
Pasha Anvari ◽  
Amin Najafi ◽  
Reza Mirshahi ◽  
Mahsa Sardarinia ◽  
Maryam Ashrafkhorasani ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Spectral Domain ◽  
Foveal Avascular Zone ◽  
Retinal Layer ◽  
Optical Coherence ◽  
Retinal Layers ◽  
Avascular Zone ◽  
The Mean

Purpose: To compare the area of the foveal avascular zone (FAZ) in the superficial and deep retinal layers using two different spectral-domain optical coherence tomography angiography (OCTA) devices. Methods: A cross-sectional comparative study was conducted to obtain macular OCTA images from healthy subjects using Optovue RTVue XR Avanti (Optovue, Inc, Fremont, CA) and Spectralis HRA+OCTA (Heidelberg Engineering, Heidelberg, Germany). Two independent trained graders measured the FAZ area using automated slab segmentation. The FAZ area in the superficial and deep retinal layers were compared. Results: Twenty-three eyes of 23 subjects were included. The graders agreement was excellent (>0.86) for all measurements. The mean FAZ area was significantly larger at the superficial retinal layer as compared to the deep retinal layer on both devices (0.31 ± 0.08 mm2 vs 0.26 ± 0.08 mm2 in Optovue and 0.55 ± 0.16 mm2 vs 0.36 ± 0.13 mm2 in Spectralis, both P < 0.001). The mean FAZ area was significantly greater in the superficial and deep retinal layers using Spectralis as compared to Optovue measurements (P < 0.001 for both comparisons). Conclusion: In contrast to previous reports, the FAZ area was larger in the superficial retina as compared to deep retinal layers using updated software versions. Measurements from different devices cannot be used interchangeably.

ENLARGEMENT OF FOVEAL AVASCULAR ZONE IN DIABETIC EYES EVALUATED BY EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

Retina ◽  
2015 ◽  
Vol 35 (11) ◽  
pp. 2377-2383 ◽  
Author(s):  
Noriaki Takase ◽  
Miho Nozaki ◽  
Aki Kato ◽  
Hironori Ozeki ◽  
Munenori Yoshida ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
En Face ◽  
Avascular Zone

Optical coherence tomography angiography findings in young β-thalassemia patients

2020 ◽  
Vol 30 (3) ◽  
pp. 600-607
Author(s):  
Elif Güler Kazancı ◽  
Muhammet Furkan Korkmaz ◽  
Mehmet Erol Can
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Control Group ◽  
Study Group ◽  
Optical Coherence ◽  
Avascular Zone ◽  
Capillary Plexus ◽  
The Mean ◽  
Superficial Capillary Plexus

Purpose: The purpose was to evaluate retinal vascular parameters by optical coherence tomography angiography in β-thalassemia major patients. Methods: Thirty-three patients with β-thalassemia major (study group) and 29 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. The mean foveal avascular zone, non-flow area, foveal avascular zone perimeter, acircularity index of foveal avascular zone, foveal density, the superficial capillary plexus, and deep capillary plexus were scanned using 6 × 6 mm optical coherence tomography angiography scans centered on the macula. Superficial capillary plexus and deep capillary plexus were also scanned centered on the optic disk. We collected data on histories of patients, and hemoglobin and ferritin were also studied from both groups. Results: The mean age was 13.85 ± 4.69 years (range: 4–21 years) in β-thalassemia major group and 12.59 ± 3.66 years (range: 6–18 years) in the control group. The mean foveal avascular zone value was 0.265 ± 0.11 mm2 in the study group and 0.296 ± 0.12 mm2 in the control group. The mean non-flow area value was 0.468 ± 0.12 mm2 in the study group and 0.479 ± 0.14 mm2 in the control group ( p > 0.05). Differences in the mean values for foveal density and acircularity index were statistically significant between the study group and control group ( p < 0.05, p = 0.026, and p = 0.026, respectively). Superficial capillary plexus and deep capillary plexus were not a significant difference between the study and control groups in 6 × 6 mm scans on macula and 4.5 × 4.5 mm scans on optic disk area ( p > 0.05). Acircularity index was negatively correlated ( r = −0.292, p = 0.026), and foveal density was positively correlated with hemoglobin ( r = 0.292, p = 0.026). Conclusion: By using optical coherence tomography angiography, we detected foveal microvascular changes in young β-thalassemia patients before significant ocular anomalies development.

