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Microvasculature Changes of Myopic Choroidal Neovascularization and the Predictive Value of Feeder Vessel Disappearance after Ranibizumab Treatment Revealed Using Optical Coherence Tomography Angiography
摘要： Aim: To investigate vascular changes of myopic choroidal neovascularization (mCNV) after ranibizumab treatment using optical coherence tomography-angiography (OCTA). Methods: Consecutive subjects with a diagnosis of mCNV were included. Patients underwent intravitreal injection of ranibizumab treatment with a 6-month follow-up. All patients underwent a complete ophthalmological examination and OCTA evaluation. The 3 × 3 OCTA en face images were analyzed for the absence/presence of mCNV, CNV area, and CNV network morphology. In particular, the morphology of the mCNV was analyzed in order to detect the presence/absence of feeder vessels. Results: Eleven subjects were evaluated. At baseline, the mCNV was identified in all cases on OCTA. At 6 months, the mean mCNV area was not statically significantly reduced in comparison with baseline values (p > 0.05), while the morphologic analysis revealed a complete disappearance of the feeder vessel in 6 eyes. The subgroup analysis of these latter showed that the CNV area was significantly reduced, visual acuity had improved, and only one intravitreal injection was administrated over the entire follow-up period. Conclusions: OCTA allowed the detection of qualitative and quantitative vascular changes in mCNV. The disappearance of the feeder vessel was associated with better anatomical as well as functional outcomes at the last follow-up visit.
关键词： Myopic choroidal neovascularization,Pathologic myopia,Optical coherence tomography angiography
更新于2025-09-12 10:27:22
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Analysis of Choroidal Thickness and Vascular Density Using Optical Coherence Tomography Angiography after Laser Photocoagulation
摘要： Purpose: To evaluate the changes in choroidal thickness and superficial vascular density of the macula and optic disc using optical coherence tomography angiography after laser photocoagulation. Methods: We conducted a retrospective chart review of 25 eyes of diabetic retinopathy patients who underwent panretinal photocoagulation. The macula and optic disc were divided into nine areas, and the vascular density of each area was quantitatively measured using optical coherence tomography angiography. The changes in vascular density and choroidal thickness were analyzed before laser photocoagulation and at 1 week after, 1 month after, and 3 months after treatment. Results: In the panretinal photocoagulation group, the average vascular densities of the macula were 13.5 ± 3.6 mm-1 before treatment, and 14.7 ± 3.1 mm-1 after 1 week, 13.7 ± 2.6 mm-1 after 1 month, and 12.8 ± 3.8 mm-1 after 3 months of treatment. The average vascular densities of the optic disc were 14.7 ± 5.2 mm-1 before treatment, and 14.1 ± 4.7 mm-1 after 1 week, 14.8 ± 5.3 mm-1 after 1 month, and 15.0 ± 4.7 mm-1 after 3 months of treatment. The average subfoveal choroidal thicknesses were 327.5 ± 57.9 μm before treatment, and 334.4 ± 52.5 μm after 1 week, 291.2 ± 52.9 μm after 1 month, and 286.3 ± 44.4 μm after 3 months of treatment. Conclusions: The vascular density of the macula increased temporarily after 1 week of treatment but decreased afterwards. The vascular density of the optic disc decreased after 1 week of laser treatment but increased over time. The subfoveal choroidal thickness increased after 1 week of laser treatment but decreased afterwards.
关键词： Vascular density,Panretinal photocoagulation,Optical coherence tomography angiography
更新于2025-09-11 14:15:04
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Assessing the Use of Incorrectly Scaled Optical Coherence Tomography Angiography Images in Peer-Reviewed Studies
摘要： IMPORTANCE Individual differences in axial length affect the lateral magnification of in vivo retinal images and as a result can affect the accuracy of quantitative measurements made from these images. As measurements from optical coherence tomography angiography (OCTA) images are becoming increasingly used in the diagnosis and monitoring of a wide range of diseases, evaluating which studies use correctly scaled images is crucial to their interpretation. OBJECTIVE To perform a systematic literature review to assess the percentage of articles that report correcting the scale of their OCTA images for individual differences in retinal magnification. EVIDENCE REVIEW A PubMed (MEDLINE) search was conducted for articles on OCTA retinal imaging published between June 1, 2015, and June 1, 2018. Initial results included 7552 articles. Initial exclusion criteria removed studies of animal models, as well as reviews, letters, replies, comments, and image-based or photographic essays. Articles not written in English and those that required purchase from non–English language websites were excluded. Articles that did not use OCTA for imaging the retina were also excluded. Remaining articles were reviewed in detail to assess whether the OCTA measurements required correct lateral scaling, and if so, whether axial length was reported or used to scale the images. We also determined the number of articles that mentioned the lack of correct lateral scaling as a limitation of the study. FINDINGS A total of 989 articles were included in the detailed review. Of these, 509 were determined to require correct image scaling for their analyses, but only 41 (8.0%) report measuring and using axial length to correct the lateral scale of their OCTA images. Furthermore, of the 468 articles that did not correctly scale their images, only 18 (3.8%) mentioned this as a limitation to their study. CONCLUSIONS AND RELEVANCE These findings suggest that most peer-reviewed articles in PubMed that use quantitative OCTA measurements use incorrectly scaled images. This could call into question the conclusions of such studies and warrants consideration by OCTA manufacturers, physicians, authors, journal reviewers, and journal editors.
