Optical coherence tomography angiography is an efficient tool to assess optic nerve perfusion

BackgroundTo investigate retinal neurovascular structural changes in patients with ischemic stroke (IS) using optical coherence tomography angiography (OCTA).Materials and MethodsThe cross-sectional study was conducted in Guangdong Provincial People’s Hospital, China, consisting of 159 eyes from IS patients and 109 eyes from age-matched control subjects. Retinal microvascular parameters including the vessel density (VD) of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillary (RPC), and neural parameters such as ganglion cell complex thickness (GCCt) and retinal nerve fibre layer thickness (RNFLt) were measured by OCTA.ResultsThe VD of SCP and DCP in the macular area were significantly reduced in IS patients compared to the control group (all p < 0.001). The VD of RPC at the optic disc was also significantly reduced in IS patients (all p < 0.05). IS patients showed reduced GCCt and RNFLt and increased GCC focal loss volume and global loss volume compared with the controls (all p < 0.05). Among patients with IS, the parafovea SCP VD was positively correlated with GCCt (r = 0.346–0.408, all p < 0.001) but not with DCP VD (all p > 0.1). In the optic disc region, the whole image RPC VD was positively correlated with mean RNFLt (r = 0.467–0.548, all p < 0.001).ConclusionReduction of retinal VD, GCCt and RNFLt was observed in patients with IS. The parafovea SCP VD and RPC VD were positively correlated with GCCt and RNFLt, respectively.

Glaucoma patients had a reduction in the inner annulus peripapillary choroidal microvascular density (PCMD) that became worse as the glaucoma severity progressed, which might provide new evidence supporting the vascular theory. To compare PCMD among normal tension glaucoma (NTG), primary open angle glaucoma (POAG), and healthy controls using optical coherence tomography (OCT) angiography (OCTA). The study included 40 POAG, 25 NTG, and 33 healthy controls. All subjects underwent OCT and OCTA testing. The inner annulus and outer annulus PCMD, as well as peripapillary vessel density (VD), were calculated. One-way analysis of variance was used to compare the vascular parameters of the 3 groups. Pearson correlation analysis or Spearman correlation test was used to evaluate the correlation between PCMD and glaucomatous severity factors. The spatial positional relationship between PCMD and corresponding peripapillary retinal nerve fiber layer (RNFL) thickness and visual field (VF) mean deviation (MD) was also assessed. The average and 4 quadrants of the inner annulus PCMD and peripapillary VD in the 2 glaucomatous groups were significantly lower than in normal eyes ( P <0.05). Strong correlations were found between inner annulus PCMD and VF MD, peripapillary VD, and RNFL in POAG patients. Similarly, the inner annulus PCMD in NTG patients was strongly correlated with peripapillary VD and RNFL (all r >0.5). Strong positional correlations were found between inner superior quadrantal PCMD and RNFL thickness in both POAG and NTG patients ( r =0.566 and 0.731, respectively). Likewise, inner inferior quadrantal PCMD exhibited a strong correlation with RNFL thickness in POAG patients ( r =0.608). Strong positional correlations were also found between inner superior PCMD and VF MD in both POAG and NTG patients ( r =0.589 and 0.622, respectively). Inner inferior PCMD exhibited a moderate correlation with VF MD in both POAG and NTG patients ( r =0.487 and 0.440, respectively). The study found that the inner annulus PCMD decreased to varying degrees in NTG and POAG patients. The inner annulus PCMD was closely related to the structural and visual function parameters of glaucoma in both NTG and POAG. Furthermore, inner PCMD demonstrated a spatial correlation with corresponding RNFL thickness and VF MD.

