共0篇 平均IF=NaN (-)更多分析

    加载中

    logo
    Topographic Variations of Choroidal Thickness in Healthy Eyes on Swept-Source Optical Coherence Tomography. Touhami Sara,Philippakis Elise,Mrejen Sarah,Couturier Aude,Casteran Céline,Levent Priscille,Tadayoni Ramin,Gaudric Alain Investigative ophthalmology & visual science Purpose:To assess topographic variations of choroidal thickness (CT) in the fovea and beyond in healthy eyes. Methods:This cross-sectional study included healthy subjects ≤ 55 years of age with axial lengths (22-26 mm) and refractive error margins (-4D, +4D) in normal ranges. Images were acquired using swept-source optical coherence tomography angiography (OCT-A). Corneal thickness (CT) maps from 12 × 12-mm radial scans and 9 × 9-mm OCT-A B-scans were analyzed. Results:The study included 64 eyes of 33 subjects (mean age, 37 years). Mean CT was >300 µm in all locations except the nasal outer macula. The subfoveal CT was >395 µm in 30% of cases; in 38.7% of cases, >50% of the CT map was thicker than 395 µm. The mean thickest choroidal point was 395.2 µm (range, 164-548 µm), located superior and temporal to the macula in 72.2% of cases and subfoveally in 1.8% of cases. The CT pattern was symmetrical (58%) or asymmetrical (42%) along a horizontal axis correlating with choroidal vein distribution. Half of the asymmetrical patterns were thicker in the inferior quadrants, with an oblique temporal watershed of venous drainage, and the other half were thicker superiorly. The mean vascularity index was ∼75% regardless of the mean CT. Conclusions:One-third of healthy eyes of patients younger than age 55 had a thick choroid (>395 µm). In these normal eyes, the thickest choroidal point was not subfoveal, CT symmetry above and below the fovea depended on choroidal vein distribution, and choroidal vascularity index was independent from CT. No patients demonstrated fundus autofluorescence abnormalities, and the choriocapillaris remained visible even in thick choroids. These features could be interesting when differentiating normal versus pathological states. 10.1167/iovs.61.3.38
    Optical Coherence Tomography Angiography Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes. Yarmohammadi Adeleh,Zangwill Linda M,Diniz-Filho Alberto,Suh Min Hee,Manalastas Patricia Isabel,Fatehee Naeem,Yousefi Siamak,Belghith Akram,Saunders Luke J,Medeiros Felipe A,Huang David,Weinreb Robert N Investigative ophthalmology & visual science PURPOSE:The purpose of this study was to compare retinal nerve fiber layer (RNFL) thickness and optical coherence tomography angiography (OCT-A) retinal vasculature measurements in healthy, glaucoma suspect, and glaucoma patients. METHODS:Two hundred sixty-one eyes of 164 healthy, glaucoma suspect, and open-angle glaucoma (OAG) participants from the Diagnostic Innovations in Glaucoma Study with good quality OCT-A images were included. Retinal vasculature information was summarized as a vessel density map and as vessel density (%), which is the proportion of flowing vessel area over the total area evaluated. Two vessel density measurements extracted from the RNFL were analyzed: (1) circumpapillary vessel density (cpVD) measured in a 750-μm-wide elliptical annulus around the disc and (2) whole image vessel density (wiVD) measured over the entire image. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy. RESULTS:Age-adjusted mean vessel density was significantly lower in OAG eyes compared with glaucoma suspects and healthy eyes. (cpVD: 55.1 ± 7%, 60.3 ± 5%, and 64.2 ± 3%, respectively; P < 0.001; and wiVD: 46.2 ± 6%, 51.3 ± 5%, and 56.6 ± 3%, respectively; P < 0.001). For differentiating between glaucoma and healthy eyes, the age-adjusted AUROC was highest for wiVD (0.94), followed by RNFL thickness (0.92) and cpVD (0.83). The AUROCs for differentiating between healthy and glaucoma suspect eyes were highest for wiVD (0.70), followed by cpVD (0.65) and RNFL thickness (0.65). CONCLUSIONS:Optical coherence tomography angiography vessel density had similar diagnostic accuracy to RNFL thickness measurements for differentiating between healthy and glaucoma eyes. These results suggest that OCT-A measurements reflect damage to tissues relevant to the pathophysiology of OAG. 10.1167/iovs.15-18944
    OCT Angiography: Measurement of Retinal Macular Microvasculature with Spectralis II OCT Angiography - Reliability and Reproducibility. Hosari Sami,Hohberger Bettina,Theelke Luisa,Sari Hasan,Lucio Marianna,Mardin Christian Y Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde AIM:The aim of the present study was to investigate the reliability of macular microvasculature measurements in normal subjects by Heidelberg Spectralis II optical coherence tomography angiography (OCT-A) in combination with a newly made software. SUBJECTS AND METHODS:This prospective study included 23 eyes of 23 persons from the Erlangen Glaucoma Registry (ISSN 2191-5008, CS-2011; NTC00494923). The subjects underwent a complete clinical, standardized ophthalmologic examination to rule out any eye disease. En face OCT-A imaging was done using Heidelberg Spectralis II OCT (Heidelberg, Germany). Images were recorded with a 15 × 15° angle and a lateral resolution of 5.7 µm/pixel, resulting in a retinal section of 2.9 × 2.9 mm. The Erlangen-Angio-Tool (EA-Tool) OCT-A application performed multiple segmentations, allowing analysis of the vessel density in 12 segments. The software was coded in MATLAB. Macular data on the superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were exported into the application and analyzed separately. The EA-Tool calculated the percentage of "white area" in the "total area" of the region of interest, called vessel density. Foveolar avascular zones (FAZs) of the SVP, ICP, and DCP were calculated manually. To investigate the reproducibility of the new software, individual scans (SVP, ICP, and DCP) were analyzed twice with the EA-Tool and intraclass coefficients (ICCs) of the vessel density values were calculated. Statistical analysis was performed with SPSS version 21.0. RESULTS:The mean vessel density of the SVP ranged between 30.4 and 33.5, that of the ICP between 20.9 and 24.7, and that of the DCP between 23.5 and 27.6. Bland-Altman plots showed a good reliability of two consecutive scans of each sector (S1-S12) in the SVP, ICP, and DCP. Testing reproducibility, no statistically significantly different sectorial coefficients of variation of the SVP, ICP, and DCP were observed (p > 0.05). The mean FAZ area of the SVP was 0.43 ± 0.16 mm2, that of the ICP 0.28 ± 0.1 mm2, and that of the DCP 0.44 ± 0.12 mm2. CONCLUSIONS:Spectralis OCT II, in combination with the semiautomated vessel density software EA-Tool, showed good or even excellent ICCs in 75% of all segments of the SVP, ICP, and DCP. The ICCs for the FAZ area in the SVP, ICP, and DCP were excellent. 10.1159/000502458
    Changes in Retinal Optical Coherence Tomography Angiography Indexes Over 24 Hours. Investigative ophthalmology & visual science Purpose:To evaluate changes in the retinal microvasculature of young adults over 24 hours using optical coherence tomography angiography (OCT-A). Methods:Participants (n = 44, mean age 23.2 ± 4.1 years, 24 myopes and 20 nonmyopes) with normal ophthalmological findings were recruited. Two macular OCT-A and OCT scans, systemic blood pressure, intraocular pressure (IOP), and biometry measurements were taken every four hours over 24 hours. Superficial and deep retinal layer en face images were analyzed to extract magnification-corrected vascular indexes using image analysis including foveal avascular zone metrics, vessel density, and perfusion density for the foveal, parafoveal, and perifoveal zones. Results:Significant diurnal variations (P < 0.001) were observed in the vessel and perfusion density in the three superficial retinal layer regions, with acrophase between 4:30 PM and 8:30 PM. Only foveal and parafoveal regions of the deep retinal layer exhibited significant diurnal variations with acrophase between 9 AM and 3 PM. Myopes and nonmyopes had different acrophases but not amplitudes in the parafoveal perfusion density of superficial retinal layer (P = 0.039). Significant correlations were observed between diurnal amplitudes or acrophases of superficial retinal layer indexes and systemic pulse pressure, IOP, axial length and retinal thickness. Conclusions:This study shows, for the first time, that significant diurnal variation exists in OCT-A indexes of macular superficial and deep retinal layer over 24 hours and were related to variations in various ocular and systemic measurements. Myopes and nonmyopes showed differences in the timing but not in amplitude of the superficial retinal layer parafoveal perfusion density variations but not in deep retinal layer. 10.1167/iovs.63.3.25
    Quantitative Optical Coherence Tomography Angiography of Radial Peripapillary Capillaries in Glaucoma, Glaucoma Suspect, and Normal Eyes. Mammo Zaid,Heisler Morgan,Balaratnasingam Chandrakumar,Lee Sieun,Yu Dao-Yi,Mackenzie Paul,Schendel Steven,Merkur Andrew,Kirker Andrew,Albiani David,Navajas Eduardo,Beg Mirza Faisal,Morgan William,Sarunic Marinko V American journal of ophthalmology PURPOSE:To evaluate the quantitative characteristics of the radial peripapillary capillary (RPC) network in glaucoma, glaucoma suspect, and normal eyes using speckle variance optical coherence tomography angiography (OCT-A). To determine correlations between RPC density, nerve fiber layer (NFL) thickness, and visual field indices. DESIGN:Cross-sectional study. METHODS:OCT-A images of RPCs were acquired at a single institution using a custom-built 1060 nm system from 3 groups: unilateral glaucoma (10 eyes from 5 subjects), glaucoma suspects (6 eyes from 3 subjects), and normal control eyes (16 eyes from 9 normal subjects). Peripapillary NFL thickness measurements were determined using spectral-domain optical coherence tomography. Glaucoma and glaucoma suspects also underwent automated 30-2 Humphrey visual field analysis. Manual tracing techniques were used to quantify RPC density in the OCT-A images. Data were analyzed using a linear mixed model with 1 fixed-effect covariate. Correlations between main outcome measures (RPC density, NFL thickness, and visual field index) were determined. RESULTS:Mean age was not significantly different between the 3 groups (P = .25). The density of RPCs was significantly lower in glaucomatous eyes compared with matched-peripapillary regions in the fellow eye, glaucoma suspect group, and normal group (all P < .001). RPC density was strongly correlated with NFL thickness (P < .001) and visual field index (P < .001). CONCLUSIONS:Significant reductions in RPC density were correlated with sites of NFL decrease and visual field loss in glaucoma. Speckle variance OCT-A allows visualization and quantification of RPCs and may therefore be a useful tool for indirectly quantifying and monitoring retinal ganglion cell axonal injury in glaucoma. 10.1016/j.ajo.2016.07.015
