Optical coherence tomography angiography application to pigmented iris: Could a new index quantify blood flow?

2021 ◽  
pp. 112067212110334
Author(s):  
Stefano Lucentini ◽  
Kengo Ikesugi ◽  
Francesco Bonsignore ◽  
Cecilia Acuti Martellucci ◽  
Masahiko Sugimoto ◽  
...  
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Dark Adaptation ◽  
Pupil Size ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Quantify Blood Flow ◽  
Group D

Purpose: To assess the blood flow and vascular visibility of irises in relation to pigmentation and pupil size, using an anterior segment optical coherence tomography angiography (OCTA). Materials and methods: This is a cross-sectional study. OCTA images were acquired in the nasal and temporal quadrants from a cohort of 30 healthy subjects in photopic (miosis) and scotopic (mydriasis) conditions. Patients were divided according to iris color (less pigmented: group L vs more pigmented: group D). Vascular parameters (vessel density (VD), vessel length density (VLD), fractal dimension (FD)) were applied and compared among groups L and D, location and different pupil status. A novel vascular index called Luminance Index (LI) was developed and applied in order to quantify vascular flow and evaluate its variation in photopic and scotopic conditions. Multivariable analyses were performed to evaluate possible predictors of VD and LI. Results: No differences were found for all vascular measurements (VD, VDL, FD, LI) between nasal and temporal quadrants. All vascular measurements were higher in group L than in group D ( p < 0.05), except for LI and FD in photopic condition. In group L, all vascular parameters increased ( p < 0.001) after dark adaptation. In group D, only LI increased after dark adaptation ( p < 0.001). Pigmentation and iris thickness were significantly associated with VD in scotopic and photopic conditions, and with LI only in scotopic condition. Conclusions: Pigmentation still remains a major issue for vascular visibility. Quantitative and qualitative vascular changes follow pupil size variation. LI could be a new surrogate to quantify blood flow.

scholarly journals Optical Coherence Tomography Angiography in Herpetic Leucoma

2021 ◽  
Author(s):  
Inês Almeida ◽  
Libânia Dias ◽  
Jeniffer Jesus ◽  
Inês Fonseca ◽  
Maria João Matias ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Central Area ◽  
Corneal Neovascularization ◽  
Cross Sectional Study ◽  
Clinical Findings ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Monitor Treatment Response

Abstract Background: Herpes simplex virus (HSV) keratitis remains a leading infectious cause of blindness worldwide. This study instends to investigate the potential of Optical Coherence Tomography Angiography (OCTA) device to image and describe quantitatively the vascularization in eyes diagnosed with herpetic leucoma and to discuss and review the usefulness of this technique in this pathology. Methods: A Cross-sectional study was made, including 17 eyes of 15 patients with leucoma secondary to herpetic keratitis. All eyes underwent anterior segment Slit-Lamp photography (SLP), and Optical Coherence Tomography Angiography (OCT) with en-face, b-scans and c-scans imaging. The vessel density (VD) was analyzed in the inferior, nasal and temporal corneal margin in all patients, and in the central area, in eyes with central corneal neovascularization (CoNV). The measurements were calculated after binarization with ImageJ software, using OCTA scans with 6x6 mm in a depth of 800 μm. Results: Patients included had a mean age 53.267±21.542 (years±SD). The mean total vessel area was 50.907±3.435%. VD was higher in the nasal quadrant (51.156±4.276) but there were no significant differences between the three analyzed areas (p=0.940). OCTA was able to identify abnormal vessels when SLP apparently showed no abnormal vessels; OCTA was able to distinguish between larger and smaller vessels even in central cornea; OCTA scans allowed the investigation of several corneal planes and the relation of them with clinical findings. Conclusions: OCTA can be useful in both qualitative and quantitative follow-up of patients and may become a non-invasive alternative to objectively monitor treatment response in eyes with corneal vascularization due to herpetic infection.

Comparison of anterior segment optical coherence tomography angiography systems for corneal vascularisation

2017 ◽  
Vol 102 (7) ◽  
pp. 873-877 ◽  
Author(s):  
Marcus Ang ◽  
Kavya Devarajan ◽  
Suchandrima Das ◽  
Tisha Stanzel ◽  
Anna Tan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Case Series ◽  
Vessel Density ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Density Measurements ◽  
Split Spectrum

AimTo newly describe a spectral-domain (SD) optical coherence tomography angiography (OCTA) for the cornea and directly compare two OCTA system scans of the same eyes with corneal vascularisation.MethodsCross-sectional, observational, comparative case series. We performed sequential OCTA scans (10 eyes of 10 subjects with corneal vascularisation,4 scans each eye) repeated using split-spectrum amplitude decorrelation algorithm angiography system (SSADA, AngioVue; Optovue Inc, USA) and SD OCTA (Angioscan; Nidek Co. Ltd, Japan) in the same region of interest. We analysed all scan images for repeatability, image quality and vessel density measurements and compared OCTA systems.ResultsWe obtained substantial interobserver repeatability in terms of image quality score (κ=0.86) for all 80 OCTA scans (median age 49 years, 50% women). The correlation was moderately good (r=0.721) when comparing vessel density measurements between OCTA systems, but greater in the SSADA compared with SD OCTA system (mean vessel density 20.3±4.9% vs 15.1±4.2%, respectively; p<0.001).ConclusionIn this pilot clinical study, we describe successful delineation of corneal vessels with substantial image quality using a new SD OCTA system. The vessel density measurements were greater using the SSADA compared with SD OCTA system in the same area of corneal vascularisation. Further studies are required to confirm the advantages, limitations and differences between these OCTA systems for the anterior segment.

