177,136 research outputs found
Ledrut R., L'espace social de la ville, problèmes de sociologie appliquée à l'aménagement urbain.
No full textCoscas Gisèle. Ledrut R., L'espace social de la ville, problèmes de sociologie appliquée à l'aménagement urbain.. In: Revue française de sociologie, 1969, 10-3. p. 395
Optical Coherence Tomography Angiography of Macular Features After Proton Beam Radiotherapy for Small Choroidal Melanoma
No full textEvaluation of pseudophakic cystoid macular edema using optical coherence tomography angiography
No full textPurpose: To compare the optical coherence tomography angiography (OCT-A) findings of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with pseudophakic cystoid macular edema (PCME) with those of fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT) and to compare PCME vascular density values of the SCP and DCP with those of healthy eyes. Methods: In this retrospective observational study, 13 eyes (12 patients) with PCME underwent comprehensive ophthalmologic examinations including visual acuity, FA, SD-OCT, and OCT-A. The vascular density of the SCP and DCP were measured using AngioAnalytics software in all PCME eyes and compared with 46 healthy eyes of 25 subjects. Results: In patients with PCME, at the level of SCP, the mean vascular density in the whole en face image was 44.48 ± 3.61% while it was 50.27 ± 5.30% at the level of the DCP. In contrast, the vascular density in the whole en face image was 50.35 ± 3.22 at the level of SCP while it was 56.15 ± 3.28 at the level of DCP in 46 healthy eyes of 25 subjects. The vascular density of patients with PCME was significantly lower than in healthy subjects at the SCP (p<0.0001) and at the DCP (p<0.0001). Conclusion: We report the OCT-A appearance of PCME and vascular density map with values that can be easily interpreted for quantitative evaluation of retina perfusion status using OCT-A. This approach might be the first step in helping us fully understand the pathophysiologic mechanisms underlying PCME
Macular optical coherence tomography angiography parameters as predictive biomarkers of peripheral retinal ischemia in treatment naive diabetic macular edema
No full textComparison of reflectivity signal obtained by Enface OCT and OCT Angiography in cystoid macular edema
No full textOptical coherence tomography angiography in exudative age-related macular degeneration: a predictive model for treatment decisions
No full textAims 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
PREDICTIVE ACTIVATION BIOMARKERS OF TREATMENT-NAIVE ASYMPTOMATIC CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION
No full textPurpose: To assess the long-term evolution of treatment-naive quiescent choroidal neovascularization (CNV), in age-related macular degeneration (AMD), to identify predictive activation biomarkers. Methods: Patients with quiescent CNV underwent a comprehensive ophthalmological examination, including fluorescein and indocyanine green angiographies, structural optical coherence tomography (OCT), and OCT angiography. Qualitative and quantitative analyses of structural OCT and OCT angiography images were performed during the study period. At the last follow-up evaluation, the enrolled eyes were divided into two groups: eyes with quiescent CNV converting to exudative AMD (eAMD) and those not progressing to eAMD. Results: Sixty-eight eyes of 68 patients were enrolled in the study. Mean follow-up duration was 40 ± 28 months using multimodal imaging and 22 ± 13 months using OCT angiography. On structural OCT, quiescent CNV not converting to eAMD showed a preferential growth of the pigment epithelium detachment greatest linear diameter (P = 0.009), whereas the eAMD group presented a preferential growth of the pigment epithelium detachment maximal height (P, 0.0001) during the study period. Quantitative analysis of choriocapillaris OCT angiograms confirmed the CNV area growth during follow-up (from 4.18 ± 4.77 mm2 at baseline to 5.10 ± 5.06 mm2 at the last follow-up visit; P = 0.02). Conclusion: A close follow-up is recommended to early identify predictive activation biomarkers of treatment-naive quiescent CNV
Multimodal OCT Reflectivity Analysis of the Cystoid Spaces in Cystoid Macular Edema
No full textPurpose. To compare and evaluate images of macular cysts with diferent degrees of refectivity (from gray to black signal) as observed in B scan spectral domain OCT (SDOCT) and EnFace OCT with decorrelation signal obtained with OCT-angiography (OCTA) in eyes with cystoid macular edema (CME) secondary to diabetic retinopathy (DR) and retinal vein occlusion (RVO). Methods.Imagesfrom 3033 patients afected by CME secondary to diabetes or RVO examined OCTA (Optovue XR Avanti, Optovue, USA) at the University Eye Clinic of Cr ́eteil, Hˆopital Intercommunal, France, and at the University Eye Clinic of Cagliari, “San Giovanni di Dio” Hospital, Italy, were retrospectively examined. Te deep capillary plexus OCTA images and the corresponding EnFace OCT images, both acquired with the same automatic segmentation, had been overlapped to compose RGB color images as red and green channels, respectively, using ImageJ sofware (National Institutes of Health, Bethesda, MD). Aferward, linear regions of interest were traced on the color images to obtain the profles of OCTA and EnFace gray values. Number of pixels, mean gray value and standard deviation of the area traced in OCT-A, and EnFace image were analyzed and statistically correlated. Data were exported to Excel to create the plots. Results. 94 patients with DME and 27 patients with RVO showed intraretinal macular cystoid spaces with similar homogeneous, gray-looking content; 73 patients with DME and 113 patients with RVO showed macular cystoid spaces with homogeneous, black-looking content, as observed at SD-OCT, EnFace and OCTA scans. Interestingly, the limits of macular cystoid spaces were clearly detectable with OCTA. Te analysis of red and green profles demonstrated a clearly visible overlap between average OCTA and EnFace signal observed around cystoid spaces that could be attributed to a relationship between the dynamic vascularization and the structural density of the tissue. Conclusions. Tis is the frst investigation that characterizes and correlates OCTA and EnFace signals on images of macular cystoid spaces in DR and RVO.Te low intensity OCTA signals observed inside cystoid spaces raise a relevant question about their nature, as to whether they are due to the presence of corpusculated material pouring out from bloodocular-barrier or they should be considered OCTA artifacts
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