    Comparison of vascular parameters between normal cynomolgus macaques and healthy humans by optical coherence tomography angiography. Peng Jingyi,Zhong Liuxueying,Ma Li,Jin Jiayi,Zheng Yongxin,Jin Chenjin BMC ophthalmology BACKGROUND:The metabolic activity of retina is higher than other human tissues and is crucial to the vision. Cynomolgus macaques is widely used in ophthalmic disease research. The evaluation and comparison of macular and optic disc vascular circulation parameters between normal adult cynomolgus macaques and healthy adult humans using OCT-A can promote better use of nonhuman primate models in studies of ophthalmic vascular disease. METHODS:Twelve normal adult cynomolgus macaques with a mean age of 4.91 ± 0.43 years were studied for data collection. The macula of 28 adult healthy humans (14 males and 14 females), with a mean age of 25.11 ± 6.21 years and the optic discs of 9 adult healthy humans (4 males and 5 females) with a mean age of 28.56 ± 6.78 years were measured. The vessel density (VD) was measured using an RTVue XR with AngioVue. The scan sizes of the macular and optic discs were 3 × 3 mm and 4.5 × 4.5 mm, respectively. RESULTS:OCT-A can image the superficial and deep capillary plexuses and radial peripapillary capillary network. In RPC layer of the optic disc, the VD in the nasal quadrant was lower than the VD in the inferior temporal quadrant. Similarities and significant differences in VD between healthy humans and cynomolgus macaques were obtained using OCT-A. CONCLUSIONS:This study provides normal vascular parameters for adult cynomolgus macaques using OCT-A to help establish an optical parameter database for cynomolgus macaques and compare VD between healthy humans and cynomolgus macaques to promote choroid-retinopathy research. TRIAL REGISTRATION:Current Controlled Trials NCT03692169 , retrospectively registered on 26 sept 2018. 10.1186/s12886-019-1207-x
    Interocular symmetry of the foveal avascular zone area in healthy eyes: a swept-source optical coherence tomography angiography study. Liu Mengxuan,Fujiwara Atsushi,Morizane Yuki,Kawasaki Ryo,Kimura Shuhei,Morizane-Hosokawa Mio,Shiode Yusuke,Hirano Masayuki,Doi Shinichiro,Toshima Shinji,Takahashi Kosuke,Hosogi Mika,Ma Xiang,Shiraga Fumio Japanese journal of ophthalmology PURPOSE:To determine the presence or absence of interocular differences in the foveal avascular zone (FAZ) area in healthy eyes. STUDY DESIGN:Cross-sectional study. METHODS:We examined 236 healthy eyes of 118 consecutive subjects (mean age, 39.1 ± 18.9 years). We used swept-source optical coherence tomography angiography (OCTA) images of the FAZ to measure its area from both the superficial capillary plexus (SCP-FAZ) and the whole retinal capillary plexus (WCP-FAZ). We also investigated the relationship between interocular differences in SCP-FAZ and other factors such as: axial length, spherical equivalent, central retinal thickness, and retinal vascular density. RESULTS:There was no significant difference in the FAZ area between the right and left eyes in either the SCP-FAZ (P = 0.61) or WCP-FAZ (P = 0.80), and the FAZ areas of both eyes showed significant positive correlations (SCP-FAZ; P < 0.001, R = 0.884, WCP-FAZ; P < 0.001, R = 0.856). Bland-Altman plots showed that the mean interocular difference in SCP-FAZ area was 0.002 ± 0.037 mm (95% confidence interval, -0.072-0.075 mm), and in the WCP-FAZ area, 0.050 ± 0.044 mm (95% confidence interval, -0.036-0.137 mm). Multivariate regression analysis showed that none of the investigated factors were significantly associated with interocular differences in SCP-FAZ (P = 0.61, R = 0.138). CONCLUSIONS:There was no significant interocular difference in SCP- and WCP-FAZ areas in healthy eyes. The normal range of values for interocular difference in SCP-FAZ area was 0.002 ± 0.037 mm and in the WCP-FAZ area, 0.050 ± 0.044 mm. 10.1007/s10384-020-00719-2
    Assessment of relationship between retinal perfusion and retina thickness in healthy children and adolescents. PloS one PURPOSE:To determine the correlations between inner, mid, and outer retinal thickness (RT) and allied retinal and choroidal vascular densities (VD) at macula in normal healthy children and adolescents. METHODS:This cross-sectional study included a total of 108 eyes of 59 subjects. Optical coherence tomography angiography (OCTA-Optovue) was used to measure the thickness of the inner-retina (IRT), mid-retina (MRT), and outer-retina (ORT) at foveal (central 1mm), parafoveal (1-3 mm), and perifoveal (3-6 mm) areas, as well as the corresponding VD of the superficial capillary plexus (SVD), deep capillary plexus (DVD), and choricapillaris (CVD). RESULTS:The study enrolled 108 normal eyes from 54 participants with a mean age of 10.9 years. Partial correlations showed that the nasal and inferior parafoveal and perifoveal subsegments IRT, MRT and ORT are more affected by all SVD, DVD, and CVD. Nasal parafoveal and perifoveal MRT and all three capillary layers have a constant negative correlation. ORT was not affected by all three layers except for CVD at fovea. The regression analysis revealed that SVD and CVD were significantly associated with foveal and parafoveal and perifoveal IRT. DVD and gender could significantly affect perifoveal IRT. However, only CVD was significantly affected foveal MRT. Based on regression analysis, only CVD was significantly associated with foveal and parafoveal ORT, but not with perifoveal ORT. CONCLUSION:The thickness of different retinal layers correlates with retinal and choroidal VD in different ways according to their zones. 10.1371/journal.pone.0273001
    [Evaluation of choriocapillaris with high-speed spectral-domain optical coherence tomography angiography and image averaging]. Maltsev D S,Fomin A V,Kulikov A N,Vasiliev A S Vestnik oftalmologii PURPOSE:To study the capabilities of high-speed spectral-domain optical coherence tomography angiography (SD-OCTA) with image averaging in the evaluation of choriocapillaries in healthy individuals and patients with central serous chorioretinopathy (CSC). MATERIAL AND METHODS:All participants underwent OCTA examination on the SOLIX tomograph (Optovue, USA) using quadruplicate 3×3 mm scan with image averaging. Image analysis was performed in 9-µm custom slab with Phansalkar auto local threshold algorithm and calculation of flow voids larger than 5000 µm and 10 000 µm. The optimal slab depth was determined in healthy eyes by consecutive analysis of the slabs with a 3-µm shift from zero position to 33 µm below Bruch's membrane. RESULTS:The study included 18 eyes of 18 healthy volunteers (40.4±6.0 years old) and 18 fellow eyes of 18 unilateral CSC patients (37.4±10.7 years old). The slab 12 µm below the Bruch's membrane showed the minimal number of flow voids (23.1±7.0 of >5000 µm voids per scan) and was chosen for further analysis. The number of flow voids of >5000 µm in healthy paired eyes of CSC patients was statistically significantly higher than in the eyes of healthy individuals (32.7±10.7 and 25.3±8.1 voids/scan, respectively; =0.022). The number of flow voids of >10000 µm was also statistically significantly higher in CSC eyes compared to healthy eyes (5.6±3.3 and 3.5±1.9 voids/scan, respectively; =0.045). There was no statistically significant difference in total area of the voids between the eyes of healthy individuals and CSC patients (96406.1±3924.5 µm and 95395.7 ± 3615.1 µm, respectively; =0.42). CONCLUSION:The optimal settings for choriocapillaris imaging on the SOLIX tomograph include 9-µm slab 9 to 18 µm below the Bruch's membrane. Using a 9-µm slab 12 µm below the Bruch's membrane, a substantial difference was found in choriocapillaris perfusion between eyes of healthy individuals and CSC patients. 10.17116/oftalma202113703176
    Effects of physical exercise on macular vessel density and choroidal thickness in children. Li Shufeng,Pan Yiguo,Xu Jingjing,Li Xue,Spiegel Daniel P,Bao Jinhua,Chen Hao Scientific reports We used swept-source (SS) optical coherence tomography (OCT) and OCT angiography (OCTA) to investigate the effects of moderate physical exercise on retinal and choroidal vessel densities (VDs) and thicknesses in children. One eye in each of 40 myopic children (mean age, 11.70 years) and 18 emmetropic children (mean age, 11.06 years) were included. SS-OCT 6 × 6-mm radial scans and SS-OCTA 3 × 3-mm images were centered on the macula. Heart rate (HR), systolic and diastolic blood pressure, and intraocular pressure (IOP) were recorded before and immediately after a 20-min stationary cycling exercise and after a 30-min rest. The subfoveal choroidal thickness (SFCT), choroidal thickness (CT), and VD at the superficial and deep retinal layers, choriocapillaris, and deeper choroidal vessels were determined. SFCT and CT were significantly lower at all locations immediately after exercise (p < 0.001) and did not fully recover after rest (p < 0.05). VD was lower in the deep retinal layer after exercise (p = 0.02) and higher in the superficial layer after rest (p = 0.03) in myopic eyes while it was higher in the superficial (p < 0.01) and deep layer (p < 0.01) after rest in emmetropic eyes. No significant exercise-related changes in the superficial retinal VD, choroidal VD, or IOP were observed. ΔCT% and ΔSFCT% were significantly correlated with increases in HR in myopic group (p = 0.04 and p = 0.03, respectively). Exercise increased retinal VD after rest in emmetropic eyes, and caused significant CT thinning that lasted for at least 30 min in both emmetropic and myopic eyes. 10.1038/s41598-021-81770-y
    Assessment of Macular Microvasculature in Healthy Eyes of Infants and Children Using OCT Angiography. Hsu S Tammy,Ngo Hoan T,Stinnett Sandra S,Cheung Nathan L,House Robert J,Kelly Michael P,Chen Xi,Enyedi Laura B,Prakalapakorn S Grace,Materin Miguel A,El-Dairi Mays A,Jaffe Glenn J,Freedman Sharon F,Toth Cynthia A,Vajzovic Lejla Ophthalmology PURPOSE:To assess macular vasculature in healthy infants and children using OCT angiography (OCTA). DESIGN:Prospective cross-sectional study. PARTICIPANTS:One hundred thirty-five normal maculae of 89 healthy infants and children (mean age, 8.5±5.3 years; range, 9 weeks-17 years) treated at the Duke University Eye Center. METHODS:We imaged 135 maculae of 89 pediatric patients using the standard Spectralis tabletop and investigational Spectralis with Flex module devices, both equipped with investigational OCTA software (Heidelberg Engineering, Heidelberg, Germany). OCT angiography images of the superficial vascular complex (SVC) and deep vascular complex (DVC) were analyzed for foveal avascular zone (FAZ) area and superficial and deep vessel density. We assessed effects of age, gender, race, axial length (AL), and central subfield thickness on FAZ and vessel density. Patients with both eyes imaged were assessed for agreement between the FAZ and vessel densities of the left and right eyes. MAIN OUTCOME MEASURES:The FAZ area, as well as vessel area density (VAD) and vessel length density (VLD) in the SVC and DVC. RESULTS:The FAZ varied significantly with race; white patients showed a significantly smaller FAZ than black patients (mean difference, 0.11 mm; P = 0.004). The FAZ did not vary with age, gender, or AL (P > 0.05). In the SVC, VAD and VLD varied significantly with age (P < 0.001) and AL (R = 0.46; P < 0.001) but not gender (P > 0.05). The SVC VLD was significantly different between races and ethnicities (P = 0.037), but VAD was not (P < 0.05). In the DVC, VAD and VLD also varied significantly with age (P < 0.001) and AL (R = 0.46; P < 0.001) but not gender or race (P > 0.05). There was excellent agreement between the right and left eyes for FAZ (intraclass correlation [ICC], 0.97), SVC VLD (ICC, 1.00), and DVC VLD (ICC, 1.00). CONCLUSIONS:Quantitative studies of pediatric perifoveal vasculature should consider age, race, and AL. In eyes with unilateral disease, the perifoveal vasculature in the unaffected eye may be used as a control comparison because there is excellent agreement between eyes. 10.1016/j.ophtha.2019.06.028
