Comparative study between swept-source and spectraldomain OCTA for imaging of choroidal neovascularization in age-related macular degeneration

AIM:To compare the dif ferences of choroidal neovascularization(CNV)measurements between sweptsource and spectral-domain optical coherence tomography angiography(SS-OCTA and SD-OCTA)in neovascular agerelated macular degeneration(nAMD)and the imaging reliability of the two devices.METHODS:Prospective comparative study.SS-OCTA and SD-OCTA were used to scan the same eye with the modes of 3×3 and 6×6 mm2 centered on the neovascularization.Only qualified images were chosen and the border of CNV was manually delineated by two graders independently.The area of CNV(ACNV),vascular perfusion density(PD),and vessel length density(VLD)within the delineation were calculated using Image J.The differences of CNV measurements between the two OCTA devices were compared using Bland-Altman analysis.The agreement between the two graders on the measurements of each device was compared using the intraclass correlation coefficient(ICC).RESULTS:A total of 18 patients(22 eyes)with nAMD were included.The measurements of ACNV,PD,and VLD were 7.247±4.586 and 4.901±3.741 mm^(2),43.202±9.636 and 34.904±10.489,6.339±1.228 and 5.908±1.741 mm^(-1) for SS-OCTA and SD-OCTA,respectively.The differences between the two devices were 2.346±3.030 mm^(2)(Z=-3.782,P<0.0001),8.298±14.160(Z=-2.419,P=0.016),and 0.431±2.114 mm^(-1)(Z=-0.828,P=0.408)for ACNV,PD and VLD,respectively.The ICC between two graders were 0.893(P<0.001),0.902(P<0.001),0.885(P<0.001)for ACNV,PD,VLD in SS-OCTA,and 0.971(P<0.001),0.976(P<0.001),0.973(P<0.001)in SD-OCTA,respectively.CONCLUSION:Both OCTA devices have high imaging reliability.Compared with SD-OCTA,SS-OCTA has a larger ACNV measurements,but doesn’t show better resolution of internal vessels of CNV and well signal strength.

Advances in swept-source optical coherence tomography and optical coherence tomography angiography

Background:The fast development of swept-source optical coherence tomography(SS-OCT)and swept-source optical coherence tomography angiography(SS-OCTA)enables both anterior and posterior imaging of the eye.These techniques have evolved from a research tool to an essential clinical imaging modality.Main text:The longer wavelength and faster speed of SS-OCT and SS-OCTA facilitate better visualization of structure and vasculature below pigmented tissue with a larger field of view of the posterior segment and 360-degree visualization of the anterior segment.In the past 10 years,algorithms dealing with OCT and OCTA data also vastly improved the image quality and enabled the automated quantification of OCT-and OCTA-derived metrics.This technology has enriched our current understanding of healthy and diseased eyes.Even though the high cost of the systems currently limited the widespread use of SS-OCT and SS-OCTA at the first beginning,the gap between research and clinic practice got obviously shortened in the past few years.Conclusions:SS-OCT and SS-OCTA will continue to evolve rapidly,contributing to a paradigm shift toward more widespread adoption of new imaging technology in clinical practice.

Various configuration types of the foveal avascular zone with related factors in normal Chinese adults with or without myopia assessed by swept-source OCT angiography

