We study the nature of edge states in extrinsically and spontaneously dimerized states of two-dimensional spin-$\frac{1}{2}$ antiferromagnets, by performing quantum Monte Carlo simulation. We show that a gapless edge mode emerges in the wide region of the dimerized phases, and the critical exponent of spin correlators along the edge deviates from the value of Tomonaga-Luttinger liquid (TLL) universality in large but finite systems at low temperatures. We also demonstrate that the gapless nature at edges is stable against several perturbations such as external magnetic field, easy-plane XXZ anisotropy, Dzyaloshinskii-Moriya interaction, and further-neighbor exchange interactions. The edge states exhibit non-TLL behavior, depending strongly on model parameters and kinds of perturbations. Possible ways of detecting these edge states are discussed. Properties of edge states we show in this paper could also be used as reference points to study other edge states of more exotic gapped magnetic phases such as spin liquids.

Objective This study aimed to investigate the anatomical and functional changes in patients with central retinal artery occlusion (CRAO) (n=21) treated with 10 µg/day intravenous liposomal prostaglandin E1 (lipo-PGE1). Methods and analysis We used best-corrected visual acuity (BCVA), central retinal thickness with spectral domain optical coherence photography, optical intensity ratio (OIR) with imageJ software and retinal vessel diameter with fundus photography as indicators. Data were analysed using Tukey’s multiple comparisons, Wilcoxon test or Spearman’s correlation analysis as appropriate. Results BCVA was significantly improved at 1 month and 3 months after the initial visit (from 2.18±0.60 to 1.54±0.84 and 1.53±0.88, p=0.030 and p=0.027, respectively). The ratio of retinal vein diameter to optic disc diameter increased in the first month (from 0.40%±0.13% to 0.52%±0.16%, p=0.005). In addition, the OIR at the initial visit was significantly correlated with BCVA at 3 months (p=0.006, r=0.58). No severe adverse effects were observed. Conclusion The results showed that visual acuity and retinal vein constriction improved after lipo-PGE1 therapy. In addition, the OIR in the initial phase can be an indicator of visual prognosis after treatment with PGE1 in patients with CRAO.

We investigated whether foveal ellipsoid zone (EZ) status affects visual prognosis in eyes with subretinal fluid (SRF) associated with branch retinal vein occlusion (BRVO). We included 38 eyes retrospectively and classified those with or without a continuous EZ on the SRF of the central foveola on the vertical optical coherence tomography (OCT) image at the initial visit as intact (n = 26) and disruptive EZ (n = 12) groups, respectively. In addition, we classified the intact EZ eyes into clear (n = 15) and blurred (n = 11) EZ groups according to whether EZ on the SRF was observed distinctly or not. Multiple regression analyses showed that baseline EZ status significantly correlated (p = 0.0028) with the 12-months logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), indicating that baseline intact EZ significantly improves visual prognosis. The 12-months logMAR BCVA of the intact EZ group was significantly better (p < 0.001) than that of the disruptive EZ group, and did not differ significantly between the clear and blurred EZ groups. Thus, baseline foveal EZ status on vertical OCT images can be a novel biomarker for visual prognosis in eyes with SRF associated with BRVO.

We compared the visibility and surgeon posture between image-processing-assisted trabeculotomy (IP-LOT) using the NGENUITY^® 3D visual system and conventional microsurgery (microscope-assisted trabeculotomy; MS-LOT). IP-LOT was performed for five pig eyes. The visibility of the trabecular mesh work was evaluated on images of the trabecular mesh work and the posterior surface of the cornea (Cor) obtained under three different conditions. Images were then analyzed using ImageJ^® to measure differences in luminance between the trabecular mesh work and Cor. IP-LOT was also performed for eleven human eyes, and the data were analyzed using the same approach as that used for the pig eyes. The length from the surgeon’s abdomen to the operative eye (working distance) during MS-LOT and IP-LOT was measured for 12 different surgeons and compared to evaluate surgeon posture. Image processing significantly increased the difference in luminance between the trabecular mesh work and Cor in both pig and human eyes (p < 0.05). Moreover, the working distance in IP-LOT was significantly shorter than that in MS-LOT (p < 0.05). Our findings suggest that the NGENUITY^® 3D visual system provides better trabecular mesh work visibility than a normal microscope in conventional surgical methods, and it allows surgeons to operate without moving far from the operative eye.

We present a rare case of acute retinal pigment epitheliitis (ARPE) following vaccination. An 18-year-old Japanese man visited our hospital with a 5-day history of a central scotoma in the right eye. He had received the second dose of coronavirus disease 2019 vaccination (BNT162b2 mRNA, Pfizer-BioNTech) 1 month prior, following which he developed a low-grade fever of 37.3–37.5°C for 2 days accompanied by joint pain. Although he had received influenza vaccination 5 days prior to this presentation, no systemic symptoms other than injection site pain were observed. Blood test results were unremarkable. Ophthalmological examination revealed a decimal best-corrected visual acuity (BCVA) of 0.8 and 1.2 in the right and left eyes, respectively. Intraocular pressure was 15 mm Hg in both eyes. Intraocular inflammation was not observed. Fundus examination revealed a localized lesion of pigment stippling associated with yellowish hypopigmentation in the fovea. Fluorescein angiography revealed slight transmission hyperfluorescence without leakage. Optical coherence tomography (OCT) revealed disruption of the external limiting membrane (ELM), ellipsoid zone (EZ), and interdigitation zone (IZ). We diagnosed the patient with ARPE in the right eye. The patient was followed up without treatment. Five weeks after onset, the central scotoma in the right eye disappeared, and patient’s BCVA in the right eye improved to 1.5. OCT showed improvement in ELM and EZ continuity in the right eye, but IZ remained disruptive. Although the exact pathophysiology of the association between ARPE and these vaccinations is unclear, ARPE may develop after the vaccination.