273 research outputs found
Grid photocoagulation combined with intravitreal bevacizumab for recurrent macular edema associated with retinal vein occlusion
Purpose: To report the efficacy of grid photocoagulation combined with intravitreal bevacizumab (IVB) for macular edema recurring after previous IVBs associated with retinal vein occlusion (RVO). Methods: This retrospective study consisted of 19 eyes with branch retinal vein occlusion (BRVO) and nine eyes with central retinal vein occlusion (CRVO), which were treated with grid photocoagulation combined with IVB for recurrent macular edema after previous IVBs. The mean duration of total follow-up was 29.3 ± 5.8 months. Results: After this combination therapy, foveal thickness was reduced, significant with slight improvement in visual acuity (VA). At 1 month after treatment, although 25 of the 28 eyes showed complete resolution of the cystoid space, the macular edema recurred to some extent in 19 eyes. Compared with initial values, final foveal thickness was reduced significantly in both BRVO and CRVO groups (P < 0.001), but improvement in VA was significant only for eyes with BRVO (P = 0.012). The total number of IVB was 2.8 ± 0.7 for eyes with either BRVO or CRVO. Conclusion: Grid photocoagulation combined with IVB has a substantial effect on reducing recurrent macular edema associated with RVO, but the effect on visual acuity is limited
Hemodynamic and structural changes in retinal arterial macroaneurysm after intravitreal anti-vascular endothelial growth factor injection
High resolution imaging with optical coherence tomography angiography and offset pinhole adaptive optics scanning light ophthalmoscope helped us visualize the hemodynamic and structural changes in a ruptured retinal arterial macroaneurysm in a 78-year-old woman. Intravitreal injection of anti-vascular endothelial growth factor was administered to ameliorate the condition
Characteristics of Dredged Sludges by Desiccation
To examine the possible reuse of dredged sludge in view of construction material, physico-chemical properties and geotechnical characteristics of desiccated sludge are investigated through laboratory experiments. The consistency test, the pH test, the XRF test and the X-ray diffraction analysis are carried out for physico-chemical proteries, and the conolidation test and the permeability test are made for geotechnical characteristics. It is concluded that the history of desiccation changes the consistency of sludge and affects its permeability and consolidation bahavior
Peripheral Chorioretinal Imaging Through a Front Prism on Optical Coherence Tomography Angiography
Purpose: To evaluate the clinical feasibility of peripheral chorioretinal imaging through a front prism on swept-source optical coherence tomography angiography (SS-OCTA). Methods: We prospectively obtained en face OCTA images using SS-OCTA in 10 eyes of 10 healthy volunteers. For the peripheral chorioretinal imaging, the scanning laser passed and refracted through a 45 −90 −45 right-angle prism. We evaluated the qualitative and quantitative characteristics of chorioretinal vessels in the periphery. Results: Using peripheral chorioretinal imaging through a prism, the retinal vasculature was delineated to the equator on the OCTA images, and varices of the vortex vein ampullae were observed on choroidal OCT images. The 3×3-mm images revealed three-dimensional morphologies unique to the peripheral vasculature, such as the gap between retinal arterioles and venules in the superficial capillary plexus (SCP) and elliptical and greater lobules in the choriocapillaris layer. Compared with OCTA images obtained without the prism, those obtained through the prism demonstrated an approximately 1.24-fold increase in the lengths in the base apex direction, whereas the lengths in the perpendicular direction showed concordance. The peripheral vessel density (VD) in the inferior quadrant was lower than those in the other quadrants on the SCP and deep capillary plexus, whereas on the SCP images of the macula the lowest VD was observed in the temporal subfield. Conclusions: Peripheral chorioretinal imaging allowed us to generate ultra-widefield panoramic OCTA images and demonstrated morphologic characteristics unique to peripheral chorioretinal vessels. Translational Relevance: OCTA imaging through a front prism can be a technique for acquiring chorioretinal vasculature images in the periphery
Retinal arterial macroaneurysm rupture caused by dissection-like change in the vessel wall
[Purpose] To highlight a potential pathogenetic mechanism of retinal arterial macroaneurysm. [Observations] A 79-year-old woman presented with a ruptured retinal arterial macroaneurysm in the right eye. One year after treatment, high-resolution multimodal imaging with optical coherence tomography (OCT), OCT angiography, and adaptive optics scanning light ophthalmoscope showed that a narrow passage developed in the vessel wall of the pre-existing retinal arterial macroaneurysm and another macroaneurysm had developed adjacent to the pre-existing one. [Conclusions and Importance] These images suggest the pathogenesis of retinal arterial macroaneurysm (RAM) associated with crack-like changes in the retinal arterial wall, similar to pathologies seen in systemic arteries