·AIM:To describe the morphological characteristics of foveal avascular zone(FAZ)in normal Chinese adults with or without myopia by swept-source optical coherence tomography angiography(SS-OCTA)and analyze the possible associated factors.·METHODS:Normal Chinese adults with or without myopia aged between 18 and 60 y were recruited into the study.One eye in each individual was randomly selected for scanning using SS-OCTA.FAZ parameters,central retinal thickness(CRT)and central choroidal thickness(CCT)were then analyzed.Correlations between systemic and ocular variables and FAZ parameters were subsequently evaluated.The subgroup analysis based on refractive error was also carried out.·RESULTS:In total,127 eyes out of 127 normal subjects were finally included in the study(mean age29.5±8.22 y,61 males and 66 females).The pattern of FAZ was variable:round configuration in 28 eyes(22%),quadrilateral configuration in 23 eyes(18%),pentagonal configuration in 20 eyes(16%),oval configuration in 15 eyes(12%),triangular configuration in 6 eyes(5%)and irregular configuration in 35 eyes(28%).The mean area of FAZ was0.37±0.12 mm^(2).Females had a larger FAZ(0.41±0.11 mm^(2)vs0.32±0.11 mm^(2))compared with that of males(P<0.01).All myopic individuals showed smaller FAZ area and perimeter compared with that of normal individuals(P<0.01).There was no obvious correlation between age and FAZ.In the univariate regression analysis,both axial length(AL)and refractive error were significantly related to FAZ parameters.However,only CRT showed negative correlation with FAZ in the multivariate regression analysis.·CONCLUSION:The pattern of FAZ configuration in normal Chinese adults with or without myopia is highly variable.Establishing quantitative parameters of FAZ would not only provide details of macular pathophysiology but could possibly contribute as a biomarker in disease staging.

Comparison of 24×20 mm^(2) swept-source OCTA and fluorescein angiography for the evaluation of lesions in diabetic retinopathy

AIM: To compare ultra-widefield(24×20 mm^(2)) sweptsource optical coherence tomography angiography(SSOCTA) and fluorescein angiography(FA) in the evaluation of diabetic retinopathy(DR) lesions. METHODS: Forty-six eyes of 23 patients with treatmentna?ve DR were included at Peking University People’s Hospital from September 1, 2021, until December 31, 2021, as well as 23 age and gender matched healthy controls. Quantitative assessments of DR lesions on FA and SS-OCTA(superficial capillary plexus, SCP, 24×20 mm^(2)) were performed.RESULTS: Area of fovea avascular zone(FAZ) was larger in DR cases than controls(0.34±0.069 mm^(2) vs 0.287±0.108 mm^(2), P=0.006). In DR eyes, the mean FAZ area was 0.34±0.069 and 0.334±0.087 mm^(2) on SS-OCTA and FA, respectively(P=0.428), while the median FAZ perimeter was 2.382(IQR, 2.201-2.59) and 2.333(IQR, 2.138-2.6) mm on SS-OCTA and FA images(P=0.733). There was no significant difference in the size of the non-perfusion area(NPA) between the images on SS-OCTA and FA(12.389, IQR 4.96-28.3 and 11.125, IQR 5-28.31 mm^(2), P=0.197). The median total microaneurysm(MA) count was 35(IQR, 19-46) and 73(IQR, 43-93) on SS-OCTA and FA(P<0.001), respectively. No significant difference in intra-retinal microvascular abnormality(IRMA) and neovascularization (NV) count was found between the two techniques. The intraclass coefficient(ICCs) of all the parameters above indicated stable repeatability.CONCLUSION: Ultra-widefield SS-OCTA represents a reliable, noninvasive, and quantitative imaging technique in the assessment of microvasculature in DR, which offers a potential substitute for FA in DR evaluation.

