Role Of Optical Coherence Tomography Angiography Research Articles

Application and research progress of optical coherence tomography angiography in central nervous system diseases

Optical coherence tomography angiography (OCTA) is a new vascular imaging technology based on high-resolution optical coherence tomography image analysis. It can scan the moving red blood cells in blood vessels for three-dimensional imaging of human retinal and choroidal vessels. Since the close connection of vascular endothelial cells of the blood-retinal barrier is similar to that of the blood-brain barrier, the role of OCTA in the research of pathogenesis and course monitoring of a variety of central system diseases such as Alzheimer's disease, Parkinson's disease, stroke, migraine, multiple sclerosis and optic neuromyelitis has been widely discussed. This article reviews the application and progress of OCTA in central nervous system diseases.

Contribution of optical coherence tomography angiography OCT-A in diabetic maculopathy

IntroductionDiabetic retinopathy (DR) increases the risk of blindness by 25 times. Advanced researchs are justified for better management, leading to the role of Optical Coherence Tomography-Angiography (OCT-A), a new non-invasive imaging technique exploring retinal vascularization.Our purpose is to identify microvascular macular anomalies of DR on OCT-A with qualitative and quantitative evaluation of their impact on retinal vascularization. Patients and methodsThis is a descriptive cross-sectional study where 120 eyes of 66 diabetic patients were enrolled. All patients were diabetic and went through OCT-A imaging. ResultsMicroanevrysms were identified in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) where they were more frequently visualized. Macular edema was present in 16,7% of cases in the SCP, and in 30% in DCP. Edema spaces were more frequently present in DCP (p < 0,05). Capillary nonperfusion areas were identified in 82,5% of cases in SCP and in 60% of cases in DCP. The main peri-foveal vascular density was 18,95 ± 5,37%. The main surface of foveal avascular zone (FAZ) in the SCP was 462,52 μm2 and was 555,04 ± 329,11 μm2 in the DCP where it was larger. ConclusionOCT-A is a modern imaging tool that could be used for the diagnosis and monitoring of DR as well as the understanding of its pathophysiology.

The Role of OCT Angiography in the Assessment of Epiretinal Macular Membrane.

Background The aim of this observational study is to assess pre- and postoperative retinochoroidal vascular changes in patients undergoing epiretinal macular membrane (ERM) surgery by using optical coherence tomography angiography (OCTA). Materials and Methods 23 eyes affected by ERM and those which underwent phacovitrectomy associated with ERM peeling were enrolled. They were evaluated using structural OCT and OCTA before surgery and at 1, 3, and 6 months postoperatively. Results We found a statistically significant (p < 0.05) increase in the superficial capillary plexus vessel density (VD) from baseline to the 6-month follow-up. We observed a large increase in both the perfusion density (PD) and the VD of the deep capillary plexus between baseline and the 6-month follow-up (p < 0.001). A significant decrease in the VD and PD of the choriocapillaris (CC) from baseline to the 1st month and a significant increase in CC perfusion density at the 6-month follow-up compared to the preoperative value were revealed. The FAZ area and perimeter after surgery significantly increased during the follow-up (p < 0.001) at baseline retinal and choroidal plexi with a lower PD or VD correlated with worse visual acuity (p < 0.05 for all plexi). At baseline and at the 1-month follow-up, a significant correlation was found with the FAZ area and the FAZ perimeter: a smaller FAZ area or a smaller FAZ perimeter was correlated to a lower visual acuity. Before surgery, negative correlations (p < 0.05) were found between the Govetto ERM stages and perfusion density of the SCP and the DCP and between the Govetto stages and vessel density of the DCP. Conclusions In our study, OCTA detected vascular alterations induced by the presence of the ERM, allowing several correlations with functional data. In these patients, OCTA may be useful to add new potential surgical prognostic factors.

Commentary: Role of optical coherence tomography-angiography in diabetes mellitus: Utility in diabetic retinopathy and a comparison with fluorescein angiography in vision threatening diabetic retinopathy

Commentary: Role of optical coherence tomography-angiography in diabetes mellitus: Utility in diabetic retinopathy and a comparison with fluorescein angiography in vision threatening diabetic retinopathy

Role of optical coherence tomography-angiography in diabetes mellitus: Utility in diabetic retinopathy and a comparison with fluorescein angiography in vision threatening diabetic retinopathy.