关键词： retinal imaging,axial length,optical coherence tomography angiography,lateral scaling,OCTA
更新于2025-09-11 14:15:04
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Macular microvasculature features before and after vitrectomy in idiopathic macular epiretinal membrane: an OCT angiography analysis
摘要： Purpose To evaluate pre-operative and post-operative morphologic characteristics in idiopathic macular epiretinal membrane (ERM) by optical coherence tomography angiography (OCTA). Methods Thirty-three subjects with unilateral idiopathic ERM were enrolled and the contralateral eyes served as controls. Vascular parameters including super?cial capillary plexus (SCP), deep capillary plexus (DCP), outer capillary plexus (OCP), and choroidal capillary plexus (CCP) were evaluated by OCTA. Results The super?cial foveal avascular zone (FAZ) was signi?cantly smaller in eyes with ERM (P < 0.0001). The vessel densities (VDs) were signi?cantly increased in the fovea but dramatically decreased in the parafovea in SCP and DCP of ERM eyes (all P < 0.0001), in contrast to those in OCP and CCP. The blood ?ow was augmented in OCP but declined in choroid compared with the controls. In CCP, the mean foveal VD in ERM was signi?cantly smaller (P = 0.023), whereas parafoveal VD did not signi?cantly change (P = 0.66). At 6 months after surgery, ?ow area was decreased in OCP (P = 0.0007), and foveal and parafoveal VDs were signi?cantly altered in all layers except the foveal VD in OCP and the choroid (all P < 0.05). The total and inner retinal thickness of the fovea and parafovea were correlated with pre-operative and post-operative visual outcomes, respectively. Smaller FAZ and greater interocular differences between post-operative and fellow eyes in FAZ were associated with worse post-operative visual outcomes. Conclusions OCTA provides a better display of the vascular network of the retina and choroid to evaluate the severity and surgical prognosis of ERM patients.
关键词： Microvasculature,Vitrectomy,Epiretinal membrane,Optical coherence tomography angiography
更新于2025-09-10 09:29:36
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Changes in retinal flow density measured by optical coherence tomography angiography in patients with carotid artery stenosis after carotid endarterectomy
摘要： The aim of the study presented here was to evaluate retinal and optic nerve head (ONH) perfusion in patients with severe asymptomatic carotid artery stenosis (CAS) compared with healthy controls and to analyze the impact of carotid endarterectomy using optical coherence tomography angiography (OCT-A). 25 eyes of 25 patients with CAS (study group) and 25 eyes of 25 healthy controls (control group) were prospectively included in this study. OCT-A was performed using RTVue XR Avanti (Optovue, Inc, Fremont, California, USA). The flow density data in the superficial and deep retinal OCT-angiogram of the macula and in the radial peripapillary capillary network (RPC) of the ONH were extracted and analyzed. The flow density in the superficial retinal OCT angiogram of the macula and in the ONH were significantly lower in the study group compared with the control group (macula: p = 0.003) (ONH: p = 0.013). The flow density in the ONH improved significantly after carotid endarterectomy (p = 0.004). A reduced flow density was observed in patients with CAS when compared with healthy controls. The flow density also improved after carotid endarterectomy. Quantitative changes in the microvascular density, as measured using OCT-A, could well be useful in the diagnosis of CAS and the evaluation of therapy success.