超广角光学相干断层扫描血管成像在视网膜静脉阻塞诊断中的应用

目的探讨超广角光学相干断层扫描血管成像(OCTA)在视网膜静脉阻塞(RVO)患者诊断中的价值。方法选取2023年1月至2024年1月在西安爱尔古城眼科医院接受检查并确诊的RVO患者78例(78眼)进行回顾性研究,其中男43例、女35例,年龄(58.7±9.4)岁。所有患者均于2周内分别接受超广角OCTA、荧光素眼底血管造影(FFA)检查,以FFA检查结果作为临床诊断金标准,计算超广角OCTA对视网膜无灌注区的诊断价值。采用配对t检验分析受检者患侧与健侧超广角OCTA检查的视盘区血流密度特征参数差异;采用方差分析法分析FFA与超广角OCTA检查无灌注区面积的差异。结果超广角OCTA检查视网膜层、浅层血管复合体、深层血管复合体无灌注区面积与FFA检出的无灌注区面积比较,差异均无统计学意义(均P>0.05)。视网膜中央静脉阻塞患者患侧视盘区整个图像血管、视盘周血管、整个图像毛细血管、视盘周毛细血管、下方鼻侧、下方颞侧、颞下、颞上、上方颞侧、下方颞侧血流密度均低于健侧[(50.61±4.82)%比(55.17±5.20)%、(51.40±4.77)%比(57.37±5.00)%、(45.68±5.20)%比(48.93±4.88)%、(45.48±5.50)%比(50.30±6.23)%、(43.83±5.50)%比(48.29±7.23)%、(50.90±7.27)%比(57.34±7.86)%、(48.65±6.61)%比(53.43±6.93)%、(49.50±6.14)%比(54.63±7.22)%、(49.33±7.10)%比(55.38±7.50)%、(45.52±6.14)%比(49.58±6.85)%],差异均有统计学意义(均P<0.05)。视网膜分支静脉阻塞患者患侧视盘区整个图像血管、视盘周血管、整个图像毛细血管、视盘周毛细血管、下方鼻侧、下方颞侧、颞下、颞上、上方颞侧、下方颞侧血流密度均低于健侧[(52.33±5.14)%比(55.43±4.88)%、(52.30±5.15)%比(57.43±4.86)%、(46.77±4.98)%比(49.54±5.50)%、(46.13±6.62)%比(50.63±5.87)%、(44.18±5.87)%比(48.43±6.61)%、(51.39±6.98)%比(57.92±6.94)%、(49.66±6.21)%比(53.56±6.60)%、(49.50±6.33)%比(54.81±6.87)%、(49.89±7.09)%比(56.12±7.28)%、(45.83±5.81)%比(50.75±6.43)%],差异均有统计学意义(均P<0.05)。超广角OCTA检查诊断视网膜中央静脉阻塞及视网膜分支静脉阻塞患者无灌注区的灵敏度分别为100.0%(35/35)、81.4%(35/43),特异度分别为86.0%(37/43)、100.0%(35/35)。结论超广角OCTA可检查RVO患眼视盘区血流密度特征,对RVO无灌注的诊断价值较高,且与FFA相比具有无创优势。

超广域SS-OCTA联合超广角激光扫描眼底成像对糖尿病视网膜病变的诊断价值

目的 超广域扫频源光学相干断层扫描血管成像(UWF SS-OCTA)联合超广角激光扫描眼底成像(UWF SLO)对糖尿病视网膜病变(DR)患者病变的检出率以及对DR分级诊断价值的研究。方法 横断面研究。招募在四川省人民医院眼科就诊的糖尿病患者。所有参与者都接受了UWF SS-OCTA、UWF SLO和荧光素眼底血管造影(FFA)检查,用于检测DR病变,包括微动脉瘤(MA)、视网膜内出血(IRH)、视网膜无灌注区(NPAs)、视网膜内微血管异常(IRMAs)、视网膜静脉串珠(VB)、视网膜新生血管(NVE)、视盘新生血管(NVD)及玻璃体积血(VH)。联合三类影像检查(以下简称三联影像)结果作为标准对照,对比不同影像两两联合对DR病变的检出率及对DR严重度分级的一致性。结果 共纳入101例175眼。与三联影像结果相比,UWF SS-OCTA联合UWF SLO对MA、IRH、NPAs、IRMAs、NVE、NVD及VH的检出率分别为91%、83%、77%、69%、27%、10%及12%,Kappa依次为0.812、1.000、1.000、1.000、0.986、0.970及1.000。与三联影像结果相比,UWF SS-OCTA联合UWF SLO对DR的严重度分级具有优异一致性(Kappa=0.943)。结论 UWF SS-OCTA联合UWF SLO能准确识别MA、IRH、NPAs、IRMAs、NVE、NVD及VH,对DR筛查及分级诊断准确性高,适用于临床上对DR的大规模筛查与管理。