Capillary and neuronal tissue loss occur both globally and with regional specificity in pre-perimetric glaucoma patients at the level of the optic nerve and macula, with perifovea regions affected earlier than parafovea areas. To investigate optic nerve head (ONH) and macular vessel densities (VD) and structural parameters assessed by optical coherence tomography angiography in pre-perimetric open angle glaucoma (ppOAG) patients and healthy controls. In all, 113 healthy and 79 ppOAG patients underwent global and regional (hemispheric/quadrants) assessments of retinal, ONH, and macular vascularity and structure, including ONH parameters, retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness. Comparisons between outcomes in ppOAG and controls were adjusted for age, sex, race, BMI, diabetes, and hypertension, with P <0.05 considered statistically significant. In ppOAG compared with healthy controls: RNFL thicknesses were statistically significantly lower for all hemispheres, quadrants, and sectors ( P <0.001-0.041); whole image peripapillary all and small blood vessels VD were statistically significantly lower for all the quadrants ( P <0.001-0.002), except for the peripapillary small vessels in the temporal quadrant (ppOAG: 49.66 (8.40), healthy: 53.45 (4.04); P =0.843); GCC and inner and full macular thicknesses in the parafoveal and perifoveal regions were significantly lower in all the quadrants ( P =0.000- P =0.033); several macular VD were significantly lower ( P =0.006-0.034), with the exceptions of macular center, parafoveal superior and inferior quadrant, and perifoveal superior quadrant ( P >0.05). In ppOAG patients, VD biomarkers in both the macula and ONH, alongside RNFL, GCC, and macular thickness, were significantly reduced before detectable visual field loss with regional specificity. The most significant VD reduction detected was in the peripheric (perifovea) regions. Macular and ONH decrease in VD may serve as early biomarkers of glaucomatous disease.

To compare the foveal avascular zone (FAZ), macular and peripapillary vessel density and retinal nerve fiber layer (RNFL) thickness between pediatric migraine patients and healthy subjects. A total of 108 eyes of 54 children with migraine without aura and 94 eyes of 47 age- and gender-matched healthy subjects were included. Capillary vessel density (CVD) in superficial (SCP) and deep (DCP) retinal capillary plexus, peripapillary region, FAZ, and RNFL thickness were analyzed by optical coherence tomography-angiography. The mean ages were 12.4 ± 3.3years (range 6-18) in patients with migraine and 12.6 ± 2.9years (range 5-18) in healthy controls (p = 0.742). The mean FAZ area measured 0.27 ± 0.09 mm2 in the pediatric migraineurs and 0.26 ± 0.09 mm2 in healthy controls (p = 0.53). There was no significant difference in any measurement of SCP, DCP, peripapillary CVD, and RNFL thickness between study groups (p > 0.05 for all). The pediatric migraine disability assessment test (PedMIDAS) negatively correlated with some of the CVD and RNFL measurements in pediatric migraine patients (p < 0.05). The macular and peripapillary microvasculature were not significantly different during an attack-free period in pediatric migraine patients than in healthy subjects.

Capacidad diagnóstica de la densidad vascular papilar y macular frente a parámetros estructurales con tomografía de coherencia óptica en el glaucoma seudoexfoliativo

Introduction:Monitoring and diagnosing glaucoma until 2017 included funduscopy, IOP measurements, gonioscopy, pachymetry, as well as visual field tests, optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A). Radial peripapillary capillaries (RPC) can be observed by fluorescein angiography, as well as histologically - superficial and deep capillary layer.Aim:To correlate density of radial peripapillary capillary network (RPC) and retinal nerve fiber layer (RNFL) thickness in eight peripapillary segments in patients with a primary open angle glaucoma (POAG) which have the disease under 10 years of duration, over 10 years of duration and in a group of healthy patients.Methods:This is a cross-sectional review which included three groups of patients: POAG patients under 10 years of disease duration, over 10 years of disease duration and control group of patients. The study is performed on the commercial optical coherence tomography angiography system (AngioVue, Avanti RTVue-XR, Optovue, CA). Sectoral RPC density values, RPC maps and RNFL thickness were analyzed in three groups of patients, data was compared and correlation between parameters was examined.Results:Mean RPC Density values in both superior segments (S1, S2) were significantly lower in patients with glaucoma over 10 years of disease duration compared to patients with glaucoma under 10 years of disease duration (p<0.05). Statistically significant positive correlation was established between RNFL thickness and RPC density in all eight peripapillary segments.Conclusion:Analysis of radial peripapillary capillary network density on optical coherence tomography angiography may provide an earliest functional sign of progressive optic nerve disease and new insights into the pathophysiology of glaucomatous damage.