关键词： carotid endarterectomy,optical coherence tomography angiography,carotid artery stenosis,retinal flow density
更新于2025-09-10 09:29:36
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Morphometrical evaluation of the choriocapillaris imaged by swept-source optical coherence tomography angiography
摘要： Purpose: To assess the reproducibility of quantitative morphometrical evaluation of the choriocapillaris imaged with swept-source optical coherence tomography angiography (SS-OCTA). Subjects and methods: This observational, cross-sectional case series included 35 eyes of healthy individuals and 32 eyes of 32 patients. Two images of the fovea were taken using SS-OCTA with 3×3 mm squares. Images of the choriocapillaris within 800×800 pixel squares centered at the fovea were analyzed morphometrically using open-source software “AngioTool” that applies a Gaussian recursive filter and multiscale Hessian enhancement. This program’s vessel thickness and intensity parameters can be changed to aid vessel detection. We measured the pairs of images per eye with different parameter sets and calculated the intraclass correlation (ICC) for the morphometrical results. After determining the parameters that produced high reproducibility, we evaluated regional variations in 800×800 pixel mm squares within the fovea. Results: The ICCs for vessel area, total vessel length, vessel diameter index, and mean lacunarity were over 0.9 using the parameters of “vessel thickness” 3–4 and intensity 15 in the group including all subjects. When measurements were performed using these same parameter values, the vessel density and mean vessel diameter index were 60.5% and 19.1±0.389, respectively. Vessel density, vessel length, vessel diameter index, and mean lacunarity did not change significantly within an 800×800 pixel square centered at the fovea except for the 200×200 pixel square at the foveal center. Conclusion: SS-OCTA images of the choriocapillaris can be measured with high reproducibility by morphometrical evaluation using open-source software with multiscale Hessian enhancement. Such automated morphometric analysis can provide an objective evaluation of the choriocapillaris.
关键词： choriocapillaris,swept-source optical coherence tomography angiography,morphometry,vessel density
更新于2025-09-10 09:29:36
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Optical coherence tomography angiography (OCTA) flow speed mapping technology for retinal diseases
摘要： Introduction: Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality for depth-resolved visualization of retinal vasculature. Angiographic data couples with structural data to generate a cube scan, from which en-face images of vasculature can be obtained at various axial positions. OCTA has expanded understanding of retinal vascular disorders and has primarily been used for qualitative analysis. Areas covered: Recent studies have explored the quantitative properties of OCTA, which would allow for objective assessment and follow-up of retinal pathologies. Various quantitative metrics have been developed, such as foveal avascular zone area and vessel density. However, quantitative assessment of the characteristics of retinal blood flow remains limited, as OCTA provides an image depicting either the presence or absence of flow at a particular region without information of relative velocities. The development of variable interscan time analysis (VISTA) overcomes this limitation. The VISTA algorithm generates a color-coded map of relative blood flow speeds. VISTA has already demonstrated utility in furthering our understanding of various retinal pathologies, such as geographic atrophy, choroidal neovascularization, aneurysmal type 1 neovascularization, and diabetic retinopathy. Expert commentary: VISTA, an OCTA flow speed mapping technique, may have a role in developing the utility of OCTA as a screening tool.
关键词： flow speed mapping,diabetic retinopathy,age-related macular degeneration,VISTA,quantitative OCTA,OCTA,Optical coherence tomography angiography,variable interscan time analysis,OCT
更新于2025-09-10 09:29:36
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Optical coherence tomography angiography in exudative age-related macular degeneration: a predictive model for treatment decisions
摘要： Aims To evaluate on optical coherence tomography angiography (OCT-A), the predictive role of different qualitative findings of choroidal neovascularisations (CNV) in assessing the status of exudative age-related macular degeneration (eAMD) and to develop a potential model to predict the CNV activity. Methods Retrospective review of the multimodal imaging records of patients with eAMD obtained during treatment for type 1 or type 2 CNV. The qualitative analysis of CNVs on OCT angiograms assessed the presence or absence of tiny branching vessels, loops, peripheral anastomotic arcades and choriocapillaris hypointense halo. These findings were then correlated with those of structural OCT scans. A score forecast was built and validated. results One hundred and twenty-six eAMD eyes were enrolled in the study. Exudation was observed in 90 eyes (71%) on structural OCT. The qualitative OCT-A analysis revealed: tiny branching vessels in 82.5% of the cases, vascular loops in 81.7%, peripheral anastomotic arcades in 66.7% and choriocapillaris hypointense halo in 54.8%. In the univariate analysis, each OCT-A parameter showed a statistically significant correlation with exudation on structural OCT (p<0.001). The overall analysis demonstrated a sensitivity of 96.7% and a positive predictive value of 87.9%. In the multivariate analysis, a model with four criteria predicted an exudative lesion in 97.6% of cases and one with two criteria (tiny branching vessels and peripheral anastomotic arcades) in 71.2%. Conclusions The presence of tiny branching vessels and a peripheral anastomotic arcade appears to predict the lesion activity with a good accuracy and the model based on four criteria enables optimal decisions regarding retreatment in eAMD.
