Active and inactive microaneurysms identified and characterized by structural and angiographic optical coherence tomography

Purpose: To characterize flow status within microaneurysms (MAs) and quantitatively investigate their relations with regional macular edema in diabetic retinopathy (DR). Design: Retrospective, cross-sectional study. Participants: A total of 99 participants, including 23 with mild nonproliferative DR (NPDR), 25 with moderate NPDR, 34 with severe NPDR, 17 with proliferative DR. Methods: In this study, 3x3-mm optical coherence tomography (OCT) and OCT angiography (OCTA) scans with a 400x400 sampling density from one eye of each participant were obtained using a commercial OCT system. Trained graders manually identified MAs and their location relative to the anatomic layers from cross-sectional OCT. Microaneurysms were first classified as active if the flow signal was present in the OCTA channel. Then active MAs were further classified into fully active and partially active MAs based on the flow perfusion status of MA on en face OCTA. The presence of retinal fluid near MAs was compared between active and inactive types. We also compared OCT-based MA detection to fundus photography (FP) and fluorescein angiography (FA)-based detection. Results: We identified 308 MAs (166 fully active, 88 partially active, 54 inactive) in 42 eyes using OCT and OCTA. Nearly half of the MAs identified straddle the inner nuclear layer and outer plexiform layer. Compared to partially active and inactive MAs, fully active MAs were more likely to be associated with local retinal fluid. The associated fluid volumes were larger with fully active MAs than with partially active and inactive MAs. OCT/OCTA detected all MAs found on FP. While not all MAs seen with FA were identified with OCT, some MAs seen with OCT were not visible with FA or FP. Conclusions: Co-registered OCT and OCTA can characterize MA activities, which could be a new means to study diabetic macular edema pathophysiology

Basic research and clinical investigations of the neural basis of orofacial pain

Background: Trigeminal nerve injury or orofacial inflammation causes severe pain in the orofacial regions innervated by uninjured nerves or uninflamed tissues as well as injured or inflamed tissues. Pathological orofacial pain associated with trigeminal nerve injury or inflammation is difficult to diagnose and treat. Highlights: To develop appropriate treatments for patients with orofacial pathological pain, various animal models of trigeminal nerve injury or orofacial inflammation have been developed. Further, the possible mechanisms involving the trigeminal ganglion (TG), trigeminal spinal subnucleus caudalis (Vc), and upper cervical spinal cord (C1-C2) have been studied. Conclusions: 1) Neurotransmitters released from the somata of TG neurons are involved in peripheral sensitization. 2) Neurotransmitter release from TG neurons is decreased by botulinum toxin-type A administration, suggesting that this toxin suppressed neurotransmitter release and alleviated the neuropathic pain-related behavior. 3) Altered states of glial cells and nociceptive neurons, in the Vc and C1-C2 are involved in pathological orofacial pain associated with trigeminal nerve injury or orofacial inflammation. 4) The trigeminal sensory nuclear complex, especially the trigeminal spinal subnucleus oralis, is involved in normal and pathological orofacial pain conditions after peripheral nerve injury. 5) Neuroimaging analyses have suggested functional changes in the central and peripheral nervous systems in neuropathic pain conditions

Background Factors Affecting Visual Acuity at Initial Visit in Eyes with Central Retinal Vein Occlusion : Multicenter Study in Japan

Purpose: To determine the baseline characteristics of patients with central retinal vein occlusion (CRVO) that were significantly associated with the best-corrected visual acuity (BCVA) at the initial examination. Methods: This was a retrospective multicenter study using the medical records registered in 17 ophthalmological institutions in Japan. Patients with untreated CRVO (≥20-years-of-age) who were initially examined between January 2013 and December 2017 were studied. The patients’ baseline factors that were significantly associated with the BCVA at the initial examination were determined by univariate and multivariate linear regression analyses. Results: Data from 517 eyes of 517 patients were analyzed. Univariate analyses showed that an older age (r = 0.194, p < 0.001) and the right eye (r = −0.103, p < 0.019) were significantly associated with poorer BCVA at the initial visit. Multivariate analyses also showed that an older age (β = 0.191, p < 0.001) and the right eye (β = −0.089, p = 0.041) were significantly associated with poorer BCVA at the initial visit. Conclusions: The results indicate that an older age, a known strong factor, and the right eye were significantly associated with poorer BCVA at the initial visit to the hospital. These results suggest that functional and/or anatomical differences between the right and left eyes may be involved in these results

出生時低体重の小児における腎生検所見の特徴

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Linear and nonlinear optical properties of aggregated spherical gold nanoparticles

We have fabricated gold nanospheres composite multilayer films using the layer-by-layer (LbL) self-assembly technique, and have investigated the aggregate states of the gold nanosphere. The gold nanospheres composite multilayer films were fabricated by controlling the gold nanosphere layers with polyelectrolyte layers, and were characterized with linear and nonlinear optical spectroscopy. The transmission absorption spectra and scanning electron microscopy (SEM) images show modifications of the optical properties arising from the aggregate states of the gold nanospheres. The strong longitudinal resonance mode was observed when the gold nanospheres form aggreagates. Intense optical second-harmonic generation (SHG) was observed from the gold nanosphere aggregates of which surface was covered with a hemicyanine self-assembled monolayer. This high SHG response originates from the strong interaction via localized surface plasmon enhancement of the gold nanosphere aggregates. The gold nanosphere aggregates are promising for applications to optoelectronic devices and surface-enhanced spectroscopy

Sequential Observations of Conversion from Nonischemic to Ischemic Central Retinal Vein Occlusion Using Optical Coherence Tomography Angiography

We report the sequential changes of retinal vessels observed by optical coherence tomography angiography (OCTA) in a case of nonischemic central retinal vein occlusion (CRVO) that converted to ischemic CRVO. An 81-year-old woman visited our Retina Clinic because of visual acuity loss in the left eye. Funduscopic examination showed venous tortuosity and intraretinal hemorrhage in all four quadrants of the fundus. OCT showed macular edema. Fluorescein angiography (FA) and OCTA showed loss of small capillaries. Nonischemic CRVO was diagnosed. Antivascular endothelial growth factor (VEGF) treatment resolved the edema and improved visual acuity. However, during follow-up, capillary dropout was observed on OCTA, which gradually enlarged. Eventually, FA confirmed the conversion to ischemic CRVO. In this case, sequential observations using OCTA showed that nonischemic CRVO did not convert to ischemic CRVO abruptly but occurred stepwise. Additionally, vascular changes began around the veins and blood flow changes were observed more clearly in deep capillary plexus than in superficial capillary plexus