Introduction: This study aims to investigate the changes of retinal vascular system in primary angle closure glaucoma (PACG) and acute primary angle closure (APAC) by optical coherence tomography (OCT) angiograph (OCTA) and to evaluate the diagnostic ability of changes of vessel density (VD) in different sectors and layers of optic disc and macular area in APAC and PACG. Methods: In this cross-sectional, observational study, 21 APAC patients (22 eyes) and 21 PACG patients (27 eyes) along with 17 healthy people were enrolled from August 2018 to March 2019. Optic disc region and macular region were imaged using swept-source OCTA system. VD of the macular region was quantified by Image J (1.52a, USA) and Matlab 2018a. The circumpapillary retinal nerve fiber layer (cpRNFL) thickness and ganglion cell complex thickness were obtained by spectral-domain OCT. Results: Compared with the healthy group, the cpRNFL thickness in superior sector was thicker in the APAC group, and this area had the most diffuse microvascular dropout as well. The difference in the macular superficial capillary plexus (SCP) VD between APAC and the control group was not statistically significant. The area under the ROC curves (AUC) of the total optic disc VD in the radial peripapillary capillary (RPC) layer was higher than the AUC of the papillary VD in the optic nerve head (ONH) layer. Compared to the control group, the total optic disc VD, peripapillary VD, and each quadrant of peripapillary VD were decreased in PACG (p < 0.01). In PACG macular region, SCP VD, and deep capillary plexus (DCP) VD, parafovea VD (except temporal sectors) decreased (p < 0.01). The PACG eyes had a greater decrease percentage of VD in total ONH than total macula. The diagnostic value of the VD in the ONH layer and the RPC layer was similar. The diagnostic value of the SCP VD in the macula was greater than the DCP VD in the macula. The AUC was no significant difference between cpRNFL thickness and the total optic disc VD AUC. Conclusion: Elevated intraocular pressure preferentially affects vascular perfusion in the optic disc region more than the macular region in APAC and PACG. In the APAC eyes, there was a perfusion defect in the optic disc region and an increase in RNFL thickness. In this study, the OCTA vascular parameters have similar performance to the OCT structural parameters for glaucoma diagnosis in PACG.

The aim of this study was to investigate the changes in vessel density (VD) in glaucoma patients and to investigate the relationship between VD and structural parameters using optical coherence tomography angiography. Our study included 25 primary open-angle glaucoma (POAG) patients, 25 pseudoexfoliation glaucoma (PXG) patients and 25 healthy individuals. All patients underwent 6 × 6mm retinal angiography (upper limit: internal limitan membrane [ILM], lower limit: 10µm inferior to inner plexiform layer) and 4.5 × 4.5mm disk angiography (upper limit: ILM, lower limit: posterior border of the retinal nerve fiber layer [RNFL]) via an optical coherence tomography (OCT) system (AngioVue, Optovue). Measures of vascular density were as follows: total area VD (tVD), intrapapillary VD (iVD), peripapillary VD (pVD) and parafoveal VD (pfVD). In addition to performing comparisons, the correlations between pVD, retinal nerve fiber layer (RNFL) thickness and optic nerve head measurement results were investigated. A total of 75 individuals were included in our study. In the POAG and PXG groups, tVD and pVD values were significantly lower than the control group (median tVDs were: 45.4, 45.9, 50.0, and median pVDs were: 50.0, 50.3, 53.1, respectively) (confidence intervals were: -9.8/-1.1 for pVD and -8.6/-1.4 for tVD). Significantly lower pf-VD values were detected in the PXG group compared to the control group (p < 0.05). There were strong positive correlations between RNFL thickness and pVD in in glaucoma groups (p < 0.001). There was no correlation between pVD and disk area, intraocular pressure and age in glaucoma patients. Patients using beta-blockers had significantly lower tVD and pVD values compared to those who did not (p < 0.05). The low VD values in glaucomatous eyes and the strong correlations between that values and RNFL thickness demonstrate a relationship between structural parameters and vascular parameters.