Purpose:To determine the utility of optical coherence tomography-angiography (OCT-A) in diabetic retinopathy (DR) and comparison versus fluorescein angiography (FA) in vision-threatening diabetic retinopathy (VTDR).Methods:In this cross-sectional observational study, 60 eyes with no DR (NDR), 60 eyes with non-proliferative diabetic retinopathy (NPDR), and 60 eyes with proliferative diabetic retinopathy (PDR) underwent OCT-A. FA was done in VTDR. OCT-A of the NDR eyes was analyzed by two independent retina specialists. Vessel density (VD) (mm/mm2), perfusion density (PD) (%), and foveal avascular zone (FAZ) (mm2) area was analyzed among the groups. Montage angiography with vitreoretinal interface (VRI) segmentation was done in PDR. A qualitative comparison was done between OCT-A and FA for features of DR.Results:OCT-A detected 16.66% of the eyes with microaneurysm and 57.5% of the patients with capillary non-perfusion (CNP) areas in the NDR group. The inter-grader coefficient between the two observers was 0.820 for microaneurysm and 0.880 for CNP. The mean VD in NDR, NPDR, and PDR was 16.865, 13.983, and 11.643 mm/mm2. The mean PD in NDR, NPDR, and PDR was 30.595, 26.853, and 23.193%. The VD and PD values were statistically significant (P < 0.001). The mean FAZ area was not statistically significant (NPDR and PDR) (P > 0.05). The VRI showed elevated neovascularization in four eyes. OCT-A delineated microaneurysm and FAZ in 97/97 eyes who underwent FA. The FA failed to delineate FAZ in 2/37 NPDR eyes and 13/60 PDR eyes. The CNP areas (OCT-A) were detectable in all eyes. The FA demonstrated CNP areas in 17/37 and 36/60 eyes in NPDR and PDR, respectively. The FA could show peripheral CNP.Conclusion:The OCT-A helps in the early diagnosis of DR by providing vascular indices which are consistent with disease progression. OCT-A is non-invasive and ideal for follow-up. FA is a dynamic test with a larger field of view.

Early vascular modifications after endoscopic endonasal pituitary surgery: The role of OCT-angiography.

PurposeThe aim of the present study is to analyze the changes in retinal vessel density (VD), using Optical Coherence Tomography Angiography (OCT-A), in patients that received endoscopic endonasal approach for the removal of an intra-suprasellar pituitary adenoma compressing optic chiasm.MethodsWe evaluated the VD in Superficial Capillary Plexus (SCP), Deep Capillary Plexus (DCP), Radial Peripapillary Capillary (RPC) and the Foveal Avascular Zone (FAZ) area in a series of fourteen patients (7 males, 7 females, mean age 56 ± 13 years), as compared to healthy controls. We also detected the structural Spectral Domain (SD)-OCT parameters: Ganglion Cell Complex (GCC), Retinal Nerve Fiber Layer (RNFL), visual field parameters (Mean Deviation, Pattern Standard Deviation) and Best Corrected Visual Acuity (BCVA). These measurements were performed prior than surgery and 48 hours after.ResultsThe patients showed a significant decrease in VD of the macular and papillary regions, a significant increase in FAZ area, a significant impairment in SD-OCT, VF parameters and BCVA respect to 14 eyes of 14 healthy controls (p<0.05), at pre-op evaluation. In patients group the VD in SCP, DCP and RPC increased after surgery respect to baseline but the difference turned to be out statistically significant only in RPC (p = 0.003). Also the BCVA (p = 0.040) and the Mean Deviation at visual field (p = 0.015) significantly improved after surgery. While there was a reduction in structural OCT parameters but it was statistically significant only in GCC (p = 0.039). A positive correlation was found between the preoperative VD of the RPC, Mean Deviation, BCVA and the postoperative Mean Deviation (r = 0.426 p = 0.027; r = 0.624 p = 0.001; r = 0.515 p = 0.006).ConclusionOCT-A allows to detect the early changes occurring within 48 hours after surgery showing that the improvement in retinal vessel density could occur before the recovery of the structural OCT parameters and can be a positive predictive factor for the functional recovery.

The role of OCT angiography in a study of retinal perfusion after endovitreal intervention due to rhegmatogenous retinal detachment.