厚脉络膜新生血管病变与中心性浆液性脉络膜视网膜病变患者对侧眼脉络膜参数比较研究

目的应用超广角扫频源光学相干断层扫描血管成像(UWF SS-OCTA)比较厚脉络膜新生血管病变(PNV)和中心性浆液性脉络膜视网膜病变(CSC)患者无症状对侧眼的脉络膜参数及形态学变化。方法前瞻性横断面观察研究,纳入2023年4月至2023年9月我院眼科23例CSC患者无症状对侧眼23眼和19例PNV患者无症状对侧眼19眼,以及年龄与性别匹配的22例健康人22眼作为研究对象,分别设为CSC对侧眼组、PNV对侧眼组及健康眼组。三组受试者年龄、男性比例及最佳矫正视力比较,差异均无统计学意义(均为P>0.05),具有可比性。所有研究对象均行UWF SS-OCTA成像检查及比较,记录颞上、上方、鼻上、颞侧、中心凹、鼻侧、颞下、下方、鼻下共9个分区的脉络膜厚度(CT)、脉络膜中大血管层血管密度(血流像素面积与目标区域总面积的比值)、脉络膜血管指数(CVI)(脉络膜血管管腔体积与脉络膜血管及基质总体积的比值)。同时检查并比较各组患者黄斑中心凹下视网膜厚度、黄斑中心凹下脉络膜厚度(SFCT)及涡静脉不对称扩张及吻合情况。结果三组人员SFCT比较,差异有统计学意义(P<0.01)。三组受试者涡静脉不对称扩张或吻合眼数比例比较,差异有统计学意义(P<0.001)。CSC对侧眼组鼻上及鼻侧分区CVI均大于PNV对侧眼组,差异均有统计学意义(均为P<0.05);CSC对侧眼组鼻上、颞侧、中心凹、下方、鼻下分区CVI及平均CVI均大于健康眼组,差异均有统计学意义(均为P<0.05);PNV对侧眼组颞侧、中心凹及下方分区CVI均大于健康眼组,差异均有统计学意义(均为P<0.05)。CSC对侧眼组在颞上、上方、鼻上、中心凹、颞下、平均脉络膜中大血管层血管密度均小于健康眼组,差异均有统计学意义(均为P<0.05);PNV对侧眼组各分区脉络膜中大血管层血管密度均小于健康眼组,差异均有统计学意义(均为P<0.001)。CSC对侧眼组颞上及鼻上分区CT均大于PNV对侧眼组,差异均有统计学意义(均为P<0.05);CSC对侧眼组颞上、上方、鼻上、颞侧、中心凹、下方及鼻下分区CT均大于健康眼组,差异均有统计学意义(均为P<0.05);PNV对侧眼组上方、颞侧、中心凹及下方分区CT均大于健康眼组,差异均有统计学意义(均为P<0.05)。结论本研究从对侧眼角度侧面提供了CSC和PNV可能不是同一疾病不同阶段的验证。CSC与PNV并非单眼疾病,而是单眼表现的双眼脉络膜疾病。

糖尿病性视网膜病变影像学诊断的研究进展

糖尿病性视网膜病变(diabetic retinopathy,DR)是糖尿病的微血管并发症之一,也是使人失明的主要原因之一,对其早期诊断具有重要的临床意义。传统的眼底彩照和眼底荧光血管成像术是DR诊断的金标准方法。近年来新出现的超广角眼底彩照、超广角眼底荧光血管成像术能较传统的眼底彩照和眼底荧光血管成像术更易发现DR周边的视网膜损害,而应用光学相干断层扫描术、光学相干断层扫描血管成像术则有助于眼底微动脉瘤、视网膜新生血管、糖尿病性黄斑水肿等病变的诊断、评估和随访。多种影像学检查手段相结合有助于DR病变的范围、严重程度的定量评估。

Wide‑field swept‑source OCT angiography of the periarterial capillary‑free zone before and after anti‑VEGF therapy for branch retinal vein occlusion