    An Optical Coherence Tomography Angiography Study of the Relationship Between Foveal Avascular Zone Size and Retinal Vessel Density. Kwon Junki,Choi Jaewan,Shin Joong Won,Lee Jiyun,Kook Michael S Investigative ophthalmology & visual science Purpose:To assess the relationship between the size of the foveal avascular zone (FAZ; area and perimeter) and vessel density (VD) at various retinal regions using optical coherence tomography angiography (OCTA) in patients with open-angle glaucoma (OAG). Methods:In this retrospective cross-sectional study, OAG eyes were grouped according to the presence/absence of central visual field (CVF) defects. A control group of normal eyes was also included. OCTA images were obtained from the optic nerve (4.5 × 4.5 mm2) and macular (3 × 3 mm2) area, in which VDs were measured in the circumpapilla, parafovea, and fovea regions. Partial correlation analyses between FAZ parameters representing size and VDs at different retinal regions were performed. The correlation between FAZ parameters and macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and CVF mean sensitivity (MS) was also assessed. For spatial correspondence, correlations between FAZ parameters and corresponding VD, mGCIPLT, and CVF-MS measurements were assessed at each hemiretina. Results:A total of 126 OAG eyes and 40 controls were reviewed. Overall, FAZ parameters showed statistically significant correlations with VDs measured at the fovea, parafovea, and circumpapilla (FAZ area: r = -0.603, -0.385, -0.256; P < 0.001, < 0.001, and 0.003, respectively). These correlations were observed regardless of the presence of CVF defects (all P < 0.05). FAZ size showed significant spatial correlations with VD, mGCIPLT, and CVF-MS measurements at each hemiretina. Conclusions:OCTA-derived FAZ area and perimeter showed statistically significant correlations with VDs measured at various retinal locations with spatial correspondence in OAG. 10.1167/iovs.18-24168
    Unmeasurable small size of foveal avascular zone without visual impairment in optical coherence tomography angiography. Yokoyama Tatsuro,Maruko Ichiro,Koizumi Hideki,Ishikawa Yutaka,Iida Tomohiro Eye (London, England) PURPOSE:To report the clinical characteristics of eyes with an unmeasurable small size of foveal avascular zone (FAZ) in the optical coherence tomography angiographic (OCTA) images. METHODS:Two-hundred sixty-seven eyes of 255 patients (mean age 60.4 years) without retinal and choroidal disorders to cause any type of visual impairment were examined by optical coherence tomography angiography (OCTA; RTVue XR Avanti, Optovue, Fremont, CA). Cross-sectional images at the fovea (DRI-OCT, Topcon, Japan) and fundus autofluorescence (CX-1 MYD/NM, Canon, Japan) were also recorded from all eyes. RESULTS:Four eyes (1.5%) of 3 patients (2 men, 1 woman; average age, 63.3 years) were found to have an unmeasurable small size of FAZ in the OCTA images. The best-corrected visual acuity was better than 20/20 in all eyes. Cross-sectional OCT images showed the presence of a foveal depression and the inner retinal layers in the foveal depression. These inner retinal layers were detected as a hyperreflective bands at the fovea. Fundus autofluorescence showed hypo-autofluorescence at the fovea as in normal eyes. CONCLUSIONS:An unmeasurable small size of FAZ without visual impairment was detected in 1.5% of 267 normal eyes. These eyes may be classified as low-grade foveal hypoplasia. 10.1038/s41433-017-0005-z
    Repeatability of ocular surface vessel density measurements with optical coherence tomography angiography. Cai Sijie,Zhao Fengping,Du Chixin BMC ophthalmology BACKGROUND:To determine the repeatability of measurements of ocular surface vessel density in normal and diseased eyes using optical coherence tomography angiography (OCTA). METHODS:Ten normal eyes, 10 pinguecula eyes, and 10 pterygium eyes of 30 volunteers were subjected to OCTA (AngioVue Imaging System, Optovue, Inc.). For scanning, we used the corneal adapter module. Each eye was scanned three times in the nasal and temporal directions, separately. AngioVue software was used to generate the ocular surface vessel density. Ocular surface vessel density was defined as the proportion of vessel area with blood flow to the total measurement area (3 × 3 mm). Intersession repeatability of the measurement was summarized as the coefficient of variation (CV), and intraclass correlation coefficients (ICC) were calculated by variance component models. RESULTS:The CVs were less than 5% in all subjects, and the ICCs exceeded 0.9; thus, all measurements showed good repeatability. The nasal vessels densities differed significantly between healthy eyes and eyes with pterygium (P < 0.05); however, there was no significant difference between healthy eyes and eyes with pinguecula (P = 0.466). CONCLUSIONS:These results suggest that measurement of ocular surface vessel density by OCTA in normal eyes and eyes with pterygium and pinguecula is repeatable. This preliminary research describes a quantitative and visual method for assessing vessel density of the ocular surface with a high level of consistency. 10.1186/s12886-019-1255-2
    Evaluation of Automatically Quantified Foveal Avascular Zone Metrics for Diagnosis of Diabetic Retinopathy Using Optical Coherence Tomography Angiography. Lu Yansha,Simonett Joseph M,Wang Jie,Zhang Miao,Hwang Thomas,Hagag Ahmed M,Huang David,Li Dengwang,Jia Yali Investigative ophthalmology & visual science Purpose:To describe an automated algorithm to quantify the foveal avascular zone (FAZ), using optical coherence tomography angiography (OCTA), and to compare its performance for diagnosis of diabetic retinopathy (DR) and association with best-corrected visual acuity (BCVA) to that of extrafoveal avascular area (EAA). Methods:We obtained 3 × 3-mm macular OCTA scans in diabetic patients with various levels of DR and healthy controls. An algorithm based on a generalized gradient vector flow (GGVF) snake model detected the FAZ, and metrics assessing FAZ size and irregularity were calculated. We compared the automated FAZ segmentation to manual delineation and tested the within-visit repeatability of FAZ metrics. The correlations of two conventional FAZ metrics, two novel FAZ metrics, and EAA with DR severity and BCVA, as determined by Early Treatment Diabetic Retinopathy Study (ETDRS) charts, were assessed. Results:Sixty-six eyes from 66 diabetic patients and 19 control eyes from 19 healthy participants were included. The agreement between manual and automated FAZ delineation had a Jaccard index > 0.82, and the repeatability of automated FAZ detection was excellent in eyes at all levels of DR severity. FAZ metrics that incorporated both FAZ size and shape irregularity had the strongest correlation with clinical DR grade and BCVA. Of all the tested OCTA metrics, EAA had the greatest sensitivity in differentiating diabetic eyes without clinical evidence of retinopathy, mild to moderate nonproliferative DR (NPDR), and severe NPDR to proliferative DR from healthy controls. Conclusions:The GGVF snake algorithm tested in this study can accurately and reliably detect the FAZ, using OCTA data at all DR severity grades, and may be used to obtain clinically useful information from OCTA data regarding macular ischemia in patients with diabetes. While FAZ metrics can provide clinically useful information regarding macular ischemia, and possibly visual acuity potential, EAA measurements may be a better biomarker for DR. 10.1167/iovs.17-23498
    Long-term repeatability of optical coherence tomography angiography parameters in healthy eyes. Lee Min-Woo,Nam Ki-Yup,Lim Hyung-Bin,Koo Hyung-Moon,Shin Yong-Il,Kim Jung-Yeul Acta ophthalmologica PURPOSE:To determine the long-term repeatability of optical coherence tomography angiography (OCTA) parameters in normal eyes. METHODS:We prospectively enrolled 104 normal eyes. Participants were divided into three groups based on differences in the signal strength (SS) of OCTA scans obtained at two visits at least 6 months apart: group 1, SS difference = 2; group 2, 1; group 3, 0. We measured a foveal centred scan area of 3 × 3 mm pattern. All measurements were performed twice at 5-min intervals at the initial visit. The second measurements were performed at least 6 months later. RESULTS:In short-term vessel density (VD) repeatability, the coefficient of variation (CV) ranged from 3.89% to 8.10% and the intraclass correlation coefficient (ICC) ranged from 0.785 to 0.941. In terms of long-term repeatability, the CV was 5.39-12.62% and the ICC was 0.598-0.867. In group 1, the ICCs of the inner and full VDs were 0.194 and 0.221, respectively. In groups 2 and 3, the ICCs of the inner and full VDs were 0.611 and 0.603, and 0.763 and 0.765, respectively. The central VDs of all groups had high CV besides high ICC. CONCLUSIONS:Optical coherence tomography angiography parameters showed good short-term and reasonable long-term repeatability in normal individuals. The differences in SSs between measurements affected such repeatability, so physicians should query the reliability of OCTA parameters when the differences in SS are 2 or more even when the SS is high. 10.1111/aos.14203
    Retinal Capillary Density and Foveal Avascular Zone Area Are Age-Dependent: Quantitative Analysis Using Optical Coherence Tomography Angiography. Iafe Nicholas A,Phasukkijwatana Nopasak,Chen Xuejing,Sarraf David Investigative ophthalmology & visual science PURPOSE:The purpose of this study was to quantify retinal capillary density and the foveal avascular zone (FAZ) area in normal subjects according to age, using optical coherence tomography angiography (OCTA). METHODS:All eyes in this cross-sectional study underwent OCTA using RTVue XR Avanti with AngioVue. OCTA scans were analyzed and processed, and vessel density and FAZ dimensions were calculated. RESULTS:A total of 113 normal eyes from 70 subjects were included (30 males, 40 females; mean 48 ± 20 years of age). The mean vessel density and FAZ dimensions were significantly smaller in the superficial retinal capillary plexus (SCP) than in the deep retinal capillary plexus (DCP), using quantitative OCTA analysis (all P< 0.0001). With 3 × 3-mm scans, the mean vessel density was 13.431 ± 1.758 mm-1 in the SCP, 18.812 ± 1.796 mm-1 in the DCP, and 5.913 ± 1.308 mm-1 and 10.447 ± 1.262 mm-1 with 6 × 6-mm scans in the SCP and DCP, respectively. Mean FAZ areas were 0.289 ± 0.108 mm2 at the SCP and 0.614 ± 0.200 mm2 at the DCP. Age was a predictor of SCP and DCP vessel density and FAZ area in the SCP. Vessel density decreased 0.0393 mm-1 (0.26%) per year in the SCP and 0.0574 mm-1 (0.27%) per year in the DCP. FAZ areas increased 0.0014 mm2 (0.63%) and 0.0011 mm2 (0.20%) per year in the SCP and DCP, respectively. CONCLUSIONS:SCP and DCP vessel density decreased with increasing age, while FAZ area increased with age. Normal age-matched measurements provide important standardized values that may facilitate management of retinal vascular disorders. 10.1167/iovs.16-20045
    The repeatability of superficial retinal vessel density measurements in eyes with long axial length using optical coherence tomography angiography. Li Mengyang,Jin Enzhong,Dong Chongya,Zhang Chuan,Zhao Mingwei,Qu Jinfeng BMC ophthalmology BACKGROUND:To investigate the repeatability of superficial retinal vessel density measurements in healthy eyes with long axial length (AL) using optical coherence tomography angiography (OCTA). METHODS:There were 60 eyes of 31 volunteers enrolled in this cross-sectional observational study. All subjects underwent OCTA, AL and refraction test. The enrolled eyes were divided into the long AL group (26 mm ≤ AL < 28 mm) and normal AL group (22 mm ≤ AL < 26 mm). The vessel length density (VLD), perfusion density (PD), and fovea avascular zone (FAZ) of the superficial retinal vessel were evaluated. Repeatability was assessed by intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Pearson's r correlation was used to analyze the relation of AL and the absolute difference between two measurements. RESULTS:The 3 × 3 mm scan pattern showed good repeatability with all ICCs over 0.7. For all parameters of all scan patterns, the ICCs of the normal AL group were distinctly higher than those of the long AL group; this finding was also confirmed by Bland-Altman analysis. The correlation analysis of AL and repeatability of OCTA parameters showed significant negative correlations between the ALs and repeatability of VLD in 6 × 6 mm inner ring (r = 0.13, p = 0.01), VLD in 6 × 6 mm outer ring (r = 0.09, p = 0.02) and PD in 6 × 6 mm outer ring (r = 0.08, p = 0.03). CONCLUSIONS:The AL and the scanned area will both affect the repeatability of superficial retinal vessel density measurements in OCTA. 10.1186/s12886-018-0992-y