Annotation&#x0D; Relevance: OCT angiography is a non-invasive method of qualitative and quantitative analysis of the retinal perfusion. After rhegmatogenous retinal detachment and vitrectomy with endotamponade the retinal perfusion changes.&#x0D; Aim: To analyze the data from clinical studies that evaluate changes in blood microcirculation of the retina and choroid, visual acuity effects after vitrectomy with endotamponade due to rhegmatogenous retinal detachment by OCTA&#x0D; Materials and methods: A literature search was conducted using PubMed, Cochrane Library, and Embase until April 2020.&#x0D; Results and conclusions: This literature review describes modern ideas about the structure of the normal retinal vascular plexuses, analyzes the results of clinical studies that evaluate retinal perfusion changes after vitrectomy due to rhegmatogenous retinal detachment according to OCTA.&#x0D; erials and methods: A literature search was conducted using PubMed, Cochrane Library, and Embase until April 2020.&#x0D; Results and conclusions: This literature review describes modern ideas about the structure of the normal retinal vascular plexuses, analyzes the results of clinical studies that evaluate retinal perfusion changes after vitrectomy due to rhegmatogenous retinal detachment according to OCTA.

Role of Optical Coherence Tomography Angiography in the Diagnosis and Management of Wet Age-Related Macular Degeneration

Abstract Background Neo-vascular age-related macular degeneration (nAMD) (an advanced form of macular degeneration) is the main cause of visual impairment in older adults related to AMD. WHO has estimated that approximately 8 million people will be affected by AMD by the year 2020. Optical coherence tomography angiography (OCTA) is a novel imaging modality that permits direct visualization of the retinal and choroidal vasculature in vivo. In OCTA, high-frequency and dense volumetric scanning are made to detect blood flow by analyzing the signal decorrelation between scans. Compared with stationary areas of the retina, the movement of erythrocytes within a vessel makes a decorrelated signal. Unlike traditional angiography, OCTA does not necessitate the use of exogenous dyes, so avoiding potential side effects, such as nausea or other more serious adverse events. However, the role of OCTA as a diagnostic tool has not been largely investigated. Particularly, very few clinical studies have assessed the accuracy of OCTA imaging for the diagnosis of nAMD. Aim of the Work To highlight the benefits of using OCT-A in the diagnosis and management of wet AMD and compare it with the conventional angiographic standard, fundus fluorescein angiography (FFA). Subjects and Methods An interventional prospective comparative study will be conducted on 40 eyes diagnosed with wet AMD. Optical coherence tomography angiography and FFA will be done for all eyes. Analysis of the data obtained from the OCT-A will be done and compared with the standard FFA. Conclusion AMD is the leading cause of vision loss. Early detection and treatment is required. AMD is diagnosed by fundus examination, FA, and OCTA. OCTA and FA imaging provide complementary information about pathological changes in chorioretinal diseases. OCTA is highly sensitive for identifying AMD, CNV, and CNV activity; however, it cannot fully replace FA in the diagnosis of AMD.

Роль ОКТ-ангиографии в определении показаний к антиангиогенной терапии пациентов со сливными друзами

Роль ОКТ-ангиографии в определении показаний к антиангиогенной терапии пациентов со сливными друзами

Multimodal imaging of diabetic retinopathy, the role of OCT angiography

Multimodal imaging of diabetic retinopathy, the role of OCT angiography

Role of OCT Angiography in the Detection of Retinal Vascular and Macular Abnormalities in Subjects with Asteroid Hyalosis

ABSTRACT Purpose: To study the role of Optical coherence tomography (OCT) Angiography (OCTA) in detecting retinal vascular and macular abnormalities as compared to Fundus Fluorescein Angiography (FFA) in subjects with Asteroid hyalosis (AH). Methods: In a prospective study, patients with AH underwent OCTA and FFA. AH graded as Grade 1 in 8 (optic disc, second order vessels visible), Grade 2 in 4 (optic disc, first-order vessels visible), Grade 3 in 11 (hazy view of optic disc) and Grade 4 (no view of fundus) in 2 eyes. Results: A total of 20 patients (25 eyes) with AH were included. In comparison to FFA, OCTA was able to similarly detect Diabetic Retinopathy changes such as Neovascularization, microaneurysms, capillary dropout, and foveal avascular zone extent in vascular occlusion in all grades of AH. Conclusion: OCTA, a noninvasive imaging tool, could detect various retinal vascular and macular abnormalities in patients with all grades of AH in comparison to FFA.