Objective To measure RNFL thickness by Frequency-domain optical coherence tomography (OCT) in patients with different stages of primary glaucoma (CACG and POAG),to evaluate the correlation between RNFL thickness and visual field mean defect (MD),to detect RNFL thickness change of early stage primary glaucoma,and to discuss the clinical significance in the early diagnosis of primary glaucoma objectively. Methods Ninety-two subjects of 40 normal and 52 with different stages of primary glaucoma were enrolled in this study.RNFL thickness was measured by Zeiss Cirru HD-OCT,and visual field was tested by Zeiss Humphrey-750.The association between visual field MD and RNFL thickness was evaluated with Pearson correlation coefficients. Results In the normal group,mean RNFL thickness was 112.91±9.36μm; the early period glaucoma group 94.43±7.67μm; the middle period glaucoma group 80.82±10.36μm; the later period glaucoma group 67.86±8.01μm.Visual field MD in each group was-0.88±1.53dB,-4.26±1.83dB,-7.43±2.64dB and -17.06±5.85dB.The differences in mean RNFL thickness and visual field MD between normal and each stage glaucoma group were significant (P ＜0.05) by independent sample t-test.In each stages of glaucoma group,mean RNFL thickness and visual field MD (early period:r =-0.537,middle period:r =-0.615,later period:r=-0.804) correlated significantly (P ＜0.05).In the early period glaucoma group,superior RNFL thickness was 116.32±11.65μm,inferior RNFL thickness 105.58±9.73μm,nasal RNFL thickness 75.40±10.91μm,and temporal RNFL thickness 70.28±13.08μm.In group B,superior RNFL thickness was 140.15±8.79μm,inferior RNFL thickness 137.29±10.07μm,nasal RNFL thickness 90.20±14.19μm,and temporal RNFL thickness 88.43±10.85μm.The difference of superior and inferior RNFL thickness between group A1 and group B had statistical significance tested by independent sample t-test,P ＜0.05; nasal and temporal RNFL thickness between group A1 and group B was tested by independent sample t-test,P ＞0.05,there was no statistical significance difference. Conclusions Frequency-domain OCT detected that the average of RNFL thickness become thinning with the progression of disease in the primary glaucoma patients,have negative correlation with vision MD,it is able to objectively reflect the degree of glaucomatous optic nerve damage.Frequency-domain OCT can show significantly decreased superior and inferior RNFL thickness of the early period primary glaucoma,which shows good ability in distinguishing normal from early period primary glaucomatous eyes. Key words: Optical coherence tomography (OCT); Retinal nerve fiber layer (RNFL); Mean defect (MD); Early diagnosis primary glaucoma

New Findings in Early-Stage Keratoconus: Lamina Cribrosa Curvature, Retinal Nerve Fiber Layer Thickness, and Vascular Perfusion

To evaluate the structural, microvascular, and functional progression of normal tension glaucoma (NTG) with or without high myopia by examining longitudinal changes in optical coherence tomography angiography (OCTA) and visual field (VF) parameters. We evaluated 61 NTG eyes and classified 25 of the eyes with axial lengths (ALs) of ≥26 mm as highly myopic. We assessed the rate of change in OCTA parameters, namely radial peripapillary capillary (RPC) vessel density (VD), parafovea VD, deep parafovea VD, retinal nerve fibre layer (RNFL) thickness, and ganglion cell complex thickness. We evaluated the correlation of the rate of change in OCTA parameters with VF loss and AL. Among the 61 NTG eyes, rates of loss of RPC VD, parafovea VD, deep parafovea VD, and RNFL thickness were significantly different from zero despite the nonsignificant rate of change in VF mean deviation (MD). Changes in these OCTA parameters did not differ significantly in highly myopic NTG eyes. The rate of change in VF MD was significantly correlated with the rate of change in parafovea VD in highly myopic and non-highly myopic NTG eyes. In highly myopic NTG eyes, AL was negatively correlated with the rates of loss of RNFL thickness, VF MD, and VF PSD. NTG eyes with a relatively stable VF exhibited loss of VD and RNFL thickness. VF progression in NTG was correlated with decreasing parafovea VD, indicating a structure-function correlation. Greater AL may indicate faster VF loss and RNFL thinning in highly myopic NTG eyes.