    Optimizing the Repeatability of Choriocapillaris Flow Deficit Measurement From Optical Coherence Tomography Angiography. Byon Iksoo,Alagorie Ahmed Roshdy,Ji Yongsok,Su Li,Sadda Srinivas R American journal of ophthalmology PURPOSE:To evaluate the impact of processing technique and slab selection on the repeatability of choriocapillaris (CC) flow deficit (FD) measurements as assessed using optical coherence tomography angiography (OCTA) DESIGN: Prospective, cross-sectional study. METHODS:Healthy subjects were imaged with 4 consecutive 3 × 3-mm OCTA using a swept-source OCT (PLEX elite 9000; Carl Zeiss Meditec). OCTA images were generated using the Max projection, and three 10-μm-thick slabs starting 11, 21, and 31 μm posterior to the automatically segmented retinal pigment epithelial band. The resultant images were binarized using the Phansalkar method with a 43.94-μm radius and then the CCFD% was computed. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were computed for the 4 acquisitions to assess the repeatability of the CCFD%. This entire analysis was repeated after separately modulating several parameters: (1) Sum instead of the Max projection, (2) retinal pigment epithelial fit instead of the retinal pigment epithelial band as the offset reference, (3) 14.65 and 87.88 μm radius values instead of 43.94 μm. RESULTS:Twenty-four healthy eyes (mean age; 36.4 years) were enrolled. The CCFD% in the 11-21-, 21-31-, and 31-41-μm slabs generated by the Max algorithm and the retinal pigment epithelial band showed high repeatability values (ICCs = 0.963, 0.975, and 911; CVs = 0.05, 0.05, and 0.05, respectively). As most of the cases were confounded with the hypointense region when the 11-21-μm slab was used, however, this slab could not be included in the subsequent analyses. Those values in the 21-31- and 31-41-μm slabs were higher than those of the corresponding slabs by the Sum algorithm (ICC = 0.916 and 0.776; CV = 0.15 and 0.19, respectively) or by the retinal pigment epithelial fit (ICC = 0.907 and 0.802; CV = 0.06 and 0.06, respectively). The Phansalkar radius of 43.94 μm had the highest ICC numerically, but this was not statistically significantly greater than for a radius of 14.65 μm (ICC = 0.960 and 0.911, respectively) or a radius of 87.88 μm (ICC = 0.958 and 0.897, respectively). Regardless of which parameter was modulated, the 21-31-μm slab was the most repeatable. CONCLUSIONS:In normal eyes, en face CC OCTA images generated using the Max projection and a 10-μm-thick slab offset of 21 μm below the instrument-generated retinal pigment epithelial band yielded the most repeatable CCFD%. These findings have implications for the design of standardized processing algorithms for quantitative CC assessment. 10.1016/j.ajo.2020.05.027
    Objective evaluation of size and shape of superficial foveal avascular zone in normal subjects by optical coherence tomography angiography. Shiihara Hideki,Terasaki Hiroto,Sonoda Shozo,Kakiuchi Naoko,Shinohara Yuki,Tomita Masatoshi,Sakamoto Taiji Scientific reports This study was conducted to investigate the size and shape of the foveal avascular zone (FAZ) determined by optical coherence tomography angiography (OCTA) and the relationship of the size and shape to the clinical findings in normal subjects. This was a cross-sectional study with seventy eyes of 70 volunteers. The size of the superficial FAZs were assessed by its area, length of perimeter, and Feret's diameter, and the shape by the circularity, axial ratio, roundness, and solidity. The correlations between each parameter and the clinical findings were statistically determined. The coefficients of variation (CV) of the parameters of FAZ size were higher than that of the parameters of FAZ shape. The refractive error and axial length were significantly correlated with area-related factors. The central macular thickness (CMT) was significantly correlated with all parameters. Although the CMT was a critical factor that was significantly correlated with the size and shape characteristics of the FAZ, the shape might be a better factor for characterizing the FAZ than the size because of the low CV of shape-related factors and the characteristics are less affected by the other ocular factors. 10.1038/s41598-018-28530-7
    REPRODUCIBILITY AND RELIABILITY OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FOR FOVEAL AVASCULAR ZONE EVALUATION AND MEASUREMENT IN DIFFERENT SETTINGS. La Spina Carlo,Carnevali Adriano,Marchese Alessandro,Querques Giuseppe,Bandello Francesco Retina (Philadelphia, Pa.) PURPOSE:Optical coherence tomography angiography (OCTA) allows delineating the foveal avascular zone (FAZ) easily and noninvasively. The present study aims to test reproducibility and reliability of FAZ evaluation by means of OCTA in different settings. METHODS:Twenty-four eyes of 24 normal subjects were investigated using AngioVue OCTA Imaging System. A series of OCTA acquisitions were taken both in basal and in different experimental settings after vasoactive stimuli. Images were evaluated separately by two operators and FAZ area was measured both manually and using the built-in automated measurement tool. RESULTS:No differences for FAZ area were found in the repetition of basal acquisitions, neither in manual nor in automated measurement (0.215 ± 0.06 vs. 0.216 ± 0.07, and 0.268 ± 0.05 vs. 0.264 ± 0.09, first vs. second basal measurement in square millimetres for manual and automated evaluation, P = 0.25 and P = 0.35, respectively). Interoperators correlation was optimal (r = 0.978 [95% CI 0.981-0.976]). No differences were found among the other settings, which included first basal and then repeated (second) in the morning, after flickering light stimulus, after a Bruce treadmill stress test, after 30 minutes dark adaptation, and basal in the evening, neither in automated nor in manual measurements. Automated measurements for nonflow areas provided significantly larger diameters than manual ones. CONCLUSION:AngioVue OCTA Imaging System produces highly reproducible FAZ images with a high interoperators concordance level. Optical coherence tomography angiography capability to detect FAZ area seems not to be influenced by any of the vasoactive stimuli considered in the current study. Nonflow areas seem to be larger when measured automatically than manually. 10.1097/IAE.0000000000001426
    Distributions of Radial Peripapillary Capillary Density and Correlations with Retinal Nerve Fiber Layer Thickness in Normal Subjects. Liu Guodong,Wang Yanliang,Gao Peng Medical science monitor : international medical journal of experimental and clinical research BACKGROUND The aim of this study was to investigate distribution rules of radial peripapillary capillaries (RPCs) density and correlations with retinal nerve fiber layers (RNFL) thickness in normal subjects. MATERIAL AND METHODS We included 78 eyes of 78 healthy subjects examined by optical coherence tomography angiography (OCTA). RPCs density and RNFL thickness were measured automatically. Distributions of RPCs density and RNFL thickness were analyzed at different locations. Correlations of these 2 parameters and relationship with large vessels were evaluated by Spearman test. RESULTS Average density for overall, peripapillary, and inside disc RCPs was 56.12±2.51%, 58.56±2.84%, and 60.16±4.01%, respectively. Overall and peripapillary RCPs density were positively correlated with RNFL thickness (r=0.595, P. 10.12659/MSM.933601
    Visualizing large choroidal blood flow by subtraction of the choriocapillaris projection artifacts in swept source optical coherence tomography angiography in normal eyes. Maruko Ichiro,Kawano Taizo,Arakawa Hisaya,Hasegawa Taiji,Iida Tomohiro Scientific reports Optical coherence tomography angiography (OCTA) seems not to image the choroidal blood flow pattern in the normal individual because of the OCT light attenuation. Our purpose in the current study was to visualize the large choroidal blood flow pattern after subtraction of the choriocapillaris projection artifact in normal eyes non-invasively by swept source (SS) OCTA. Sixty-one eyes of 45 individuals (19 men, 26 women) without ocular disease were examined by SS-OCTA (AngioPlex Elite 9000, Zeiss, Germany). A 12 × 12 mm macular area was scanned. Subfoveal choroidal thickness (SCT) was measured, and the choroidal blood flow pattern in a slab of 30 µm width at one-half of SCT was analyzed. In examining the choroidal blood flow pattern, a slab that was between 30 to 60 µm posterior to the retinal pigment epithelium, in which the choriocapillaris blood flow was most clearly imaged, was used for the subtraction of the projection artifacts from the choriocapillaris on the stromal area of choroid. The ratio (%) of the choroidal blood flow area in the whole choroidal region was calculated after binarization. Thirty-four eyes of 27 individuals (12 men, 15 women) were also examined by spectral domain OCTA (SD-OCTA). After the subtraction, the middle and large choroidal blood flow were clearly visible in SS-OCTA in all eyes. The mean SCT was 297 ± 61 µm, and the mean ratio of the choroidal blood flow area was 27.3 ± 8.2%, which was significantly correlated with SCT (R = 0.738, P < 0.01). SD-OCTA did not show the choroidal blood flow pattern. In conclusion, removal of the projection artifacts of choriocapillaris can make the choroidal blood flow visible in SS-OCTA of normal eyes. Because the ratio of choroidal blood flow area was correlated with SCT, the choroidal blood flow might be an important factor related to the choroidal thickness. 10.1038/s41598-018-34102-6
    Quantity and quality of image artifacts in optical coherence tomography angiography. Enders Christian,Lang Gabriele E,Dreyhaupt Jens,Loidl Max,Lang Gerhard K,Werner Jens U PloS one OBJECTIVE:To analyze quality and frequency of OCTA artifacts and to evaluate their impact on the interpretability of OCTA images. DESIGN:75 patients with diabetic retinopathy (DR), retinal artery occlusion (RAO), retinal vein occlusion (RVO), or neovascular age-related macular degeneration (nAMD) and healthy controls were enrolled in this cross-sectional study in the outpatient department of a tertiary eye care center. METHODS:All participants underwent an OCTA examination (spectral domain OCT Cirrus 5000 equipped with the AngioPlex module). OCTA scans were analyzed independently by two experienced ophthalmologists. Frequency of various artifacts for the entire OCTA scan and for different segmentation layers and the grading of OCTA interpretability were investigated. RESULTS:The analysis of 75 eyes of 38 women and 37 men between 24 and 94 years were included. Six eyes had no retinal disease, 19 eyes had nAMD, 16 had DR, 19 eyes had RVO, and 15 eyes showed RAO. A macular edema (ME) was present in 40 of the diseased eyes. Projection artifacts occurred in all eyes in any structure below the superficial retinal vessel layer, segmentation and motion artifacts were found in 55% (41/75) and 49% (37/75) of eyes, respectively. Other artifacts occurred less frequently. Segmentation artifacts were significantly more frequent in diseased than in healthy eyes (p<0.01). Qualitative assessment of OCTA images was graded as excellent in 65% and sufficient in 25% of cases, adding up to 91% images deemed acceptable for examination. Presence of ME was associated with a significantly poorer interpretability (p<0.01). CONCLUSION AND RELEVANCE:Various artifacts appear at different frequencies in OCTA images. Nevertheless, a qualitative assessment of the OCTA images is almost always possible. Good knowledge of possible artifacts and critical analysis of the complete OCTA dataset are essential for correct clinical interpretation and determining a precise clinical diagnosis. 10.1371/journal.pone.0210505