Extreme Hyperglycemia Causes Vascular Hypoperfusion at Optic Nerve Head in Diabetic Patients (DM)

Background: OCT angiography (OCTA) and laser speckle flowgraphy (LSFG) are novel and noninvasive imaging modalities which could evaluate fundus blood flow quantitatively. However, the role of OCTA and LSFG as diagnostic tools has not been widely investigated. Previous reports indicated that NO, reduced by hyperglycemia, exerts a key role for the autoregulation of retinal blood flow. We designed this study to evaluate the retinal blood flow by OCTA and LSFG in hyperglycemic DM. Method: 10 patients with extreme hyperglycemia at our outpatient clinic (FPG&amp;gt;250mg/dL, or casual PG&amp;gt;350mg/dL, age 58±5, 7 males, HbA1c 11.1±0.5%) and 32 healthy volunteers (age 48±2, 17 males) were included. Vascular density was calculated using OCTA. LSFG measured relative blood velocity (mean blur rate: MBR) in the optic nerve head (ONH). MBR-A (the mean of all area), MBR-V (the vessel mean) and MBR-T (the tissue mean) were analyzed. Result: OCTA revealed no difference between two groups in the vascular density at macula (47.37±1.14% for DM and 47.44±0.67% for NDM) and a tendency of decrease in the diabetic vascular density at ONH (40.14±3.56% for DM and 42.48±1.25% for NDM) without statistical significance. With LSFG, MBR-A and MBR-T did not exhibit significant differences, while MBR-V significantly decreased in DM compared to the healthy (42.85±2.05% for DM, 49.25±1.34% for NDM, p = 0.025). Discussion: Our results demonstrated that vascular hypoperfusion at ONH was associated with extreme hyperglycemia in DM with tendency to decrease in vascular density. It is generally supposed that the retinal blood flow decreases in DM and acute hyperglycemia. In DM actually presented physiological changes in the retina. Besides, there is a report that autoregulation of blood flow in the ONH is disrupted in diabetic rabbits, as well as in healthy ones with uncoupled gap junctions. It is possible that the similar mechanisms are involved in ONH blood flow decrease observed in this study. Disclosure T. Mitsumatsu: None. F. Yagi: None. Y. Kondo: None. A. Anraku: None. S. Okahata: None. K. Sakamoto: None. G. Tomita: None. T. Shiba: Speaker's Bureau; Self; Shionogi &amp; Co., Ltd., Pfizer Inc., Merck Sharp &amp; Dohme Corp., Kowa Company, Ltd., Daiichi Sankyo Company, Limited.

Optical Coherence Tomography Angiography in Retinal Vein Occlusion: Quantifying Macular Ischemia

Optical coherence tomography angiography (OCTA) is a new imaging modality that has the ability to image the retinal vasculature without the use of intravenous dye. This review aims to explore the role of OCTA when used to measure macular ischemia in patients with retinal vein occlusion (RVO). OCTA and fluorescein angiography are highly correlated in their findings related to macular perfusion status in patients with RVO. OCTA is able to quantify changes in macular perfusion following anti-VEGF treatment. Macular ischemia quantified using OCTA correlates with visual function. Studies to date are limited by small patient numbers and retrospective study design. Despite this, there is evidence that for patients with RVO, OCTA is able to quantify macular ischemia with the added advantage of measuring non-perfusion area in the deep capillary plexus. The high correlation of macular perfusion with macular sensitivity suggests future prognostic potential.

Foveal Avascular Zone in Normal Tension Glaucoma Measured by Optical Coherence Tomography Angiography.

Aim To measure diameter of foveal avascular zone (FAZ), FAZ area, and vessel density using Optical Coherence Tomography Angiography (OCT-A) in patients with normal tension glaucoma (NTG) and to establish the possible role of OCT-A in diagnosis and follow-up of patients with NTG. Methods Twenty-one eyes of 21 patients with NTG and 30 eyes of 30 healthy subjects underwent complete ophthalmic examination as well as OCT-A on ZEISS AngioPlex. 3 × 3 macula scans were used to measure vertical, horizontal, and maximum diameter of FAZ by two graders. Mean values and interobserver variability were analyzed. Image J was used for analysis of FAZ area and vessel density. Results Mean vertical diameter (t = 5.58, p < 0.001), horizontal diameter (t = 3.59, p < 0.001), maximum diameter (t = 5.94, p < 0.001), and FAZ area (t = 5.76, p < 0.001) were statistically significantly enlarged in the NTG group compared to those in the control group. Vessel density (t = −5.80, p < 0.001) was statistically significantly decreased in the NTG group compared to that in the control group. Conclusion OCT-A could have an important role in the future in diagnosis of patients with NTG. In patients with NTG, there is larger FAZ area, while the vessel density is reduced in comparison to the control group.