102 research outputs found
Charge-Order Pattern of the Low-Temperature Phase of NaV2O5 Uniquely Determined by Resonant X-Ray Scattering from Monoclinic Single Domain
The present resonant x-ray scattering from each of monoclinically-split
single domains of NaV2O5 has critically enhanced contrast between V4+ and V5+
ions strong enough to lead to unambiguous conclusion of the charge-order
pattern of its low-temperature phase below Tc = 35 K. The zig-zag type
charge-order patterns in the -plane previously confirmed have four kinds of
configurations (A, A', B and B') and the stacking sequence along the c-axis is
determined as the AAA'A' type by comparison with model calculations. By
assigning the A and A' configurations to Ising spins, one can reasonably
understand the previously discovered "devil's staircase"-type behavior with
respect to the modulation of the layer-stacking sequences at high pressures and
low temperatures, which very well resembles the global phase diagram
theoretically predicted by the ANNNI model.Comment: 4 pages, 3 figure
Influence of vitreomacular interface score on treatment outcomes of anti-VEGF therapy for neovascular age-related macular degeneration
[Background] To quantitatively evaluate the vitreomacular interface of eyes with neovascular age-related macular degeneration (AMD) and to investigate its association with the 1-year treatment outcome following intravitreal injections of aflibercept (IVA). [Methods] This prospective observational case series included 59 eyes of 59 consecutive patients with treatment-naïve neovascular AMD who were treated with three monthly IVA and subsequent four bi-monthly IVA and were followed up for 1 year. We estimated posterior vitreous detachment at 1, 9, and 25 macular points within an area of 6 × 6 mm2 at the center of the fovea using the built-in enhanced vitreous visualization mode of swept-source optical coherence tomography. One year after the initial IVA, we classified the eyes into either wet or dry groups. [Results] The wet and dry groups included 12 and 47 eyes, respectively. The resistance rate against IVA was 20.3%. The 25-point interface score was higher in the wet group than in the dry group (23.0 ± 4.3 vs. 18.6 ± 9.8, P = 0.03), whereas there were no significant between-group differences in the 9-point and 1-point scores (P = 0.21, and 0.47, respectively) or in the other studied parameters. Multivariable analysis revealed that the 25-point vitreomacular interface score was strongly correlated with subfoveal choroidal thickness (P = 0.02, β = − 0.31). [Conclusions] Our findings suggest that wide-ranged separation of the posterior vitreous membrane from the retina induces poor response to IVA
Natural Course of Pachychoroid Pigment Epitheliopathy
PURPOSE: To investigate the natural course of pachychoroid pigment epitheliopathy (PPE). DESIGN: A retrospective cohort study. SUBJECTS: From the Kyoto central serous chorioretinopathy (CSC) cohort consisting of 548 patients with CSC as of September 2020, we included consecutive unilateral patients with acute or chronic CSC between January 2013 and December 2016. METHODS: All patients underwent complete ophthalmic examination, including multimodal imaging such as fundus autofluorescence, spectral-domain optical coherence tomography, and fluorescein angiography/indocyanine green angiography and/or optimal coherence tomography angiography. The fellow eyes of eyes diagnosed with CSC were screened for PPE, and their natural course was evaluated. We also evaluated the association of ARMS2 rs10490924, CFH rs800292, TNFRSF10A rs13278062, and GATA5 rs6061548 genotypes with the natural course. MAIN OUTCOME MEASURES: Incidence of CSC, pachychoroid neovasculopathy, and pachychoroid geographic atrophy (GA). RESULTS: In total, 165 patients with unilateral CSC (mean age, 55.7 ± 12.6 years; female, 22.4%) were included from the Kyoto CSC cohort. Among them, 148 (89.7%) were diagnosed as having PPE in their non-CSC eye. Survival analysis revealed that 16.8% of PPE eyes developed CSC during the 6-year follow up, whereas non-PPE eyes did not. Although genetic factors did not have significant association with CSC development (P > 0.05, log-rank test), choroidal vascular hyperpermeability (CVH) and subfoveal choroidal thickness (SFCT) were significantly associated with CSC incidence (P = 0.001, log-rank test). Survival analysis showed that eyes without CVH and eyes with SFCT < 300 μm did not develop CSC during the 6-year follow-up. Pachychoroid neovasculopathy developed in only 1 eye with PPE during a follow-up of 46.4 months. Pachychoroid GA did not develop in any of the studied eyes. CONCLUSIONS: This study revealed a natural history of PPE in a relatively large Japanese cohort. Choroidal vascular hyperpermeability and SFCT were significant risk factors for the development of CSC in PPE eyes. Although the current results cannot be generalized for all eyes with PPE, these findings present an important clinical implication