    Optical Coherence Tomography Angiography in Healthy Adult Subjects: Normative Values, Frequency, and Impact of Artifacts. Abu-Yaghi Nakhleh E,Obiedat Abdelrahman F,AlNawaiseh Tamara I,Hamad Ali M,Bani Ata Basil A,Quzli Ahmad A,AlRyalat Saif Aldeen BioMed research international Aim:This cross-sectional study is aimed at identifying normative ocular coherence tomography angiography (OCTA) values in a cohort of healthy adult Jordanian individuals and assessing the prevalence of different image artifacts and their impact on quantitative OCTA measurements. Materials and Methods:One hundred and eighty-one eyes from 100 healthy participants were included in this study. All participants underwent a comprehensive ophthalmological examination including best corrected visual acuity, slit lamp examination, and dilated fundoscopy. Swept-source OCTA images were obtained and analyzed for all 181 eyes. We recorded vascularity measurements and analyzed the prevalence and effect of ten different artifacts on superficial and deep retinal and choriocapillaris layer images. Results:Sixty-two percent of the participants were men ( = 62), and 38% ( = 38) were women. The age of participants ranged between 24 and 75 years (mean 50.5 ± 10.92). The mean central macular thickness was 237.71 (±22.905) m, and the mean choroidal thickness was 257.73 (±77.027) m. Artifacts were present in 46.4% of the acquired scans. Images with artifacts had higher mean age ( = 0.03), lower image quality ( < 0.001), higher central vascular density ( < 0.001), and lower inferior vascular density ( < 0.001) compared to artifact-free tomographs. Motion artifact was the most common type, which was present in 29 (16%) of images, followed by blink artifact 18 (9.9%), and Z offset 8 (4.4%). Conclusion:OCTA artifact detection and correction remains a challenging aspect of the diagnostic and follow-up process of patients with retinal pathologies. To our knowledge, this is the first study to examine the association between OCTA outputs and artifacts in healthy eyes. We report that in this cohort of normal individuals, images with artifacts had a significantly higher central vascular density (22.62 vs. 16.60) and a lower inferior vascular density (46.09 vs. 48.81). We also found that a significant increase in central vascular density is only present in images with Z offset artifact type (49.03). Motion artifact was the most common artifact seen in our series. However, we observed no alteration in quantitative parameters in images with motion artifacts. 10.1155/2022/7286252
    The volume of peripapillary vessels within the retinal nerve fibre layer: an optical coherence tomography angiography study of normal subjects. Allegrini Davide,Montesano Giovanni,Fogagnolo Paolo,Pece Alfredo,Riva Roberta,Romano Mario R,Rossetti Luca The British journal of ophthalmology BACKGROUND/AIMS:To investigate the contribution of vascular volume calculated by optical coherence tomography angiography (OCTA) to the measurement of peripapillary retinal nerve fibre layer (RNFL) thickness. METHODS:We used OCTA scans to build volumetric maps of the RNFL angiograms by thresholding the decorrelation images and summing the number of white pixels along the z-axis at each location. We used these maps to calculate the contribution of the vascular tissue to the RNFL thickness. RESULTS:We analysed 51 eyes from 36 subjects. The mean RNFL volume calculated on the peripapillary region was 0.607±0.045 mm and the mean vessel volume was 0.217±0.035 mm, with a mean vessel/total RNFL ratio of 35.627%±3.942%. When evaluated in the peripapillary circular section, the total contribution of the vascular tissue to the global RNFL thickness was 29.071%±3.945%. The superior and inferior sectors showed the highest percentage of vascular tissue within the RNFL circular profile (31.369% and 34.788% respectively). CONCLUSIONS:We found that the vascular contribution to the RNFL thickness is 29.07±3.945%. This is much higher than what has been reported from calculations made on the structural OCT alone (13% reported by Hood and 11.3%±1.6% for the Cirrus OCT and 11.8%±1.4% for the Spectralis OCT reported by Patel ). We conclude that evaluation of the vascular tissue contribution to the RNFL thickness with OCTA might be useful when performing precise quantification of the neuronal tissue. 10.1136/bjophthalmol-2017-310214
    The peripapillary retinal capillary density is highly correlated with its nerve fibre layer in normal population. Ding Xiaohu,Lu Lin,Yang Jing,Chen Yijiao,Ma Jin Clinical hemorheology and microcirculation PURPOSE:To explore the peripapillary capillary density distribution and its correlation with nerve fibre layer in superficial and deep retinal layers of healthy Chinese. METHODS:Images of superficial and deep retinal capillary networks were obtained by optical coherence tomography angiography (OCTA) using a CIRRUS TM HD-OCT Model 5000 system and analyzed by Image-Pro Plus (Medical Cybernetics, Version 6.0). Peripapillary capillary density was defined as the mean optical density of the annular region between two concentric circles of 3.085 mm and 3.835 mm diameter. Parafoveal capillary density was defined as the mean optical density between the foveal avascular zone (FAZ) boarder and a 2.5 mm diameter circle. Retinal nerve fibre layer (RNFL) thickness was also measured and the correlation with capillary density determined. RESULTS:Mean peripapillary capillary density was 4.16±1.06 in the superficial and 2.92±0.80 in the deep layer. Corresponding mean parafoveal densities were 2.65±0.55 and 2.51±0.55. Capillary densities were higher in the superficial layer of all quadrants for both peripapillary and parafoveal regions (P < 0.001). A significant correlation between peripapillary capillary density and RNFL thickness was found in the superficial layer (r = 0.305, P < 0.05). A negative correlation between age and capillary density was found in both peripapillary and parafoveal regions (P < 0.001). CONCLUSIONS:Peripapillary capillary density in the superficial layer highly correlated with RNFL thickness. Regional and age-related differences in peripapillary and parafoveal capillary density should be considered when diagnosing and monitoring individuals with diseases affecting retinal capillary density. 10.3233/CH-180453
    The Quantitative Measurements of Vascular Density and Flow Areas of Macula Using Optical Coherence Tomography Angiography in Normal Volunteers. Ghassemi Fariba,Fadakar Kaveh,Bazvand Fatemeh,Mirshahi Reza,Mohebbi Masoumeh,Sabour Siamak Ophthalmic surgery, lasers & imaging retina BACKGROUND AND OBJECTIVE:The quantification of the density of macular vascular networks and blood flow areas in the foveal and parafoveal area in healthy subjects using optical coherence tomography angiography (OCTA). PATIENTS AND METHODS:Cross-sectional, prospective study in an institutional setting at the Retina Services of Farabi Eye Hospital. One hundred twelve normal volunteers with no known ocular or systemic disease were included, including patient numbers (one or both eyes), selection procedures, inclusion/exclusion criteria, randomization procedure, and masking. En face angiogram OCTA was performed on a 3 mm × 3 mm region centered on the macula. Automated thresholding and measuring algorithm method for foveal and parafoveal blood flow and vascular density (VD) were used. The density of macular vascular networks and blood flow area in the foveal and parafoveal area were measured. RESULTS:A total of 224 healthy eyes from 112 subjects with a mean age of 36.4 years ± 11.3 years were included. In the foveal region, the VD of the superficial capillary network (sCN) was significantly higher than that of the deep capillary network (dCN) (31.1% ± 5.5% vs. 28.3% ± 7.2%; P < .001), whereas in the parafoveal area, VD was higher in the dCN (62.24% ± 2.8% vs. 56.5% ± 2.5%; P < .001). Flow area in the 1-mm radius circle in the sCN was less than in the dCN. Superficial foveal avascular zone (sFAZ) size was negatively correlated with the VD of the foveal sCN, but in the deep FAZ (dFAZ) was not correlated with VD or blood flow area of the fovea. There was no difference between measured VD and blood flow surface area in both eyes of the subjects. CONCLUSIONS:OCTA could be used as a noninvasive, repeatable, layer-free method in quantitative evaluation of VD and blood flow of macular area. The normal quantities of the vascular plexus density and flow will help in better understanding the pathophysiological basis of the vascular disease of retina. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:478-486.]. 10.3928/23258160-20170601-06
    Normative Data Assessment of Peripapillary and Macular Vessel Density and Foveal Avascular Zone Metrics Using Optical Coherence Tomography Angiography in Children. Kiziltoprak Hasan,Tekin Kemal,Cevik Seda,Kocer Ali Mert,Goker Yasin Sakir Journal of pediatric ophthalmology and strabismus PURPOSE:To quantify the vessel density of the macula and optic disc and foveal avascular zone (FAZ) in healthy children and to evaluate the effects of age, gender, axial length, body mass index (BMI), and refractive errors on vessel density and FAZ. METHODS:This study enrolled 92 eyes of 92 participants (42 boys and 50 girls). Optical coherence tomography angiography (OCTA) was performed using AngioVue (Avanti; Optivue). FAZ area, nonflow area, superficial and deep vessel density, FAZ perimeter, acircularity index of FAZ, foveal density, and radial peripapillary capillary vessel density were analyzed by gender. Correlations between the investigated OCTA parameters and age, axial length, and BMI were evaluated. RESULTS:Girls had significantly larger nonflow and FAZ area than boys (P = .01 and .02). Superficial and deep vessel density at the fovea was significantly higher in boys compared to girls (P = .01 and .03). Inferior temporal and superior temporal Radial peripapillary capillary vessel densities were significantly higher in girls than boys (P = .01 and .03). No significant difference was found in the macular and optic disc vessel density measurements within refractive groups (P > .05, for all). Regarding the correlation of age with FAZ and vessel density parameters, only nonflow area was positively correlated with age (r = 0.22, P = .03). CONCLUSIONS:This study provides normative data for children. Although boys had greater foveal vessel density, girls had greater FAZ area and nonflow area. Refractive status of the eye and BMI did not influence the OCTA parameters. Although nonflow area was positively correlated with age, other parameters were steady within the ages of 7 to 18 years. [J Pediatr Ophthalmol Strabismus. 2020;57(6):388-398.]. 10.3928/01913913-20200903-01