scholarly journals Correlations among age, sex, axial length, and subfoveal choroidal thickness in the choriocapillaris structure analyzed using multiple en face image averaging optical coherence tomography angiography

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259880
Author(s):  
Ai Ichioka ◽  
Sotaro Ooto ◽  
Akihito Uji ◽  
Saki Manabe ◽  
Chieko Shiragami ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Axial Length ◽  
Choroidal Thickness ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Swept Source ◽  
Face Images ◽  
En Face ◽  
Flow Void ◽  
The Mean

Purpose To analyze the structure of the choriocapillaris in healthy eyes by using averaged en face images acquired using swept source optical coherence tomography angiography and to examine the changes in the macular profile in relation to age, sex, axial length, and choroidal thickness. Methods This prospective, cross-sectional study included 81 eyes of 81 subjects without ophthalmologic or systemic diseases who underwent a full ophthalmologic examination, including 3 × 3-mm macular optical coherence tomography angiography. Four to nine choriocapillaris en face images were registered and averaged. The averaged images were then binarized and analyzed. Results The averaged choriocapillaris images showed a continuous capillary meshwork, whereas the unaveraged images had a granular appearance. The mean total area and size of flow voids were 0.99 ± 0.20 mm2 and 567.8 ± 201.5 μm2, respectively, and these values correlated positively with age (p = 0.002, R = 0.336 and p = 0.026, R = 0.247, respectively). Age-related gains in the mean total area and flow void size were 4.20 × 10−3 mm2 and 3.07 μm2 per year, respectively. However, the mean total area and flow void size had no significant correlation with axial length, subfoveal choroidal thickness, or sex. Conclusions Multiple averaged en face swept source optical coherence tomography angiography is more effective than a single optical coherence tomography angiography scan for better visualizing the choriocapillaris. The total area and size of flow voids within a 3 × 3-mm macular area positively correlated with age. This technique can be useful for investigating the changes arising in macular diseases.

Quantitative assessment of the effect of fasting on macular microcirculation: an optical coherence tomography angiography study

2019 ◽  
Vol 104 (8) ◽  
pp. 1098-1102
Author(s):  
Yalçın Karaküçük ◽  
Abdullah Beyoglu ◽  
Ayşegül Çömez
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Ophthalmological Examination ◽  
Optical Coherence ◽  
Flow Area ◽  
Fasting Period ◽  
Avascular Zone ◽  
The Mean

AimTo analyse the effect of fasting on the retinal vascular plexus and choriocapillaris structures in healthy subjects via Optical Coherence Tomography Angiography (OCTA).MethodsIn this prospective study, OCTA scans of 98 eyes in 49 healthy subjects were compared in fasting and non-fasting period. All cases had a full ophthalmological examination, with OCTA parameters measured, including superficial flow area (SCP) (mm2), deep flow area (DCP) (mm2), choriocapillaris flow area (CC) (mm2), superficial and deep vascular density (SVD and DVD, respectively) (%), superficial foveal avascular zone area (FAZs) (mm2), deep foveal avascular zone area (FAZd) (mm2), subfoveal choroidal thickness (SFCT) (µm) and central macular thickness (CMT) (µm).ResultsThe mean SCP, DCP and CC flow area values were induced to be significantly lower in a fasting than a non-fasting period (p<0.001, p<0.001, p=0.049, respectively). The mean VD in a fasting period was statistically significantly lower than in a non-fasting period at the SCP level (p=0.009). No statistically significant difference was found between the two periods in respect to DVD, FAZd and CMT (p=0.068, p=0.653 and p=0.531, respectively); however, FAZs were significantly lower in a non-fasting than fasting period (p=0.038). The SFCT was determined to be statistically significant and thicker during a fasting period (p<0.001).ConclusionThe current study documented several physiological changes in a fasting period, such as changes in SCP, DCP, CC flow, SVD and DVD, via OCTA.

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