Clinical Relevance of Parafoveal Intercapillary Spaces and Foveal Avascular Zone in Diabetic Retinopathy Without Macular Edema
Purpose: To investigate the clinical significance of intercapillary spaces on swept source optical coherence tomography angiography images in diabetic retinopathy. Methods: We retrospectively reviewed 110 eyes of 110 patients suffering from diabetic retinopathy without macular edema for whom 3 × 3 mm swept source optical coherence tomography angiography images centered on the fovea were obtained. Automatic image processing of the superficial slab images allowed us to define the areas encircled by retinal vessels as intercapillary spaces within the central 2-mm circle. We evaluated how the quantitative parameters of intercapillary spaces are associated with logMAR and feasible to diagnose diabetic macular ischemia. Results: Total counts (ρ = −0.419; P < 0.001) rather than morphologic parameters of the intercapillary spaces showed a significant correlation with logMAR. There were individual levels of correlations between logMAR and counts of intercapillary spaces in individual sectors. In particular, the summed numbers of the spaces in three highly significant sectors were more significantly associated with logMAR (ρ = −0.515; P < 0.001). Multivariate analyses confirmed that the number of the intercapillary spaces (β = −0.266; P = 0.016) and foveal avascular zone area (β = 0.227; P = 0.042) were related to logMAR. The clustering using the foveal avascular zone area and the number of intercapillary spaces revealed two major clusters; one had fewer intercapillary spaces (P < 0.001) and poorer logMAR (P < 0.001) than the other, with a wide range of the foveal avascular zone area. Conclusions: Decreased intercapillary spaces contribute to visual impairment in diabetic retinopathy and suggest one possible criterion of objective diagnosis of diabetic macular ischemia
White dots as a novel marker of diabetic retinopathy severity in ultrawide field imaging
Purpose: To characterize white dots in diabetic retinopathy (DR) and their association with disease severity using ultra-wide-field scanning laser ophthalmoscopy. Methods: We randomly selected 125 eyes of 77 patients (25 eyes from individual categories of the international classification of DR severity) for which ultrawide field photographs were obtained. We characterized white dots, which were delineated by higher signal levels on green but not red laser images, and evaluated the relationship between the number of white dots and the international severity scale of DR. Results: Most white dots were located in nonperfused areas, and the number of total white dots was significantly correlated to that of dots in nonperfused areas. White dots corresponded to microaneurysms around the boundary between nonperfused areas and perfused areas or unknown lesions in nonperfused areas. Eyes with DR had significantly more white dots than those with no apparent retinopathy. The numbers of white dots in moderate nonproliferative diabetic retinopathy (NPDR) or more severe grades were significantly higher than in mild NPDR. The area under the receiver operating characteristics curve (AROC) analyses demonstrated that the number of white dots had the significance in the diagnosis of DR (0.908-0.986) and moderate NPDR or more severe grades (0.888-0.974). Conclusions: These data suggest the clinical relevance of white dots seen on ultrawide field images in the diagnosis of the severity of DR
The intercapillary space spectrum as a marker of diabetic retinopathy severity on optical coherence tomography angiography
Microcirculatory disturbance plays a pivotal role in the pathogenesis in diabetic retinopathy (DR). We retrospectively quantified the total counts and morphological features of intercapillary spaces, i.e., intercapillary areas and nonperfusion areas (NPAs), on swept-source optical coherence tomography angiography (SS-OCTA) images and to evaluate their associations with DR severity grades. We acquired 3 × 3 mm OCTA images in 75 eyes of 62 diabetic patients and 22 eyes of 22 nondiabetic subjects. In the en-face superficial images within the central 2 mm, the areas enclosed by retinal vessels were automatically detected. Their total numbers decreased in some eyes with no apparent retinopathy and most eyes with DR, which allowed us to discriminate diabetic subjects from nondiabetic subjects [area under the receiver operating characteristic curve (AUC) = 0.907]. The areas and area/perimeter ratios continuously increased in DR, indicating a continuum between healthy intercapillary areas and NPAs. The number of intercapillary spaces with a high area/perimeter ratio increased according to DR severity, which showed modest performance in discriminating moderate NPDR or higher grades (AUC = 0.868). These quantified parameters of intercapillary spaces can feasibly be used for the early detection of microcirculatory impairment and the diagnosis of referable DR
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