Background:The aim of the study was to investigate the changes in the periarterial capillary-free zone(paCFZ)after anti-vascular endothelial growth factor(VEGF)therapy in patients with branch retinal vein occlusion(BRVO)by widefield swept-source optical coherence tomography angiography(SS-OCTA)and assess their associations with clinical outcomes.Methods:In this retrospective observational study of 54 treatment-naive BRVO patients with macular edema,we reviewed the findings of 12×12 mm^(2)SS-OCTA at baseline,3,6,and 12 months after intravitreal ranibizumab injections.The paCFZ and major retinal artery areas were measured on SS-OCTA images.The paCFZ area to artery area(P/A)ratio was calculated.Results:The paCFZ areas and P/A ratios of first-and second-order arteries were significantly greater in BRVO eyes than in contralateral eyes(all P<0.01),but there were no differences in the first-and second-order artery areas(P=0.20 and 0.25,respectively).The paCFZ areas and P/A ratios decreased significantly at 3,6,and 12 months after anti-VEGF therapy(all P<0.01).The baseline P/A ratio was significantly correlated with the baseline best-corrected visual acuity(BCVA),central retinal thickness,and their improvements at 3,6,and 12 months(all P<0.05).Baseline BCVA and P/A ratios of first-and second-order arteries were independently associated with the final BCVA in multivariate linear regression.Conclusions:Wide-field SS-OCTA shows that anti-VEGF therapy can lead to a significant improvement in the paCFZ parameters in BRVO.Smaller baseline P/A ratios on SS-OCTA tend to predict better visual outcomes at 12 months after anti-VEGF therapy.

中心性浆液性脉络膜视网膜病变涡静脉扩张模式与脉络膜厚度的关系

目的观察中心性浆液性脉络膜视网膜病变(CSC)不同涡静脉扩张模式患眼脉络膜厚度(ChT)变化。方法前瞻性横断面观察性研究。2023年4~10月于解放军中部战区总医院眼科检查确诊的CSC患者80例89只眼(CSC组)纳入研究。其中,男性64例71只眼,女性17例18只眼。选取同期年龄、性别匹配的健康志愿者15名28只眼作为对照组。其中,男性14名26只眼,女性1名2只眼。采用图湃(北京)医疗科技有限公司BM400K BMizar行黄斑区超广角扫频源光相干断层扫描血管成像(OCTA)检查。扫描速率1536 A扫描×1280 B扫描,扫描范围24 mm×20 mm。设备自带软件记录颞上、鼻上、颞侧、中心凹区、鼻侧、颞下、下方、鼻下等9个分区的ChT。横断面(en-face)OCTA模式观察脉络膜中大血管层上下涡静脉解剖和功能吻合情况。依据en-face图像脉络膜中大血管层显示的涡静脉扩张差异,将CSC组患眼再分为上优势型组、对称型组、下优势型组,分别为36、35、18只眼。两组间比较采用连续变量采用独立样本t检验或Mann-Whitney检验,多组间比较采用单因素方差分析或Kruskal-Wallis H检验,分类变量采用χ^(2)检验或Fisher检验。结果与对照组比较,CSC组黄斑中心凹区及不同区域ChT均增厚,其中中心凹差异最大,差异均有统计学意义(t=3.345、5.018、2.902、4.667、7.276、3.307、3.868、4.795、2.583,P<0.05)。与对照组ChT比较,上优势型组颞下区域,差异无统计学意义(t=1.510,P>0.05);其他各区域,差异均有统计学意义(t=3.207、5.163、2.526、4.310、6.285、2.656、3.812、2.173,P<0.05)。对称型组中心凹区及其他各区域,差异均有统计学意义(t=4.488、5.554、3.457、5.314、7.256、3.507、5.584、6.019、2.994,P<0.05)。下优势型组颞上、鼻上区域,差异无统计学意义(t=1.150、1.465,P>0.05);其他各区域,差异均有统计学意义(t=2.278、4.168、5.244、2.783、5.040、3.432、2.095,P<0.05)。结论En-face超广角OCTA上涡静脉扩张分布与ChT呈对应关系,CSC患眼脉络膜引流的首选途径可能是上优势型涡静脉引流系统。