: Aim of this study was to establish a correlation between findings obtained from Optical Coherence Tomography Angiography (OCT-A) and Retinal Nerve Fiber Layer (RNFL) thickness measurements in a series of moderate Primary Open Angle Glaucoma (POAG) cases and normal controls. In this observational cross-sectional study a total of 100 eyes were included, comprising 50 eyes with glaucoma and 50 control eyes without glaucoma. All participants underwent comprehensive anterior and posterior segment evaluations, intraocular pressure (IOP) measurement using Goldmann applanation tonometer, gonioscopy, visual field testing, and OCT imaging, which included OCT-A. The OCT-A imaging was performed using the RTvue XR Avanti by Optovue. Two types of analysis were conducted: a comparative analysis between the normal and glaucomatous groups using an unpaired t-test to assess differences in RNFL thickness and vessel density values, and a correlation analysis within each group to examine the strength of correlation between RNFL loss and reduction in vascular density. The results showed a significant reduction in vessel density index in all quadrants of glaucomatous eyes compared to normal eyes. Moreover, this reduced vessel density was found to be significantly correlated with the reduction in RNFL thickness in glaucoma patients. Specifically, the uperior and inferior quadrants exhibited the strongest correlation with each other. The severity of vascular compromise demonstrated a significant correlation with the extent of retinal nerve fiber loss in patients with glaucoma. OCT-A can serve as a valuable adjunct in the diagnosis of glaucoma and monitoring its progression.

BackgroundQuantitative assessment of optic nerve damage is important in the evaluation of optic neuritis (ON) and multiple sclerosis (MS).ObjectiveTo detect optic nerve damage using optical coherence tomography (OCT) and OCT...