Short-term variation in pH in seawaters around coastal areas of Japan: characteristics and forcings
The pH of coastal seawater varies based on several local forcings, such as water circulation, terrestrial inputs, and biological processes, and these forcings are changing along with global climate change. Understanding the mechanism of pH variation in each coastal area is thus important for a realistic future projection that considers changes in these forcings. From 2020 to 2021, we performed parallel year-round observations of pH and related ocean parameters at five stations around the Japanese coast (Miyako Bay, Shizugawa Bay, Kashiwazaki Coast, Hinase Archipelago, and Ohno Strait) to understand the characteristics of short-term pH variations and their forcings. Annual variability (∼ 1 standard deviation) of pH and aragonite saturation state (Ωar) were 0.05–0.09 and 0.25–0.29, respectively, for three areas with low anthropogenic pressures (Miyako Bay, Kashiwazaki Coast, and Shizugawa Bay), while it increased to 0.16–0.21 and 0.52–0.58, respectively, in two areas with medium anthropogenic pressures (Hinase Archipelago and Ohno Strait in Seto Inland Sea). Statistical assessment of temporal variability at various timescales revealed that most of the annual variabilities in both pH and Ωar were derived by short-term variation at a timescale of <10 d, rather than seasonal-scale variation. Our analyses further illustrated that most of the short-term pH variation was caused by biological processes, while both thermodynamic and biological processes equally contributed to the temporal variation in Ωar. The observed results showed that short-term acidification with Ωar < 1.5 occurred occasionally in Miyako and Shizugawa bays, while it occurred frequently in the Hinase Archipelago and Ohno Strait. Most of such short-term acidified events were related to short-term low-salinity events. Our analyses showed that the amplitude of short-term pH variation was linearly correlated with that of short-term salinity variation, and its regression coefficient at the time of high freshwater input was positively correlated with the nutrient concentration of the main river that flows into the coastal area.</p
Effectiveness of Reduced-fluence Photodynamic Therapy for Chronic Central Serous Chorioretinopathy
[Purpose] To investigate the 2-year effectiveness of reduced-fluence photodynamic therapy (rf-PDT) for chronic central serous chorioretinopathy (cCSC). [Design] Retrospective cohort study. [Participants] A total of 223 consecutive patients with newly diagnosed cCSC with active serous retinal detachment (SRD) were included from May 2007 to June 2017 and followed up for at least 2 years. Patients who underwent ocular treatment other than cataract surgery before the beginning of recruitment and those who had macular neovascularization at baseline were excluded. [Methods] All patients underwent a comprehensive ophthalmic evaluation, including measurements of best-corrected visual acuity (BCVA), slit-lamp examination, dilated fundus examination, color fundus photography, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, and spectral-domain OCT. An inverse probability of treatment weighting (IPTW) methodology was applied to balance 18 baseline characteristics between patients who received rf-PDT (rf-PDT group) and those who did not receive treatment (controls). Inverse probability of treatment weighting survival analysis and regression were performed. [Main Outcome Measures] The proportion of patients whose BCVA at 24 months was the same or improved compared with the baseline visual acuity (VA) (VA maintenance rate). [Results] A total of 155 eyes (rf-PDT group: 74; controls: 81) were analyzed. The patients’ backgrounds were well balanced after IPTW with standardized differences of < 0.10. An IPTW regression analysis revealed that the VA maintenance rate was significantly higher in the rf-PDT group than in the controls (93.6% vs. 70.9%, P < 0.001, 12 months; 85.7% vs. 69.8%, P = 0.019, 24 months). The rf-PDT group tended to show better VA improvement, but was not statistically significant (–0.06 vs. –0.008, P = 0.07, 12 months; –0.06 vs. –0.03, P = 0.32, 24 months). An IPTW Cox regression showed a significantly higher rate of complete SRD remission in the rf-PDT group (hazard ratio, 5.05; 95% confidence interval, 3.24–7.89; P < 0.001). [Conclusions] The study suggests the beneficial effect of rf-PDT for cCSC for both VA maintenance and higher proportion of complete SRD remission in the clinical setting