    Optical coherence tomography angiography in primary eye care. Coffey Alexandra M,Hutton Emily K,Combe Louise,Bhindi Pooja,Gertig Demi,Constable Paul A Clinical & experimental optometry Optical coherence tomography angiography (OCT-A) is a non-invasive imaging modality for assessing the vasculature within ocular structures including the retina, macula, choroid and optic nerve. OCT-A has a wide range of clinical applications in various optometric conditions which have been independently reported in the literature. This paper aims to present a review of the current literature on the clinical application of OCT-A in optometric practice as well as to analyse and evaluate the quality of the available evidence. This review included 78 articles from a literature search conducted on 26 May 2019 across the following databases: Cochrane Library of Systematic Reviews, Medline, Scopus and Web of Science. Primary ocular pathologies discussed in this review include glaucoma, diabetic retinopathy, age-related macular degeneration, myopia, acquired and congenital macular dystrophies, epiretinal membrane, retinal vein occlusion, retinitis pigmentosa, choroidal melanoma, uveitis, central serous chorioretinopathy, amblyopia and optic neuropathies. Primary outcome variables included vessel density, foveal avascular zone area and diameter, flow velocity and flow index. This review aims to evaluate the evidence available for OCT-A applications in diagnosis and prognosis of ocular conditions in an optometric setting. 10.1111/cxo.13068
    Evaluation of the Optic Disc and Macula in Healthy Children Using Optical Coherence Tomography Angiography İçel Erel,Yılmaz Hayati,Uçak Turgay,Taşlı Nurdan Gamze,Uğurlu Adem,Karakurt Yücel Turkish journal of ophthalmology Objectives:To perform the measurements of the optic disc and macula in healthy children using optical coherence tomography angiography (OCTA) in order to determine the normative data values and compare these by age, gender, spherical equivalent (SE), and axial length (AL). Materials and Methods:A total of 146 eyes belonging to 146 healthy children (74 girls, 72 boys) aged 6 to 16 years were included in this prospective study. Refraction and biometry measurements were performed. Retinal nerve fiber layer thickness (RNFLT), central macular volume, and central macular thickness (CMT) were measured by optical coherence tomography (OCT) after dilatation. Using the OCTA device, foveal avascular zone (FAZ) area, vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the macula, and the VD of the radial peripapillary capillary plexus (RPCP) of the optic disc were recorded. Results:The mean age of the study group was 11.27±3 years, the mean AL was 23.39±1.18 mm and the mean SE was -1.31±1.61 diopters. The mean FAZ area was 0.3±0.09 mm2, the mean SCP-VD was 43.88±3.4%, the mean DCP-VD was 39.6±3.55%, and the mean RPCP-VD was 52.47±3.42%. When the relationship between the OCTA measurements and the SE and AL values were analyzed, there was no statistical significance (p>0.05). When age and OCTA measurements were compared, only DCP-VD values were found to significantly decrease with increasing age (p=0.015). There was no significant difference in OCTA measurements based on gender (p>0.05). Similarly, no statistical age-based differences were observed in RNFLT, CMV and CMT values (p>0.05). Conclusion:With its short procedure time and no dye requirement, OCTA can be safely used in the evaluation of the optic disc and macular perfusion in children. Determination of normative values in children will be useful in detecting pathologic changes in tissue in patients with retinal diseases. 10.4274/tjo.galenos.2020.85282
    Optical Coherence Tomography Angiography of the Peripapillary Retina in Normal-Tension Glaucoma and Chronic Nonarteritic Anterior Ischemic Optic Neuropathy. Mastropasqua Rodolfo,Agnifili Luca,Borrelli Enrico,Fasanella Vincenzo,Brescia Lorenza,Di Antonio Luca,Mastropasqua Leonardo Current eye research PURPOSE:To analyze the retinal radial peripapillary capillary (RPC) network in normal-tension glaucoma (NTG) and nonarteritic anterior ischemic optic neuropathy (NAION) eyes using optical coherence tomography angiography (OCTA). MATERIAL AND METHODS:Twenty-two patients with NTG, 22 patients with unilateral chronic NAION, and 23 age-matched controls were enrolled. Patients underwent OCTA to obtain en face angiograms of the peripapillary region. The main outcome measures were as follows: (1) the whole en face image perfusion density (WPD) and (2) the circumpapillary perfusion density (CPD). RESULTS:Mean ± SD age was 66.3 ± 7.0 years in the NTG group, 68.1 ± 4.3 years in the NAION group, and 63.9 ± 7.0 years in the control group (p > 0.05 for all the comparisons). The visual field mean defect (MD) was worse in patients than in controls (p < 0.0001), but did not differ between NTG and NAION (-9.6 ± 2.6 dB and -8.2 ± 2.6 dB, respectively). The WPD was 0.41 ± 0.04 in the NTG group (p < 0.0001 in comparison with healthy subjects and NAION patients), 0.46 ± 0.04 in the NAION group (p < 0.0001 in comparison with the control group), and 0.56 ± 0.03 in the control group. The CPD was significantly reduced in both NTG (0.48 ± 0.04, p < 0.0001) and NAION eyes (0.52 ± 0.05, p < 0.0001), after comparison to control eyes (0.59 ± 0.03). Moreover, the CPD was significantly lower in NTG than in NAION eyes (p = 0.006). CONCLUSIONS:OCTA documented a reduction of the peripapillary perfusion in NTG and unilateral NAION. In presence of similar functional damage, the lower perfusion densities in NTG may indicate greater vascular alterations in chronic compared to acute ischemic optic neuropathies. 10.1080/02713683.2018.1438630
    Repeatability and Reproducibility of Foveal Avascular Zone Area Measurement on Normal Eyes by Different Optical Coherence Tomography Angiography Instruments. Pilotto Elisabetta,Frizziero Luisa,Crepaldi Anna,Della Dora Enrico,Deganello Davide,Longhin Evelyn,Convento Enrica,Parrozzani Raffaele,Midena Edoardo Ophthalmic research PURPOSE:To compare the foveal avascular zone (FAZ) area measurements produced by different optical coherence tomography angiography (OCTA). METHODS:Healthy enrolled volunteers underwent OCTA using 2 different devices: Spectralis HRA+OCTA (Heidelberg Engineering, Heidelberg, Germany) and RS-3000 Advance (Nidek, Gamagori, Japan). Two graders measured FAZ in both superficial (SCP) and deep (DCP) retinal capillary plexuses. The SCP and DCP en face images were visualized automatically segmenting 2 separate slabs defined by the arbitrary segmentation lines created by the software of each OCT device. One grader repeated each measure twice. RESULTS:Fifty-nine eyes were included. The mean FAZ was 0.33 ± 0.09 mm2 at the SCP and 0.57 ± 0.17 mm2 at the DCP measured with RS-3000 versus 0.30 ± 0.08 and 0.35 ± 0.08 mm2, respectively, measured with Spectralis. The measurements of the 2 devices were significantly different (p < 0.0001). The intraoperator agreement was excellent at the SCP (intraclass correlation coefficient, ICC: 0.97 with Spectralis and 0.96 with RS-3000). At the DCP, it was good with Spectralis and fair with RS-3000 (ICC: 0.85 and 0.64, respectively). The interoperator agreement was excellent for Spectralis and good for RS-3000 at the SCP (ICC: 0.97 and 0.93, respectively). It was good at the DCP with both devices (ICC: 0.74 with RS-3000 and 0.81 with Spectralis). CONCLUSIONS:FAZ measurements obtained with different OCTA devices differ. These findings should be considered in follow-up studies of patients with retinal vascular diseases. 10.1159/000485463
    Optical coherence tomography angiography in patients with retinitis pigmentosa who have normal visual acuity. Takagi Seiji,Hirami Yasuhiko,Takahashi Masayo,Fujihara Masashi,Mandai Michiko,Miyakoshi Chisato,Tomita Goji,Kurimoto Yasuo Acta ophthalmologica PURPOSE:To investigate flow area changes measured using optical coherence tomography angiography (OCTA; RTVue XR Avanti ) in patients with retinitis pigmentosa (RP) with preserved visual acuity (VA). METHODS:This was an age- and refraction-matched case-control study. Consecutive patients with a best-corrected visual acuity (BCVA) of ≥20/20 and normal subjects were recruited. Fifty eyes (32 patients) and 22 eyes (12 controls) were included. The flow area and foveal avascular zone (FAZ) were measured in both superficial and deep layers within a 3 × 3 mm central area of the fovea. Association between OCTA parameters and the length of the inner segment ellipsoid (ISe) and external limiting membrane (ELM), the area without abnormal fluorescence in fundus autofluorescence (normal FAF area ratio) and the area of I-2e of the Goldmann perimeter were analysed using mixed-effects regression analysis. RESULTS:Foveal avascular zones were significantly smaller in patients with RP than in controls in superficial (p = 0.004) but not in deep layers (p = 0.25). The flow area in superficial (p = 0.007) and deep layers (p = 0.004) was significantly smaller in patients with RP than in controls. In patients with RP, flow areas in the superficial layers, but not in the deep layers, were significantly associated with the lengths of ISe (p = 0.001) and ELM (p = 0.002) and the I-2e area (p = 0.036), but not with the normal FAF area ratio (p = 0.399). CONCLUSION:Optical coherence tomography angiography (OCTA)-measured flow area in superficial layers gradually reduced with RP progression and may be a useful parameter of RP pathogenesis. 10.1111/aos.13680
    Morphometry of the normal retinal periarteral capillary-free zone and changes during severe nonproliferative diabetic retinopathy. Li H,Ding X,Lu L,Yang J,Ma J Clinical hemorheology and microcirculation PURPOSE:To explore the normal morphological features of the retinal periarteral capillary free zone (paCFZ) and the changes associated with severe non-proliferative diabetic retinopathy (NPDR) by optical coherence tomography angiography (OCTA). METHODS:A total of 148 normal subjects and 115 patients with severe NPDR were enrolled. Spectral-domain OCTA was used to acquire the image with a Cirrus prototype. Diameter and area of each paCFZ quadrant and adjacent large artery diameter was estimated. RESULTS:In healthy subjects, the maximum width of paCFZ in the temporal quadrant (169.38 ± 19.26 μm) was smaller than the other three quadrants (all P <0.001). The ratio of maximum paCFZ width to artery caliber was much larger in the nasal quadrants than the rest quadrants (Ps <0.05). In patients with severe NPDR, both maximum width and area of paCFZ were significant larger, and the retinal artery inner diameters significant smaller in each quadrant compared to normal subjects (Ps <0.05). The ratio of paCFZ maximum width to artery caliber maximum width was significant greater, and the ratio of paCFZ area to artery caliber was significantly higher in all quadrants compared to normal eyes (Ps <0.05). CONCLUSIONS:OCTA provides noninvasive and quantitative measurement of paCFZ dimensions. The maximum width and area of paCFZ quadrants and the ratios of these parameters to adjacent inner artery width and area are elevated in severe NPDR, suggesting that changes in paCFZ dimension can be used as clinical indices for diseases associated with changes in retinal microcirculation and oxygen pressure.PRÉCIS:Optical coherence tomography angiography revealed differences in retinal periarteral capillary free zone (paCFZ) morphometry between health retina and severe non-proliferative diabetic retinopathy. Morphometric indices of paCFZ may be useful for monitoring disease occurrence and progression. 10.3233/CH-180458
