scholarly journals Acircularity and circularity indexes of the foveal avascular zone in high myopia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helong Piao ◽  
Yue Guo ◽  
Haowei Zhang ◽  
Mi Sun Sung ◽  
Sang Woo Park
Keyword(s):  
Significant Variation ◽  
High Myopia ◽  
Optical Coherence Tomography Angiography ◽  
Major Axis ◽  
Minor Axis ◽  
Foveal Avascular Zone ◽  
Strongly Correlated ◽  
Regression Analyses ◽  
Lower Quartile ◽  
Avascular Zone

AbstractThis study explored the association between foveal avascular zone (FAZ) parameters and high myopia using optical coherence tomography angiography. We divided 106 eyes of 106 patients into quartiles based on the axial length. The upper quartile was then defined as the high myopia group (n = 27), while the lower quartile was the non-high myopia group (n = 26). The areas and minor axis lengths of superficial and deep FAZ, the perimeters and major axis lengths of deep FAZ were significantly larger in eyes with high myopia than in eyes with non-high myopia (P < 0.05). Inversely, the subfoveal choroidal thickness was significantly thinner in eyes with high myopia than in those with non-high myopia. Linear regression analyses showed that no significant correlation was observed between FAZ areas and acircularity and circularity indexes of FAZ in non-high myopia group. Conversely, FAZ areas strongly correlated with acircularity and circularity indexes of FAZ in high myopia group. We found that an increase in the FAZ area in highly myopic eyes was accompanied by a significant variation in FAZ acircularity and circularity indexes. Further research should address whether these findings are associated with future disease development in highly myopic eyes.

scholarly journals Acircularity and Circularity Indexes of the Foveal Avascular Zone in High Myopia

2021 ◽  
Author(s):  
Helong Piao ◽  
Yue Guo ◽  
Haowei Zhang ◽  
Mi Sun Sung ◽  
Sang Woo Park
Keyword(s):  
Axial Length ◽  
High Myopia ◽  
Major Axis ◽  
Foveal Avascular Zone ◽  
Strongly Correlated ◽  
Circularity Index ◽  
Avascular Zone ◽  
The Mean ◽  
Size And Morphology ◽  
Specific Influence

Abstract We explored the association between foveal avascular zone (FAZ) parameters and high myopia using optical coherence tomography angiography (OCTA). To evaluate the specific influence of high myopia on the FAZ, we divided 106 eyes of 106 patients into quartiles based on the axial length. The upper quartile was then defined as the high myopia group (n = 27), while the lower quartile was the non-high myopia group (n = 26). The FAZ parameters of these two groups were then retrospectively compared to investigate variations in FAZ size and morphology. The mean axial length and spherical equivalent were 23.96 ± 0.94 mm and -2.27 ± 1.58 diopters in the non-high myopia group and 27.42 ± 0.36 mm and -8.12 ± 2.14 diopters in the high myopia group, respectively. The areas of superficial and deep FAZ, perimeters of deep FAZ, major axis lengths of deep FAZ, minor axis lengths of superficial and deep FAZ were significantly larger in eyes with high myopia than in eyes with non-high myopia (P < 0.05). Linear regression analyses showed that no significant correlation was observed between FAZ areas and acircularity and circularity index of FAZ in non-high myopia group, conversely, FAZ areas strongly correlated with acircularity and circularity index of FAZ in high myopia group. We found that An increase in the FAZ area in highly myopic eyes was accompanied by a significant variation in FAZ acircularity and circularity indexes. Further research should address whether these findings are associated with future disease development in highly myopic eyes.

scholarly journals Is the Retinal Vasculature Related to β-Peripapillary Atrophy in Nonpathological High Myopia? An Optical Coherence Tomography Angiography Study in Chinese Adults

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jiao Sun ◽  
Jialin Wang ◽  
Ran You ◽  
Yanling Wang
Keyword(s):  
Optical Coherence Tomography ◽  
High Myopia ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
Foveal Avascular Zone ◽  
Vascular Density ◽  
Retinal Vasculature ◽  
Optical Coherence ◽  
Peripapillary Atrophy ◽  
Avascular Zone

Purpose. The association between β-peripapillary atrophy and the retinal vasculature in nonpathological high myopia is unclear. The aim of this study is to investigate whether β-peripapillary atrophy contribute to the changes of the retinal vasculature using optical coherence tomography angiography. Methods. In a cross-sectional study, one hundred and thirty eyes with nonpathological high myopia were included. β-peripapillary atrophy was analysed using Image J software based on fundus photographs. A 3.0 × 3.0 mm2 grid and a 4.5 × 4.5 mm2 grid were used to scan parafoveal and peripapillary regions using optical coherence tomography angiography, respectively. Vessel density and fractal dimensions of the retina and foveal avascular zone were analysed and quantified using en face projection images. Correlations between the vascular density, foveal avascular zone, and β-peripapillary atrophy were determined. Results. Using multivariate analysis, β-peripapillary atrophy was negatively correlated with the vessel density in radial peripapillary capillaries (p=0.002) even after adjusting for other variables. This relationship was also confirmed in the macula (superficial retinal plexus: p<0.05; deep retinal plexus: p<0.05). The vessel densities in the nasal and inferior sectors were more strongly correlated with β-peripapillary atrophy. Conclusions. There was a negative correlation between β-peripapillary atrophy and the retinal vasculature in highly myopic eyes, especially in radial peripapillary capillaries and deep retinal plexus. β-peripapillary atrophy can be visualized and is a convenient structural feature that can benefit the early diagnosis and detection of chorioretinal atrophy in high myopia.