Distribution of Choroidal Thickness and Choroidal Vessel Dilation in Healthy Japanese Individuals: The Nagahama Study
[Purpose] To report fundamental epidemiologic data for choroidal parameters such as choroidal thickness and index of choroidal vascularity in Japanese individuals and to evaluate their correlations with age, sex, systemic parameters, and other ocular parameters. [Design] Population-based cohort study. [Participants] A total of 9850 individuals participated in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama Study) conducted between 2013 and 2016. [Methods] All participants underwent standardized ophthalmic examinations, including OCT with enhanced depth imaging (EDI; RS-3000 Advance; Nidek). We manually segmented the choroidoscleral interface to measure subfoveal choroidal thickness (SFCT) and calculated the normalized choroidal intensity obtained with EDI (NCIEDI) and choroidal vascularity index (CVI). These are indices of choroidal brightness in OCT and reportedly represent the dilation of choroidal vessels. After summarizing the age-sex stratified distributions of SFCT, NCIEDI, and CVI, their associations with age, sex, axial length (AL), and spherical equivalent (SE) were evaluated using linear regression analysis with adjustments for possible confounders. [Main Outcome Measures] Distribution of SFCT, NCIEDI, and CVI in the healthy Japanese population and their characteristics. [Results] Age-sex standardized SFCT, NCIEDI, and CVI were 291.2 μm, 0.653, and 66.88%, respectively. In both men and women, SFCT was associated negatively with age (P < 0.001) and NCIEDI was associated positively with age (P < 0.001). Although both SFCT and NCIEDI did not differ significantly between men and women overall (P = 0.87 and P = 0.21, respectively), among younger participants (35–50 years of age), men showed significantly greater SFCT than women (P < 0.001). Only in men was CVI associated positively with age (P < 0.001). In the multivariable analysis, SFCT was associated significantly with age, sex, AL, SE, and the interaction term of age and sex (P < 0.001). Independent of SFCT, NCIEDI and CVI were associated significantly with age (P < 0.001). [Conclusions] We report normative Japanese SFCT, NCIEDI, and CVI data using a large general Japanese cohort. The association analysis of SFCT with NCIEDI and CVI suggested that younger individuals have a more lumen-rich choroid for their choroidal thickness than older individuals
Choroidal vasculature in bietti crystalline dystrophy with CYP4V2 mutations and in retinitis pigmentosa with EYS mutations
Purpose: We compare the choroidal vascular area between Bietti crystalline dystrophy (BCD) patients with CYP4V2 mutations, retinitis pigmentosa (RP) patients with EYS mutations, and normal controls, and investigate the correlation between choroidal vascular area and associated parameters. Methods: This prospective case-series study included consecutive nine eyes of nine BCD patients with CYP4V2 mutations (BCD group), 16 eyes of 16 RP patients with EYS mutations (EYS-RP group), and 16 eyes of 16 normal volunteers matched for age and axial length (control group). Using swept-source optical coherence tomography, we obtained en face images of the choroidal vasculature at the midpoint of the choriocapillaris layer--Sattler's layer (inner choroid) and Haller's layer (outer choroid). After binarization, we compared the inner and outer choroidal vascular areas among the three groups and identified associated factors. Results: The outer choroidal vascular area was 43.34 ± 5.76%, 53.73 ± 4.92%, and 52.80 ± 4.10% in the BCD, EYS-RP, and control groups, respectively. This value was significantly smaller in the BCD group than in the EYS-RP and control groups (P < 0.001 in both; no significant difference between the EYS-RP and control groups). In the BCD group, the outer choroidal vascular area was correlated strongly with the subfoveal inner choroidal thickness (P = 0.001, r = 0.91, respectively). The inner choroidal vasculature could not be identified in eight of nine eyes in the BCD group. Conclusions: The outer choroidal vascular narrowing might progress with the inner choroidal thinning in BCD, and the inner choroidal vasculature might be extinguished in advanced-stage BCD. Our findings may help to clarify the etiology of BCD
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