    Quantitative comparisons between optical coherence tomography angiography and matched histology in the human eye. An Dong,Balaratnasingam Chandrakumar,Heisler Morgan,Francke Ashley,Ju MyeongJin,McAllister Ian L,Sarunic Marinko,Yu Dao-Yi Experimental eye research The aim was to quantitatively compare retinal vascular detail as seen on optical coherence tomography angiography (OCTA) and matched histology in the human eye. 13 normal human donor eyes were used. The central retinal artery was cannulated after which human packed red blood cells were perfused through the retinal vasculature. Retinal vessels were imaged using a custom-built OCTA device during red blood cell perfusion. The eye was subsequently perfused with endothelial cell antibodies and the flat-mounted retina studied histologically using a confocal scanning laser microscope. Qualitative and quantitative comparisons of retinal vascular information as seen on OCTA and histology from the same region of interest were performed. Gradable OCTA images were acquired from 4 of 13 eyes with mean postmortem-to-OCTA imaging time of 4.5 ± 1.3 h 23 pairs of OCTA-histology matched images were evaluated. The retinal arteries and veins had similar pixel intensity on OCTA images. The diameter of retinal veins was significantly greater than its paired artery on OCTA (P < 0.001). The density of vascular structures on OCTA (40.2% ± 10.1%) was significantly less than matched histology (52.1% ± 9.3%, P < 0.001). Mean capillary diameter on OCTA (10.2 ± 2.4 μm) was significantly greater than histology (8.2 ± 2.4 μm; P < 0.001). This is the first study to directly compare OCTA against histology from the same human eye. OCTA visualizes many of the vascular structures in the human retinal circulation but does not exactly match what is seen on histologic examination. 10.1016/j.exer.2018.02.006
    Microvascular Changes in Peripapillary and Optic Nerve Head Tissues After Trabeculectomy in Primary Open-Angle Glaucoma. Kim Ji-Ah,Kim Tae-Woo,Lee Eun Ji,Girard Michaël J A,Mari Jean Martial Investigative ophthalmology & visual science Purpose:To determine microvasculature changes in the deep optic nerve head (ONH) and peripapillary tissues after trabeculectomy, and to correlate these with changes in the lamina cribrosa (LC) curvature. Methods:Fifty-six eyes with primary open-angle glaucoma that underwent trabeculectomy were included. The optic nerve and peripapillary microvasculature were evaluated in en face images obtained using optical coherence tomography (OCT) angiography (OCTA) before and 3 months after trabeculectomy. The OCTA-derived vessel density (VD) was calculated in each layer segmented into the prelaminar tissue (PLT), LC, peripapillary retina (PR), and peripapillary choroid (PPC). Swept-source OCT volume scanning of ONH was performed on the same day as OCTA to examine the change in LC curvature quantified as the LC curve index (LCCI). Results:At 3 months postoperative, the IOP and LCCI had significantly decreased (both P < 0.001). OCTA images revealed a significant increase in VD in the LC (P = 0.006), but not in the PLT, PR, or PPC. Twenty-six eyes showed both significant LCCI decrease and VD increase based on 95% Bland-Altman limits of agreement. The VD increase in the LC was significantly associated with larger percentage reductions in IOP (P = 0.040) and LCCI (P < 0.001) in the univariate analysis. Multivariate analysis revealed that only the LCCI reduction was a significant factor affecting the VD increase in the LC. Conclusions:A significant increase in VD was observed at the level of the LC after trabeculectomy. The VD increase was more strongly associated with the reduction in the LC curvature than with the reduction of IOP. 10.1167/iovs.18-25038
    The Effect of Software Versions on the Measurement of Retinal Vascular Densities Using Optical Coherence Tomography Angiography. Wang Huijuan,Hu Huiling,Gregori Giovanni,Zhang Juan,Jiang Hong,Wang Jianhua Current eye research BACKGROUND:The goal of the study was to determine the effect of different software versions on the measurement of retinal vessel densities using optical coherence tomography angiography (OCTA) in normal subjects. METHODS:Thirty-two eyes of eighteen healthy subjects were imaged using two OCTA devices: the Optovue RTVue and the Zeiss Cirrus. The macular 3 × 3 mm scan protocol was used. The images acquired using the Optovue OCTA device were exported using two different software versions in the system and compared to the images acquired through the Zeiss OCTA. In addition, the Optovue OCTA images were exported after manual adjustment of the segmentation boundaries according to the intraretinal layer definition. The densities of the superficial vascular plexus (SVP) and deep vascular plexus (DVP) were measured using fractal analysis by box-counting (Dbox). RESULTS:Both the vessel densities of the SVP and DVP acquired using the Optovue OCTA device were significantly different when compared to those from the Zeiss OCTA device (all, <.05). No significant difference was found between the vessel densities of the SVP exported using both the new and old versions of Optovue ( >.05). However, the DVP exported using the new Optovue software version was significantly different compared to those exported using the old version ( <.05). The vessel densities of the SVP and DVP were related among the Optovue OCTA software versions and manual adjustment method (r ranged from 0.55 to 0.77; all <.05). CONCLUSION:This is the first study to determine that different software versions with various intraretinal layer segmentation methods affect the vessel density measurements of the SVP and DVP. 10.1080/02713683.2020.1801756
    OCT Angiography Biomarkers for Predicting Visual Outcomes after Ranibizumab Treatment for Diabetic Macular Edema. Ophthalmology. Retina PURPOSE:To correlate quantitative OCT angiography (OCTA) biomarkers with clinical features and to predict the extent of visual improvement after ranibizumab treatment for diabetic macular edema (DME) with OCTA biomarkers. DESIGN:Retrospective, longitudinal study in Taiwan. PARTICIPANTS:Fifty eyes of 50 patients with DME and 22 eyes of 22 healthy persons, with the exception of cataract and refractive error, from 1 hospital. METHODS:Each eye underwent OCT angiography (RTVue XR Avanti System with AngioVue software version 2017.1; Optovue, Fremont, CA), and 3×3-mm en face OCTA images of the superficial layer and the deep layer were obtained at baseline and after 3 monthly injections of ranibizumab in the study group. OCT angiography images also were acquired from the control group. MAIN OUTCOME MEASURES:Five OCTA biomarkers, including foveal avascular zone (FAZ) area (FAZ-A), FAZ contour irregularity (FAZ-CI), average vessel caliber (AVC), vessel tortuosity (VT), and vessel density (VD), were analyzed comprehensively. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) also were obtained. Student t tests were used to compare the OCTA biomarkers between the study group and the control group. Linear regression models were used to evaluate the correlations between the baseline OCTA biomarkers and the changes of BCVA and CRT after treatment. RESULTS:Eyes with DME had larger AVC, VT, FAZ-A, and FAZ-CI and lower VD than those in the control group (P < 0.001 for all). After the loading ranibizumab treatment, these OCTA biomarkers improved but did not return to normal levels. Among all biomarkers, higher inner parafoveal VD in the superficial layer at baseline correlated most significantly with visual gain after treatment in the multiple regression model with adjustment for CRT and ellipsoid zone disruption (P < 0.001). To predict visual improvement, outer parafoveal VD in the superficial layer at the baseline showed the largest area under the receiver operating characteristic curve (0.787; P = 0.004). No baseline OCTA biomarkers showed any significant correlation specifically with anatomic improvement. CONCLUSIONS:For eyes with DME, parafoveal VD in the superficial layer at baseline was an independent predictor for visual improvement after the loading ranibizumab treatment. 10.1016/j.oret.2019.04.027
    Select Features of Diabetic Retinopathy on Swept-Source Optical Coherence Tomographic Angiography Compared With Fluorescein Angiography and Normal Eyes. Salz David A,de Carlo Talisa E,Adhi Mehreen,Moult Eric,Choi WhooJhon,Baumal Caroline R,Witkin Andre J,Duker Jay S,Fujimoto James G,Waheed Nadia K JAMA ophthalmology IMPORTANCE:Optical coherence tomographic angiography (OCTA) is a recently developed noninvasive imaging technique that can visualize the retinal and choroidal microvasculature without the injection of exogenous dyes. OBJECTIVE:To evaluate the potential clinical utility of OCTA using a prototype swept-source OCT (SS-OCT) device and compare it with fluorescein angiography (FA) for analysis of the retinal microvasculature in diabetic retinopathy. DESIGN, SETTING, AND PARTICIPANTS:Prospective, observational cross-sectional study conducted at a tertiary care academic retina practice from November 2013 through November 2014. A cohort of diabetic and normal control eyes were imaged with a prototype SS-OCT system. The stage of diabetic retinopathy was determined by clinical examination. Imaging was performed using angiographic 3 × 3-mm and 6 × 6-mm SS-OCT scans to generate 3-dimensional en-face OCT angiograms for each eye. Two trained Boston Image Reading Center readers reviewed and graded FA and OCTA images independently. MAIN OUTCOMES AND MEASURES:The size of the foveal nonflow zone and the perifoveal intercapillary area on OCTA were measured in both normal and diabetic eyes using Boston Image Reading Center image analysis software. RESULTS:The study included 30 patients with diabetes (mean [SD] age, 55.7 [10] years) and 6 control individuals (mean [SD] age, 55.1 [6.4] years). A total of 43 diabetic and 11 normal control eyes were evaluated with OCTA. Fluorescein angiography was performed in 17 of 43 diabetic eyes within 8 weeks of the OCTA. Optical coherence tomographic angiography was able to identify a mean (SD) of 6.4 (4.0) microaneurysms (95% CI, 4.4-8.5), while FA identified a mean (SD) of 10 (6.9) microaneurysms (95% CI, 6.4-13.5). The exact intraretinal depth of microaneurysms on OCTA was localized in all cases (100%). The sensitivity of OCTA in detecting microaneuryms when compared with FA was 85% (95% CI, 53-97), while the specificity was 75% (95% CI, 21-98). The positive predictive value and the negative predictive value were 91% (95% CI, 59-99) and 60% (95% CI, 17-92), respectively. CONCLUSIONS AND RELEVANCE:Optical coherence tomographic angiography enables noninvasive visualization of macular microvascular pathology in eyes with diabetic retinopathy. It identified fewer microaneurysms than FA, but located their exact intraretinal depth. Optical coherence tomographic angiography also allowed the precise and reproducible delineation of the foveal nonflow zone and perifoveal intercapillary area. Evaluation of OCTA may be of clinical utility in the evaluation and grading of diabetic eye disease. 10.1001/jamaophthalmol.2016.0600