关键词： exudative age-related macular degeneration,optical coherence tomography angiography,treatment decisions,choroidal neovascularisations,predictive model
更新于2025-09-10 09:29:36
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Improving visualization and quantitative assessment of choriocapillaris with swept source OCTA through registration and averaging applicable to clinical systems
摘要： Choriocapillaris (CC) visualization and quantification remains challenging. We propose an innovative three-step registration and averaging approach using repeated swept source optical coherence tomography angiography (SS-OCTA) scans to conduct automatic quantitative assessment on CC. Six subjects were enrolled, each imaged at several locations with SS-OCTA from macular to equatorial regions using 3 mm × 3 mm scanning pattern. Five repeated volumes were collected for each subject. The complex optical microangiography (OMAG) algorithm was applied to identify blood flow in CC slab. An automatic three-step registration of translation, affine and B-Spline was applied to en face OCTA images of CC, followed with averaging. A fuzzy clustering approach was used to segment vasculature and flow deficits from the averaged images. The improvement in visualization of CC was evaluated and the average intercapillary distance was estimated by calculating the averaged capillary lumen spacing. A series of quantitative indices of flow deficit density, number, size, complexity index and aspect ratio index (FDD, FDN, FDS, FDCI and FDARI) were designed and validated with the increase of repeated scan numbers for averaging. Quantitative assessment was applied and compared on CC in macular and equatorial regions. The intercapillary distance was observed to be around 24 μm at macula and increased toward equatorial regions. All five quantitative indices (FDD, FDN, FDS, FDCI and FDARI) showed significant changes with multiple averaging and tend to become stable with repeated number of 4. Our proposed registration and averaging algorithm significantly improved the visualization of CC with SS-OCTA. The designed five indices for CC provide more options in the quantitative assessment of CC and are of great potentials in assisting the understanding of disease pathology, early diagnosis and treatment monitoring.
关键词： quantitative assessment,optical coherence tomography angiography,choriocapillaris,averaging,registration
更新于2025-09-10 09:29:36
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Comparison of Neovascular Lesion Area Measurements From Different Swept-Source OCT Angiographic Scan Patterns in Age-Related Macular Degeneration
摘要： PURPOSE. We compared area measurements for the same neovascular lesions imaged using swept source optical coherence tomography angiography (SS-OCTA) and enlarging scan patterns. METHODS. Patients with neovascular age-related macular degeneration were imaged using a 100-kHz SS-OCTA instrument (PLEX Elite 9000). The scanning protocols included the 3 3 3, 6 3 6, 9 3 9, and 12 3 12 mm ?elds of view. Two groups were studied. Group 1 included small lesions contained within the 3 3 3 mm scan, and Group 2 included larger lesions that were fully contained within the 6 3 6 mm scan. RESULTS. A total of 30 eyes of 26 patients were enrolled in Group 1 and 30 eyes of 25 patients were enrolled in Group 2. In Group 1, the automated mean lesion area measurements were 1.11 (SD ? 0.78), 1.14 (SD ? 0.80), and 1.27 (SD ? 0.82) mm2 for the 3 3 3, 6 3 6, and 12 3 12 mm scans, respectively (ANOVA P < 0.001; post hoc comparisons, P ? 0.184, 3 3 3 vs. 6 3 6 mm; P < 0.001 for the other two pairs). In Group 2, the automated mean lesion area measurements were 5.43 (SD ? 2.56), 5.53 (SD ? 2.48), and 5.49 (SD ? 2.65) mm2 for the 6 3 6, 9 3 9, and 12 3 12 mm scans, respectively (ANOVA P ? 0.435; post-hoc comparisons, P ? 0.062, 6 3 6 vs. 9 3 9 mm; P ? 0.553, 6 3 6 vs. 12 3 12 mm; P ? 0.654, 9 3 9 vs. 12 3 12 mm). CONCLUSIONS. The similarity in lesion area measurements across different scan patterns suggests that SS-OCTA imaging can be used to follow quantitatively the enlargement of choroidal neovascularization as the disease progresses.
关键词： neovascular AMD,optical coherence tomography angiography,swept-source OCTA,quantified measurement comparison,choroidal neovascularization
更新于2025-09-10 09:29:36