scholarly journals Visualization of three-dimensional microcirculation of rodents’ retina and choroid for studies of critical illness using optical coherence tomography angiography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jang Ryul Park ◽  
ByungKun Lee ◽  
Min Ji Lee ◽  
Kyuseok Kim ◽  
Wang-Yuhl Oh
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Severe Sepsis ◽  
Critical Illness ◽  
Hemorrhagic Shock ◽  
Optical Coherence Tomography Angiography ◽  
Flow Index ◽  
Optical Coherence ◽  
Sepsis Model ◽  
Lactate Levels

AbstractWe developed a method to measure the relative blood flow speed using optical coherence tomography angiography (OCTA) in retina and choroid, and investigated the feasibility of this method for assessing microcirculatory function in rat models of sepsis and hemorrhagic shock. Two sepsis models, 6-h severe sepsis without treatment and 30-h moderate sepsis maintaining mean arterial pressure, and volume controlled hemorrhagic shock and fluid resuscitation model were used to see the change of microcirculation. The blood flow index (BFI), which was calculated from the OCTA images to represent the average relative blood flow, was decreasing during the 6-h severe sepsis model. Its change is in parallel with the mean arterial blood pressure (MAP) and blood lactate levels. In the 30-h moderate sepsis model, the BFI was decreased while maintaining MAP, and lactate was increased. In the hemorrhagic shock model, the change of BFI is in line with MAP and lactate levels. In all models, BFI change is more sensitive in choroid than in retina. This study presents the OCTA-based retinal and choroidal microcirculatory blood flow monitoring method and shows its utility for assessment of critical illness.

scholarly journals Comparison of swept-source versus spectral-domain optical coherence tomography angiography for detection of macular neovascularization

2021 ◽  
Author(s):  
Anna Lentzsch ◽  
Laura Schöllhorn ◽  
Christel Schnorr ◽  
Robert Siggel ◽  
Sandra Liakopoulos
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
En Face ◽  
Increased Sensitivity ◽  
Sensitivity Specificity ◽  
Subretinal Hyperreflective Material

Abstract Purpose To compare swept-source (SS) versus spectral-domain (SD) optical coherence tomography angiography (OCTA) for the detection of macular neovascularization (MNV). Methods In this prospective cohort study, 72 eyes of 54 patients with subretinal hyperreflective material (SHRM) and/or pigment epithelial detachment (PED) on OCT possibly corresponding to MNV in at least one eye were included. OCTA scans were acquired using two devices, the PLEX Elite 9000 SS-OCTA and the Spectralis SD-OCTA. Fluorescein angiography (FA) was used as reference. Two graders independently evaluated en face OCTA images using a preset slab as well as a manually modified slab, followed by a combination of en face and cross-sectional OCTA. Results Sensitivity (specificity) for the automated slabs was 51.7% (93.0%) for SS-OCTA versus 58.6% (95.3%) for SD-OCTA. Manual modification of segmentation increased sensitivity to 79.3% for SS-OCTA but not for SD-OCTA (58.6%). The combination of en face OCTA with cross-sectional OCTA reached highest sensitivity values (SS-OCTA: 82.8%, SD-OCTA: 86.2%), and lowest number of cases with discrepancies between SS-OCTA and SD-OCTA (4.2%). Fleiss kappa as measure of concordance between FA, SS-OCTA, and SD-OCTA was 0.56 for the automated slabs, 0.60 for the manual slabs, and 0.73 (good agreement) for the combination of en face OCTA with cross-sectional OCTA. Concordance to FA was moderate for the automated slabs and good for manual slabs and combination with cross-sectional OCTA of both devices. Conclusion Both devices reached comparable results regarding the detection of MNV on OCTA. Sensitivity for MNV detection and agreement between devices was best when evaluating a combination of en face and cross-sectional OCTA.