    Evaluation of microvascular network with optical coherence tomography angiography (OCTA) in branch retinal vein occlusion (BRVO). Chen Lulu,Yuan Mingzhen,Sun Lu,Wang Yuelin,Chen Youxin BMC ophthalmology BACKGROUND:To evaluate changes of microvascular network of macular and peripapillary regions and to provide a quantitative measurement of foveal avascular zone (FAZ) in unilateral BRVO patients. METHODS:Forty-seven unilateral BRVO patients and forty-seven normal controls were enrolled. A 3*3 mm scan centered on fovea followed by a 4.5*4.5 mm scan centered on optic nerve head (ONH) were obtained in BRVO eyes, fellow eyes and control eyes of each individual using OCTA (Optovue Inc., Fremont, CA, USA). Vessel density (VD) in superficial (SVC) and deep vascular complex (DVC) of macula and radial peripapillary capillary (RPC) were automatically calculated. Parameters of FAZ region including size, perimeter, acircularity index (AI) and foveal vessel density 300 (FD-300) were measured. RESULTS:VDs of SCV and DVC were significantly lower, especially in affected regions, in BRVO eyes compared with fellow eyes (P < 0.05). BRVO affected eyes has larger FAZ size, FAZ perimeter, AI and lower FD-300 compared with fellow eyes (all P < 0.05). VD of SVC and FD-300 were lower in fellow eyes compared with normal control eyes (P < 0.05). The average vessel density in whole area and peripapillary area in BRVO eyes were significantly lower compared with fellow eyes (P < 0.05). VD of inside disc in fellow eyes was lower than normal eyes (P < 0.05). CONCLUSIONS:OCTA provided quantitative information of vascular changes in BRVO. FAZ in BRVO eyes showed significant morphological alterations and decreases of VD in surrounding area. Decreases of VD existed not only in SVC and DVC in macular region but also in RPCs in BRVO eyes. Unaffected eyes of unilateral BRVO showed vascular abnormalities in superficial retinal layer, peri-FAZ area and also peripapillary regions. 10.1186/s12886-020-01405-0
    Use of OCTA Capillary Perfusion Density Measurements to Detect and Grade Macular Ischemia. Babiuch Amy S,Uchida Atsuro,Hu Ming,Khan Mehnaz,Srivastava Sunil K,Singh Rishi P,Kaiser Peter K,Rachtiskaya Aleksandra,Reese Jamie L,Ehlers Justis P Ophthalmic surgery, lasers & imaging retina BACKGROUND AND OBJECTIVE:To compare optical coherence tomography angiography (OCTA) capillary perfusion density (CPD) measurements of normal eyes and eyes with macular ischemia (MI). PATIENTS AND METHODS:AVATAR is an institutional review board-approved, prospective, observational imaging study using the Avanti RTVue XR HD. OCTA reports were reviewed for the presence of MI. Qualitative MI grading was performed, and CPD metrics in the superficial and deep fovea and parafovea were analyzed. A normal eye cohort was identified for comparative assessment. RESULTS:The MI and normal cohorts included 55 and 58 eyes, respectively. Compared to normal eyes, eyes with MI had significantly lower CPD values in all regions. There was a statistically significant correlation between qualitative MI grade and VA in the superficial (P = .003) and deep plexuses (P = .029). Only deep parafoveal CPD values demonstrated correlation with VA (P = .043). CONCLUSIONS:Eyes with MI determined by masked qualitative OCTA grading demonstrated significantly reduced CPD values compared to normal eyes. Categorical assessment of MI severity correlated with VA. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S30-S36.]. 10.3928/23258160-20200401-04
    Peripapillary perfused capillary density in true versus pseudoexfoliation syndrome: An OCTA study. Tangtammaruk Phantaraporn,Petpiroon Purit,Supakonatanasan Wasu,Teekhasaenee Chaiwat,Suwan Yanin PloS one PURPOSE:To compare peripapillary perfused capillary density (PCD) among eyes with true exfoliation syndrome (TEX), eyes with pseudoexfoliation syndrome (PEX), and healthy control eyes. MATERIALS AND METHODS:In this observational cross-sectional study, eyes with and without TEX or PEX were assessed by optical coherence tomography angiography (OCTA) imaging. Bilateral OCTA images (4.5 × 4.5 mm2) centered at the optic nerve head were obtained using a commercial spectral domain OCTA system. Optic nerve head perfusion was quantified using the split-spectrum amplitude decorrelation angiography algorithm. Categorical and continuous variables were compared using the chi-squared test and one-way analysis of variance, respectively. The generalized estimating equation was used to adjust for confounding factors and determine inter-ocular associations. RESULTS:We enrolled 39 eyes with TEX, 31 eyes with PEX, and 32 control eyes. There were no significant differences among the three groups regarding age, intraocular pressure, cup-to-disc ratio, blood pressure, or axial length (all p>0.05). There were significant differences in global PCD among the three groups (p = 0.01). There were significant differences in annular PCD between the TEX and PEX groups (p = 0.027). CONCLUSIONS:While both global and annular PCDs did not differ between the TEX and control groups, greater loss of annular PCD in the PEX group than in the TEX and control groups suggests more pronounced microvascular disturbance in PEX. SYNOPSIS/PRECIS:Greater microvascular attenuation in PEX compared with TEX and normal control measured by OCTA. 10.1371/journal.pone.0239109
    Optical coherence tomography angiography of normal skin and inflammatory dermatologic conditions. Deegan Anthony J,Talebi-Liasi Faezeh,Song Shaozhen,Li Yuandong,Xu Jingjiang,Men Shaojie,Shinohara Michi M,Flowers Mary E,Lee Stephanie J,Wang Ruikang K Lasers in surgery and medicine BACKGROUND:In clinical dermatology, the identification of subsurface vascular and structural features known to be associated with numerous cutaneous pathologies remains challenging without the use of invasive diagnostic tools. OBJECTIVE:To present an advanced optical coherence tomography angiography (OCTA) method to directly visualize capillary-level vascular and structural features within skin in vivo. METHODS:An advanced OCTA system with a 1310 nm wavelength was used to image the microvascular and structural features of various skin conditions. Subjects were enrolled and OCTA imaging was performed with a field of view of approximately 10 × 10 mm. Skin blood flow was identified using an optical microangiography (OMAG) algorithm. Depth-resolved microvascular networks and structural features were derived from segmented volume scans, representing tissue slabs of 0-132, 132-330, and 330-924 μm, measured from the surface of the skin. RESULTS:Subjects with both healthy and pathological conditions, such as benign skin lesions, psoriasis, chronic graft-versus-host-disease (cGvHD), and scleroderma, were OCTA scanned. Our OCTA results detailed variations in vascularization and local anatomical characteristics, for example, depth-dependent vascular, and structural alterations in psoriatic skin, alongside their resolve over time; vascular density changes and distribution irregularities, together with corresponding structural depositions in the skin of cGvHD patients; and vascular abnormalities in the nail folds of a patient with scleroderma. CONCLUSION:OCTA can image capillary blood flow and structural features within skin in vivo, which has the potential to provide new insights into the pathophysiology, as well as dynamic changes of skin diseases, valuable for diagnoses, and non-invasive monitoring of disease progression and treatment. Lasers Surg. Med. 50:183-193, 2018. © 2018 Wiley Periodicals, Inc. 10.1002/lsm.22788
    Microvascular Changes in the Choriocapillaris of Diabetic Patients Without Retinopathy Investigated by Swept-Source OCT Angiography. Dai Yining,Zhou Hao,Chu Zhongdi,Zhang Qinqin,Chao Jennifer R,Rezaei Kasra A,Wang Ruikang K Investigative ophthalmology & visual science Purpose:To investigate the microvascular changes in macular retina and choriocapillaris (CC) in diabetic eyes without retinopathy using swept-source optical coherence tomography angiography (SS-OCTA). Methods:A commercial SS-OCTA system was used to collect 6 × 6-mm macular scans from patients. Three depth-resolved retinal slabs and a CC slab were segmented by a validated semiautomated algorithm. Retinal vessel area density, vessel skeleton density, and nonperfusion area were calculated on segmented retinal slabs. Foveal avascular zone was automatically measured based on en face image of the whole retinal layer. For CC quantification, the percentage of flow deficits (FD%) and the flow deficit (FD) sizes were measured. Results:Sixteen eyes from 16 diabetic patients without clinically detectable retinopathy and 16 eyes from 16 age-matched nondiabetic controls were included. There was no significant difference between the two groups in all retinal vessel quantitative parameters (all P > 0.05). However, the mean FD% and mean FD sizes were significantly increased in CC in the central 1.0-mm disk (P = 0.011 and P = 0.017, respectively), the central 1.5-mm rim (P = 0.003 and P = 0.009, respectively), the central 2.5-mm rim (P = 0.018 and P = 0.020, respectively), and the entire 5.0-mm disk (P = 0.009 and P = 0.008, respectively) in diabetic eyes compared with controls. Conclusions:CC perfusion in the macula is decreased in diabetic patients without retinopathy as compared to age-matched normal controls. Decreased CC perfusion in the macula may be an early indicator of otherwise clinically undetectable diabetic vasculopathy. 10.1167/iovs.61.3.50
    Optical Coherence Tomography Angiography of the Peripapillary Retina in Glaucoma. Liu Liang,Jia Yali,Takusagawa Hana L,Pechauer Alex D,Edmunds Beth,Lombardi Lorinna,Davis Ellen,Morrison John C,Huang David JAMA ophthalmology IMPORTANCE:Vascular factors may have important roles in the pathophysiology of glaucoma. A practical method for the clinical evaluation of ocular perfusion is needed to improve glaucoma management. OBJECTIVE:To detect peripapillary retinal perfusion in glaucomatous eyes compared with normal eyes using optical coherence tomography (OCT) angiography. DESIGN, SETTING, AND PARTICIPANTS:Prospective observational study performed from July 24, 2013, to April 17, 2014. Participants were recruited and tested at Casey Eye Institute, Oregon Health & Science University. In total, 12 glaucomatous eyes and 12 age-matched normal eyes were analyzed. The optic disc region was imaged twice using a 3 × 3-mm scan by a 70-kHz, 840-nm-wavelength spectral OCT system. The split-spectrum amplitude-decorrelation angiography algorithm was used. Peripapillary flow index was calculated as the mean decorrelation value in the peripapillary region, defined as a 700-µm-wide elliptical annulus around the disc. Peripapillary vessel density was the percentage area occupied by vessels. The data statistical analysis was performed from October 30, 2013, to May 30, 2014. MAIN OUTCOMES AND MEASURES:Variability was assessed by the coefficient of variation. The Mann-Whitney test was used to compare the 2 groups of eyes. Correlations between vascular and visual field variables were assessed by linear regression analysis. RESULTS:In 12 normal eyes, a dense microvascular network around the disc was visible on OCT angiography. In 12 glaucomatous eyes, this network was visibly attenuated globally and focally. In normal eyes, between-visit reproducibilities of peripapillary flow index and peripapillary vessel density were 4.3% and 2.7% of the coefficient of variation, respectively, while the population variabilities of peripapillary flow index and peripapillary vessel density were 8.2% and 3.0% of the coefficient of variation, respectively. Peripapillary flow index and peripapillary vessel density in glaucomatous eyes were lower than those in normal eyes (P < .001 for both). Peripapillary flow index (Pearson r = -0.808) and peripapillary vessel density (Pearson r = -0.835) were highly correlated with visual field pattern standard deviation in glaucomatous eyes (P = .001 for both). The areas under the receiver operating characteristic curve for normal vs glaucomatous eyes were 0.892 for peripapillary flow index and 0.938 for peripapillary vessel density. CONCLUSIONS AND RELEVANCE:Using OCT angiography, reduced peripapillary retinal perfusion in glaucomatous eyes can be visualized as focal defects and quantified as peripapillary flow index and peripapillary vessel density, with high repeatability and reproducibility. Quantitative OCT angiography may have value in future studies to determine its potential usefulness in glaucoma evaluation. 10.1001/jamaophthalmol.2015.2225