Reproducibility and Repeatability of Foveal Avascular Zone Area Measurements Using Swept-Source Optical Coherence Tomography Angiography in Healthy Subjects

2016 ◽  
Vol 27 (3) ◽  
pp. 336-341 ◽  
Author(s):  
Rodolfo Mastropasqua ◽  
Lisa Toto ◽  
Peter A. Mattei ◽  
Marta Di Nicola ◽  
Isaia A.L. Zecca ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Swept Source ◽  
Avascular Zone ◽  
Within Subjects

Purpose To assess the reproducibility and repeatability of foveal avascular zone (FAZ) area measurements using swept-source optical coherence tomography angiography (SS-OCTA) in healthy subjects. Methods Sixty-four eyes of 64 healthy volunteers were randomly subjected to FAZ area measurements using SS-OCTA by 2 examiners in 2 different sessions. Results The FAZ areas measured by the first and second observer were 0.269 ± 0.092 mm2 and 0.270 ± 0.090 mm2, respectively. Within subjects, the coefficients of variations were 2.44% (95% confidence interval [CI] 1.95% to 2.93%) and 2.66% (95% CI 2.00% to 3.31%) for the first and second observers, respectively. The coefficient of repeatability average measurements of FAZ area were 0.021 mm2 and 0.024 mm2. The intraclass correlation coefficient values were 0.993 (95% CI 0.989 to 0.996) and 0.991 (95% CI 0.986 to 0.995). Interobserver and intraobserver concordance correlation coefficients ranged from 0.998 (95% CI 0.997 to 0.999) to 0.999 (95% CI 0.998 to 0.999) and from 0.989 (95% CI 0.982 to 0.993) to 0.987 (95% CI 0.979 to 0.992), respectively. Conclusions The FAZ area measurements by means of SS-OCTA showed high reproducibility and repeatability in healthy eyes.

scholarly journals Automatic segmentation of foveal avascular zone based on adaptive watershed algorithm in retinal optical coherence tomography angiography images

2021 ◽  
Author(s):  
Jian Liu ◽  
Shixin Yan ◽  
Nan Lu ◽  
Dongni Yang ◽  
Chunhui Fan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Automatic Segmentation ◽  
Qualitative Evaluation ◽  
Foveal Avascular Zone ◽  
Watershed Algorithm ◽  
Strong Positive Correlation ◽  
Optical Coherence ◽  
Avascular Zone

The size and shape of the foveal avascular zone (FAZ) have a strong positive correlation with several vision-threatening retinovascular diseases. The identification, segmentation and analysis of FAZ are of great significance to clinical diagnosis and treatment. We presented an adaptive watershed algorithm to automatically extract FAZ from retinal optical coherence tomography angiography (OCTA) images. For the traditional watershed algorithm, “over-segmentation” is the most common problem. FAZ is often incorrectly divided into multiple regions by redundant “dams”. This paper analyzed the relationship between the “dams” length and the maximum inscribed circle radius of FAZ, and proposed an adaptive watershed algorithm to solve the problem of “over-segmentation”. Here, 132 healthy retinal images and 50 diabetic retinopathy (DR) images were used to verify the accuracy and stability of the algorithm. Three ophthalmologists were invited to make quantitative and qualitative evaluations on the segmentation results of this algorithm. The quantitative evaluation results show that the correlation coefficients between the automatic and manual segmentation results are 0.945 (in healthy subjects) and 0.927 (in DR patients), respectively. For qualitative evaluation, the percentages of “perfect segmentation” (score of 3) and “good segmentation” (score of 2) are 99.4% (in healthy subjects) and 98.7% (in DR patients), respectively. This work promotes the application of watershed algorithm in FAZ segmentation, making it a useful tool for analyzing and diagnosing eye diseases.

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.

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).

Optical coherence tomography angiography reveals vascular alterations in pediatric commotio retinae

2020 ◽  
pp. 112067212092461 ◽  
Author(s):  
Eleni Papageorgiou ◽  
Nikolaos Voutsas ◽  
Maria Kotoula ◽  
Anna Dastiridou ◽  
Evangelia E Tsironi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Swept Source ◽  
Avascular Zone ◽  
Commotio Retinae

Introduction Aim of this study is to present the acute and long-term swept-source optical coherence tomography angiography findings in pediatric commotio retinae. Materials and methods Two children presented with reduced visual acuity and Berlin edema after blunt trauma. Results Swept-source optical coherence tomography revealed hyperreflectivity of the retinal nerve fiber layer and disruption of the ellipsoid zone and the retinal pigment epithelium. Swept-source optical coherence tomography angiography showed enlarged superficial foveal avascular zone in both cases. In the more severe case, there was enlargement of both superficial and deep foveal avascular zone, and reduction of the superficial vascular plexus density. Conclusion The present findings suggest that pediatric commotio retinae may be associated with retinal vascular changes, that is, foveal avascular zone enlargement and decreased vessel density. The extent of the microvascular alterations is possibly related to trauma severity.

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.

Intra- and Interdevice Deviation of Optical Coherence Tomography Angiography

2019 ◽  
Vol 236 (04) ◽  
pp. 551-554 ◽  
Author(s):  
Stefan Trachsler ◽  
Arthur Baston ◽  
Marcel Menke
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Swept Source ◽  
Significant Difference ◽  
Capillary Plexus ◽  
Swept Source Oct ◽  
Scan Modes

Abstract Purpose To compare 4 optical coherence tomography-angiography (OCT-A) devices for foveal avascular zone (FAZ) measurements in healthy subjects. Methods The central retinas of 24 eyes of 12 healthy subjects were scanned with 4 different OCT-A devices (Optovue RTVue-XR, Zeiss Cirrus 5000-HD-OCT, a prototype Spectralis OCT2, Heidelberg Engineering, and Topcon DRI-OCT Triton Swept-source OCT). For the Topcon, Zeiss, and Optovue devices, 3-mm and 6-mm scans were performed. The Heidelberg device only provided 4-mm scans. En-face OCT-A images of the superficial and deep capillary plexus of the macular area were generated. The FAZ areas were measured and compared. Results Twenty-four healthy eyes were included. OCT-A devices showed significant differences in FAZ measurements. The Zeiss OCT-A device measured the smallest values for foveal avascular area (mean 218.7 mm2), followed by the Optovue device (229.6 mm2), the Topcon device (239.3 mm2), and the Heidelberg device (250.4 mm2). Differences were statistically significant for following devices: Heidelberg versus Optovue (p < 0.001), Heidelberg versus Zeiss (p < 0.001), Topcon versus Zeiss (p < 0.001), and Optovue versus Zeiss (p = 0.046). For the Optovue device, FAZ measurements were significantly different between 3 mm (mean 220 mm2) and 6 mm (mean 239.3 mm2, p = 0.007) scans. All other devices showed no significant difference within scan modes. Conclusion Current OCT-A devices provide images that allow such measurements, but values showed significant differences between devices and, for the Optovue instrument, even within scan modes. The data for OCTA measurements cannot be transferred interchangeably between the devices. Therefore, a patient should always be measured with the same device.

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