scholarly journals Macular Vessel Density, Perfusion Density, Foveal Avascular Zone in Emmetropia and Myopia: Quantitative Assessment Using Optical Coherence Tomography Angiography

2019 ◽  
Author(s):  
XM Jiang ◽  
C Zheng ◽  
Q Tan ◽  
FF Du ◽  
M Zhou
Keyword(s):  
Optical Coherence Tomography ◽  
High Myopia ◽  
Optical Coherence Tomography Angiography ◽  
Statistical Significance ◽  
Vessel Density ◽  
Foveal Avascular Zone ◽  
Avascular Zone ◽  
Temporal Quadrant ◽  
Perfusion Density ◽  
Inferior Quadrant

Abstract Background To assess vessel density, perfusion density among emmetropic and myopic person, and to demonstrate detailed changes in superficial retinal microvascular network. Methods This was a single-centered, cross-sectional study of 120 participants. Emmetropic, low, moderate and high myopic group each account for 1/4. Enface 3mmx3mm optical coherence tomography angiography images were obtained using Cirrus™ HD-OCT 5000. Quantifiable measure of vessel density, perfusion density and foveal avascular zone were performed by AngioVue software. Results Gender, age, SBP, DBP, MOPP and IOP showed no differences among emmetropic and myopic groups. In inferior quadrant, vessel density and perfusion density of emmetropic and low myopia group showed statistical significance from moderate and high myopia group (all P<0.05). In temporal quadrant, vessel density and perfusion density of emmetropic, low and moderate myopia group showed statistical significance from high myopia group (all P<0.05).In emmetropic group, vessel density and perfusion density showed no difference among superior, inferior, temporal and nasal quadrants. In low myopic group, vessel density and perfusion density of temporal quadrant showed statistical significance from superior, inferior and nasal quadrants (all P<0.05). In moderate and high myopic group, vessel density and perfusion density of superior quadrant showed statistical significance from temporal quadrant (all P<0.05) and inferior quadrant(all P<0.05) . And vessel density of nasal quadrant showed statistical significance from inferior quadrant in moderate myopic group(P=0.039) . Conclusion Along with the increase of myopia degree, vessel density and perfusion density of inferior and temporal quadrants showed a statistically significant tendency of decrease. Vessel density and perfusion density of nasal quadrant showed a relatively decreasing tendency. Closer attention should be paid to moderate myopia.

Foveal avascular zone in oculocutaneous albinism

2021 ◽  
Vol 14 (5) ◽  
pp. e240208
Author(s):  
Hana A Mansour ◽  
Sami Uwaydat ◽  
Muhamad H Yunis ◽  
Ahmad M Mansour
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Oculocutaneous Albinism ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Retinal Capillary ◽  
Avascular Zone ◽  
Capillary Plexus ◽  
Foveal Hypoplasia

Optical coherence tomography angiography imaging in two patients with oculocutaneous albinism, one with severe nystagmus, showed persistence of both the superficial and the deep retinal capillary plexus adding another vascular feature to the foveal hypoplasia.

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 Glaucomatous Macular Vasculature: A Quantitative Analysis

2020 ◽  
Vol 9 (3) ◽  
pp. 185-197
Author(s):  
Pedro Arede ◽  
Joanna Przezdziecka-Dolyk ◽  
Fabian Debowy ◽  
Jacek Olszewski ◽  
Carla Fernandes ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Structural Changes ◽  
Open Angle Glaucoma ◽  
Major Axis ◽  
Foveal Avascular Zone ◽  
Control Group ◽  
Equivalent Diameter ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Avascular Zone

Background: The aim of this study was to evaluate the characteristics of the macular vessel density (VD) and the foveal avascular zone (FAZ) in glaucoma quantitatively using the optical coherence tomography angiography (OCT-A). Methods: Twenty-five eyes of 13 patients with primary open angle glaucoma (POAG) and 12 eyes of 6 healthy participants were enrolled retrospectively. Functional visual field (VF) and structural Spectral-Domain optical coherence tomography (SD-OCT) Retinal Nerve Fiber Layer Thickness (RNFLT) were assessed in all participants. OCT-A was performed on a fovea centered, 15x10 degrees, macular region. OCT-A scans were processed with MATLAB software and automatically graded to define FAZ parameters. The parafoveal VD in the superficial and deep retinal vascular plexus (SVP and DVP) was analyzed by quadrant and circular segmented zones. Results: Foveal Avascular Zone -Major Axis Length (p=0.02), Area (p=0.04), Equivalent Diameter (p=0.04) and Perimeter (p=0.04) were significantly larger in glaucoma than the control group. Regarding SVP and DVP, the average macular total VD were lower in glaucoma patients compared to the control group (p<0.01; p<0.01). Additionally, the inner circular region (p=0.04; p<0.01 respectively for SVP and DVP) and all quadrants except for North had a lower VD in glaucoma group compared to the control group. Assessment of the total VD successfully predicted RNFLT (p<0.001) and was significantly associated with the probability of glaucoma (p=0.009). Conclusion: OCT-A parameters, namely the FAZ morphology and the macular VD, were associated with glaucomatous functional and structural changes. The macular VD showed a considerable diagnostic value. It may be a modern biomarker, representing microvascular network disruption of the macular perfusion in glaucoma.

Sign in / Sign up

Export Citation Format

Share Document