scholarly journals Foveal Avascular Zone in Hypertension as Measured by Optical Coherence Tomography Angiography

2019 ◽  
pp. 131-135
Author(s):  
Ludmila Gomes Dantas De Sá ◽  
Diego Nery Benevides Gadelha ◽  
Maria Cecília Santos Cavalcanti Melo ◽  
Carlos Teixeira Brandt
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Study Group ◽  
Optical Coherence ◽  
Control Groups ◽  
Hypertensive Patients ◽  
Avascular Zone ◽  
The Right ◽  
And Control

Purpose: To investigate the Foveal Avascular Zone (FAZ) area in patients with arterial hypertension using optical coherence tomography angiography (OCT-A).Material and methods: The study was permormed at the School Clinic of UNIFACISA and at the Eye Care Center. It was included 21 hypertensive patients (study group) and 19 individuals without hypertension (control group). It was excluded patientes with diabetes or glaucoma. The measurement of the FAZ areas was performed by the DRI OCT-1Triton/Plus. For the quantitative variables, the results were expressed by their means and standard deviations. Qualitative variables were expressed by their absolute and relative frequencies. Student’s t-test was used to verify differences between means and Fisher’s exact test for differences between frequencies. For evaluating the correlation between the superficial and deep plexus areas, the Pearson correlation test was used. P value ≤ 0.05, rejected the null hypothesis. The research was approved by the Ethics Committee of the Medical School from Campina Grande -UNIFACISA and all individuals signed the free and informed consent form.Results: The means of the superficial FAZ of both eyes was significantly higher in the study group (right eye 410.7 ± 160.7 μm2 - 319.1 ± 108.2 μm2 - p = 0.0433); (left eye: 405.4 ± 144.8 μm2 versus 309.4 ± 87.7 μm2- p = 0.0174). The means of the deep FAZ areas of the right and left eyes were similar between the study and control groups (right eye: 559.6 ± 253.28 μm2 versus 605.1 ± 226.8 μm2 - p = 0.5548); (left eye: 673.2 ± 170.8 μm2 versus 585.6 ± 171.2 μm2 - p = 0.1142). The relationships between the superficial and deep plexus areas of both eyes showed a weak correlation between the two plexuses. (r = 0.4734), left eye (r = 0.2287), study group - right eye: (r = 0.4374), left eye (r = 0.3580).Conclusion: The area of superficial FAZ of the right and left eyes was significantly higher in the hypertensive patients. The deep FAZ area of both eyes, however showed similar mean areas between the study and control groups.

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 949. Use of Optical Coherence Tomography Angiography to Assess Microvascular Health Among Persons with HIV: Employing the Retina as a Convenient Window

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S507-S507
Author(s):  
Lauren F Collins ◽  
Jessica G Shantha ◽  
Peter L Nesper ◽  
Anandi N Sheth ◽  
Amani A Fawzi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Retinal Vasculitis ◽  
Organ Damage ◽  
Screening Tools ◽  
Foveal Avascular Zone ◽  
Invasive Technique ◽  
Optical Coherence ◽  
Hiv Diagnosis ◽  
The Right

Abstract Background Mechanisms underlying the rising burden of non-AIDS comorbidities (NACM) among persons with HIV (PWH) remain unclear. Microvasculopathy may link HIV-related chronic inflammation and premature multimorbidity, similar to diabetes and other conditions characterized by inflammatory end-organ damage. We used a novel retinovascular imaging tool, optical coherence tomography angiography (OCTA), to evaluate the retina as a convenient assessment of microvascular health among PWH. Methods Data from 4 PWH who underwent OCTA (Zeiss CIRRUSTM HD-OCT 5000) at the Emory Eye Center from 2018-2020 were analyzed. Demographics, HIV-specific indices and NACM were summarized at the time of OCTA. Images were reviewed qualitatively and metrics of microvascular health – the foveal avascular zone (FAZ) area and vessel density (VD) from the superficial capillary plexus (SCP) – were calculated by ImageJ. Results The median age was 39 years, 100% were male, 100% were black, 25% had ever smoked, and median body mass index was 25.4 kg/m2. Median time since HIV diagnosis was 19 years, all patients had a history of clinical AIDS, including 2 with prior cytomegalovirus retinitis. Median current CD4 count was 84 cells/mm3, 100% were prescribed antiretroviral therapy and 50% had HIV viral suppression. Prevalent NACM included (each n=1): hypertension, dyslipidemia, diabetes, chronic kidney disease and asthma. Qualitatively, all 7 of the eyes evaluated by OCTA had evidence of microvascular pathology: 2 eyes demonstrated diffuse capillary nonperfusion, while the remaining 5 eyes had focal areas of nonperfusion around the FAZ. Mean FAZ area was 0.31 (SD±0.10) mm2 and mean VD of the SCP was 43.9% (SD±10.9%). Retinovascular pathology identified by fundoscopy and OCTA is shown in the figure. Figure. Retinal imaging of a PWH with bilateral retinal vasculitis. Fundus photos of the right (A) and left (C) eyes show retinal vasculitis highlighted by the red arrows. OCTA of the right (B) and left (D) maculae (3X3 scan Zeiss AngioplexTM) show the FAZ areas outlined in yellow, both of irregular contour. OCTA of the left macula demonstrates areas of significant flow voids marked by the asterisks and the FAZ area is enlarged. Conclusion Among patients with longstanding HIV, OCTA identified microvascular abnormalities in all retinae examined. Retinovascular evaluation by OCTA is a feasible, non-invasive technique for assessing microvascular health and findings support additional study in a larger, more diverse group of PWH. Screening tools targeting microvasculopathy among PWH may aid in earlier detection of those at greatest risk of NACM and allow for aggressive risk-modification strategies. Disclosures All Authors: No reported disclosures

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.

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