PV058 / #431Poster Topic:AS06 - ComorbiditiesBackground/PurposeRetinopathy is a common ocular manifestation in SLE, and it is often caused by microangiopathy resulting from immune complex deposition, leading to vasculitis and thrombosis in the retinal microcirculation. Antiphospholipid antibodies (aPL) are present in around 30% of SLE patients, with 10% developing antiphospholipid syndrome (APS). Retinal involvement in APS can manifest as arterial and venous thrombosis. While macrovascular involvement manifests with prominent symptoms such as amaurosis fugax or transient diplopia, microvascular involvement may remain asymptomatic and manifest at the retinal level with microhaemorrhages, microaneurysms, and cotton-wool spots. This study aimed to evaluate the association between aPL positivity and preclinical retinal vascular changes in SLE patients.MethodsThis cross-sectional, two-center study included 112 SLE patients and 134 healthy controls recruited from Hospital Clinic de Barcelona and Policlinico Tor Vergata in Rome. Patients underwent ophthalmological evaluations, including visual acuity measurement, slit-lamp biomicroscopy, intraocular pressure measurement, and fundus examination. Retinal structural changes, such as macular thickness (MT) and retinal nerve fiber layer (RNFL) thickness, were assessed using spectral-domain optical coherence tomography (SD-OCT). Retinal vascular changes, including vessel density (VD), vascular perfusion (VP), and foveal avascular zone (FAZ), were evaluated using OCT angiography (OCTA). Statistical analysis was performed to compare differences between SLE subgroups stratified based on aPL positivity or the presence of APS.This cross-sectional, two-center study included 112 SLE patients and 134 healthy controls recruited from Hospital Clinic de Barcelona and Policlinico Tor Vergata in Rome. Patients underwent ophthalmological evaluations, including visual acuity measurement, slit-lamp biomicroscopy, intraocular pressure measurement, and fundus examination. Retinal structural changes, such as macular thickness (MT) and retinal nerve fiber layer (RNFL) thickness, were assessed using spectral-domain optical coherence tomography (SD-OCT). Retinal vascular changes, including vessel density (VD), vascular perfusion (VP), and foveal avascular zone (FAZ), were evaluated using OCT angiography (OCTA). Statistical analysis was performed to compare differences between SLE subgroups stratified based on aPL positivity or the presence of APS.ResultsOCTA analysis revealed decreased vascular parameters in SLE patients compared to controls in both cohorts. Specifically, the Barcelona cohort showed significant reductions in VD and VP (Table 1), while the Rome cohort showed significant reductions in parafoveal superficial VD. No clear association was found between aPL positivity and alterations in OCTA vascular parameters in SLE patients. However, a possible correlation between aPL positivity and variations in RNFL thickness was observed in both cohorts (Table 2 and Table 3).Table 1.Spectral-domain Optical Coherence Tomography (SD-OCT) and Angiography by Optical Coherence Tomography (OCTA) parameters at Barcelona cohort, right eyea.Table 2.Spectral-domain Optical Coherence Tomography (SD-OCT) and Angiography by Optical Coherence Tomography (OCTA) parameters at Barcelona cohort, by antiphospholipid antibodies, right eyea.Table 3.Spectral-domain Optical Coherence Tomography (SD-OCT) and Angiography by Optical Coherence Tomography (OCTA} parameters at Rome cohort, by antiphospholipid antibodies, right eyea.ConclusionsWhile SLE patients exhibited significant alterations in vascular OCTA parameters compared to healthy controls, the study did not find a definitive association between aPL positivity and changes in OCTA parameters in SLE patients. However, the study suggests a potential correlation between aPL positivity and variations in RNFL thickness in both cohorts. Further studies are needed to confirm these results and understand their biological significance.

BackgroundTo evaluate postoperative changes in retinal capillary plexus and to assess contributing factors in postoperative visual improvement using optical coherence tomography angiography (OCT-A) in patients with idiopathic epiretinal membrane (iERM) post membrane removal.MethodsPatients scheduled for vitrectomy and membrane peel for iERM were enrolled. 35 subjects were included for this study. OCT-A was used to measure the FAZ related parameters and the superficial and deep capillary plexus layers using 3 mm × 3 mm scans. Measurements were taken before surgery and at every post-surgical follow-up. The unaffected fellow eyes were used as controls. Evaluated factors included: BCVA, vessel density (VD) and retinal thickness (RT) in five regions, FAZ area, FAZ perimeter (PERIM), acircularity index (AI) and foveal vessel density (FD).ResultsCompared with the control group, the foveal vessel density (FVD) in superficial capillary plexus (SCP) was greater in the epi-retinal membrane group (P < 0.0001), whereas both groups had comparable parafoveal vessel density (PRVD) in SCP (p > 0.05). After surgery there was a reduction in the PRVD in SCP. The FVD in DCP increased and the PRVD in DCP decreased at baseline (p < 0.001). After surgery there was an increase in PRVD in DCP. By 6 months post-op, the PRVD had no statistically significant difference compared with the control group (p > 0.05). D-value of LogMAR BCVA was positively correlated with pre-op LogMAR BCVA (p < 0.0001), FVD in SCP (p < 0.001). It was negatively correlated with FAZ area (P < 0.001) and PERIM (P < 0.05).ConclusionsVitrectomy and membrane removal led to the decrease of VD in SCP and the increase of PRVD in DCP. Patients with a more severe iERM may receive greater visual improvement with surgery.Trial registrationTrial registration number (TRN) and date of registration.ChiCTR2000031289, retrospectively registered, 2020.03.26.