Optical Coherence Tomography Angiography for Anterior Segment Vasculature Imaging

Ophthalmology ◽  
2015 ◽  
Vol 122 (9) ◽  
pp. 1740-1747 ◽  
Author(s):  
Marcus Ang ◽  
Dawn A. Sim ◽  
Pearse A. Keane ◽  
Chelvin C.A. Sng ◽  
Catherine A. Egan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Optical Coherence

scholarly journals Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Riham S. H. M. Allam ◽  
Rania A. Ahmed
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Normal Subjects ◽  
Cross Sectional Study ◽  
Spectral Domain ◽  
Outer Diameter ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Air Bubble ◽  
Inner Diameter

Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT).Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured.Results. 24 males and 52 females (mean age44±14.35 y) were included. Lower punctum was perceived by OCT to be an area with an outer diameter (mean412.16±163 μm), inner diameter (mean233.67±138.73 μm), and depth (mean251.7±126.58 μm). The OCT measured outer punctum diameter was significantly less than that measured clinically (P: 0.000). Seven major shapes were identified. The junction with the vertical canaliculus was detectable in 44%. Fluid was detected in 34%, one of which had an air bubble; however, 63% of punctae showed no contents and 4% had debris.Conclusions. AS-OCT can be a useful tool in understanding the anatomy of the punctum and distal lacrimal system as well as tear drainage physiology. Measuring the punctum size may play a role in plugs fitting.

scholarly journals Investigation of Macular Choroidal Thickness and Blood Flow Change by Optical Coherence Tomography Angiography After Posterior Scleral Reinforcement

2021 ◽  
Vol 8 ◽  
Author(s):  
Zheng Zhang ◽  
Yue Qi ◽  
Wenbin Wei ◽  
Zi-Bing Jin ◽  
Wen Wang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
High Myopia ◽  
Choroidal Thickness ◽  
Optical Coherence Tomography Angiography ◽  
Pathologic Myopia ◽  
Optical Coherence ◽  
Short Period ◽  
Posterior Scleral Reinforcement

Purpose: This work aimed to study the effect of posterior scleral reinforcement (PSR) on choroidal thickness (CT) and blood flow.Methods: This study included 25 eyes of 24 patients with high myopia ( ≤ -6.0 dioptres or axial length ≥ 26.0 mm) who underwent PSR surgery. All patients completed the 1-month follow-up visit. Myopic macular degeneration (MMD) was graded according to the International Meta-Analysis for Pathologic Myopia (META-PM) classification based on color fundus photographs. Swept-source optical coherence tomography angiography (SSOCTA) was performed to investigate CT, choroidal perfusion area (CPA), and choriocapillaris perfusion area (CCPA) change following PSR surgery.Results: The distribution of MMD categories was 9 (36.0%) in category 1, 10 (40.0%) in category 2, and 6 (24.0%) in category 3 or 4. MMD severity was strongly correlated with CT (all P &lt; 0.01) and CPA (all P &lt; 0.04). Postoperative CT at each sector increased significantly at 1 week's follow-up, compared to preoperative measures (all P &lt; 0.05). Postoperative CPA at subfoveal, superior, inferior, and nasal sectors also increased significantly 1 week after PSR surgery (all P &lt; 0.05). Moreover, the increased CT, CPA, and CCPA remain after PSR surgery at 1 month's follow-up, but the difference was not statistically significant.Conclusions: We demonstrated that the CT and choroidal blood flow increased significantly in patients with high myopia who underwent PSR surgery in a short period of time. In addition, the CT and CPA were independently associated with MMD. However, whether the transient improvement of the choroidal circulation could prevent long-term progression of high myopia warrants further study in the future.

scholarly journals Assessment of choriocapillary blood flow changes in response to half-dose photodynamic therapy in chronic central serous chorioretinopathy using optical coherence tomography angiography

2020 ◽  
Author(s):  
Juejun Liu ◽  
Changzheng Chen ◽  
Lu Li ◽  
Yishuang Xu ◽  
Zuohuizi Yi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Photodynamic Therapy ◽  
Central Serous Chorioretinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Chronic Central Serous Chorioretinopathy ◽  
Half Dose ◽  
Flow Changes

Abstract Background: Optical coherence tomography angiography (OCTA) is a newly developed imaging quantitative technique for analysis of choriocapillaris (CC) flow changes, thereby exploring the pathological mechanism of chronic central serous chorioretinopathy (CCSC) and the therapeutic effects of photodynamic therapy (PDT). In this study, we sought to quantify the blood flow changes in CC of CCSC patients receiving half-dose PDT using OCTA.Methods: A total of 28 affected eyes and 24 unaffected eyes of 26 CCSC patients receiving half-dose PDT, and 40 eyes of 20 healthy gender- and age-matched subjects were retrospectively enrolled in this study. The proportion of total areas of flow signal voids (FSV, %) in CC level of OCTA was assessed in both eyes of the CCSC patients at baseline and repeated in multiple sections at 1-week, 1-month, 3-month and 6-month intervals after PDT. In addition, the CC patterns in response to PDT at early stage and the subsequent morphologic changes were qualitatively documented using OCTA.Results: For affected eyes, FSV at 6-m follow-up was significantly lower than that at 1-m follow-up (p=0.036). When compared to normal control eyes, FSV in affected eyes was significantly higher at 1-m, 3-m and 6-m follow-up (p<0.05 for all), and FSV in unaffected eyes was significantly higher at baseline, 1-w, 1-m and 3-m follow-up (p<0.05 for all). Three CC patterns of early response to PDT were identified, including signs of recovery with more even flow signals, transient appearance of worse ischemia and secondary neovascularization within CC level.Conclusion: Abnormal CC flow attenuation remains in completely resolved eyes of CCSC patients treated with half-dose PDT.

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