The Effect of β-Blocker Eye Drops on Pulse Rate, Ocular Blood Flow, and Glaucoma Progression: A Retrospective Longitudinal Study

INTRODUCTION

Our study was conducted to determine factors associated with the effectiveness of a β-blocker eye drop add-on in altering pulse rate (PR) in glaucoma patients.

METHODS

This retrospective study examined 236 eyes of 138 patients who received a β-blocker eye drop add-on during follow-up. Patients were included if at least one PR measurement was available both before and after the add-on was started. We collected data on ophthalmic parameters: longitudinal PR; longitudinal choroidal blood flow, represented by laser speckle flowgraphy-measured mean blur rate (MBR); and diacron-reactive oxygen metabolites (d-ROMs). We used a multivariable linear mixed-effects model to investigate the effectiveness of the β-blocker eye drop add-on in altering PR and examined factors contributing to a larger PR alteration after the add-on was started by analyzing the effect on PR of the interaction term between the add-on and clinical factors. We used the k-means method to classify the patients.

RESULTS

The β-blocker eye drop add-on reduced PR (- 7.61 bpm, P < 0.001). Female gender, higher PR when the add-on was started, lower central corneal thickness, and a higher d-ROM level were associated with greater reduction in PR (P < 0.05). In a cluster of patients with these clinical features, choroidal MBR increased by + 3.42% when we adjusted for change over time; MD slope, which represents the speed of glaucoma progression, improved by + 0.64 dB/year (P < 0.05).

CONCLUSIONS

We identified a glaucoma subgroup in which PR decreased, choroidal blood flow increased, and glaucoma progression slowed after a β-blocker eye drop add-on was started.

Neurovascular dysfunction in glaucoma

Retinal ganglion cells, the neurons that die in glaucoma, are endowed with a high metabolism requiring optimal provision of oxygen and nutrients to sustain their activity. The timely regulation of blood flow is, therefore, essential to supply firing neurons in active areas with the oxygen and glucose they need for energy. Many glaucoma patients suffer from vascular deficits including reduced blood flow, impaired autoregulation, neurovascular coupling dysfunction, and blood-retina/brain-barrier breakdown. These processes are tightly regulated by a community of cells known as the neurovascular unit comprising neurons, endothelial cells, pericytes, Müller cells, astrocytes, and microglia. In this review, the neurovascular unit takes center stage as we examine the ability of its members to regulate neurovascular interactions and how their function might be altered during glaucomatous stress. Pericytes receive special attention based on recent data demonstrating their key role in the regulation of neurovascular coupling in physiological and pathological conditions. Of particular interest is the discovery and characterization of tunneling nanotubes, thin actin-based conduits that connect distal pericytes, which play essential roles in the complex spatial and temporal distribution of blood within the retinal capillary network. We discuss cellular and molecular mechanisms of neurovascular interactions and their pathophysiological implications, while highlighting opportunities to develop strategies for vascular protection and regeneration to improve functional outcomes in glaucoma.

Optical Coherence Tomography and Optical Coherence Tomography Angiography: Essential Tools for Detecting Glaucoma and Disease Progression

Early diagnosis and detection of disease progression are critical to successful therapeutic intervention in glaucoma, the leading cause of irreversible blindness worldwide. Optical coherence tomography (OCT) is a non-invasive imaging technique that allows objective quantification in vivo of key glaucomatous structural changes in the retina and the optic nerve head (ONH). Advances in OCT technology have increased the scan speed and enhanced image quality, contributing to early glaucoma diagnosis and monitoring, as well as the visualization of critically important structures deep within the ONH, such as the lamina cribrosa. OCT angiography (OCTA) is a dye-free technique for noninvasively assessing ocular microvasculature, including capillaries within each plexus serving the macula, peripapillary retina and ONH regions, as well as the deeper vessels of the choroid. This layer-specific assessment of the microvasculature has provided evidence that retinal and choroidal vascular impairments can occur during early stages of glaucoma, suggesting that OCTA-derived measurements could be used as biomarkers for enhancing detection of glaucoma and its progression, as well as to reveal novel insights about pathophysiology. Moreover, these innovations have demonstrated that damage to the macula, a critical region for the vision-related quality of life, can be observed in the early stages of glaucomatous eyes, leading to a paradigm shift in glaucoma monitoring. Other advances in software and hardware, such as artificial intelligence-based algorithms, adaptive optics, and visible-light OCT, may further benefit clinical management of glaucoma in the future. This article reviews the utility of OCT and OCTA for glaucoma diagnosis and disease progression detection, emphasizes the importance of detecting macula damage in glaucoma, and highlights the future perspective of OCT and OCTA. We conclude that the OCT and OCTA are essential glaucoma detection and monitoring tools, leading to clinical and economic benefits for patients and society.

Vasoreactivity of the optic nerve head, nailfold, and facial skin in response to cold provocation in normal-tension glaucoma patients

BACKGROUND

The dysfunction of optic nerve head (ONH) hemodynamics has been suggested to be involved in the pathogenesis of normal-tension glaucoma (NTG). The aim of this study was to compare vasoreactivity in the ONH, nailfold, and facial skin in response to cold-water provocation in NTG patients and healthy controls.

METHODS

We performed cold-water provocation in 14 eyes of 14 NTG patients and 15 eyes of 15 age-matched control subjects. Laser speckle flowgraphy-derived tissue-area mean blur rate (MT), skin blood flowmetry-derived pulse wave amplitude (PA), nailfold capillaroscopy-derived nailfold capillary diameter, and other clinical parameters were recorded at baseline and 4 and 6 min after the cold stimulus. We compared changes (as percentages) in these variables in the NTG and control subjects with a linear mixed-effects model and evaluated correlations between these changes with Spearman's rank correlation coefficient.

RESULTS

The interaction term between the NTG group (reference, control group) and the 4-min protocol step (reference, baseline) significantly affected the changes in MT, nailfold capillary diameter and PA (β = -9.51%, P = 0.017, β = -20.32%, P = 0.002; β =  + 18.06%, P = 0.017, respectively). The change in MT was positively correlated with the change in nailfold capillary diameter, and negatively correlated with the change in PA (r = 0.39, P = 0.036; r = -0.40, P = 0.031, respectively).

CONCLUSION

NTG patients showed abnormal vasoconstriction in the ONH and nailfold and vasodilation in the facial skin in response to cold-water provocation.

Large-scale multitrait genome-wide association analyses identify hundreds of glaucoma risk loci

Glaucoma, a leading cause of irreversible blindness, is a highly heritable human disease. Previous genome-wide association studies have identified over 100 loci for the most common form, primary open-angle glaucoma. Two key glaucoma-associated traits also show high heritability: intraocular pressure and optic nerve head excavation damage quantified as the vertical cup-to-disc ratio. Here, since much of glaucoma heritability remains unexplained, we conducted a large-scale multitrait genome-wide association study in participants of European ancestry combining primary open-angle glaucoma and its two associated traits (total sample size over 600,000) to substantially improve genetic discovery power (263 loci). We further increased our power by then employing a multiancestry approach, which increased the number of independent risk loci to 312, with the vast majority replicating in a large independent cohort from 23andMe, Inc. (total sample size over 2.8 million; 296 loci replicated at P < 0.05, 240 after Bonferroni correction). Leveraging multiomics datasets, we identified many potential druggable genes, including neuro-protection targets likely to act via the optic nerve, a key advance for glaucoma because all existing drugs only target intraocular pressure. We further used Mendelian randomization and genetic correlation-based approaches to identify novel links to other complex traits, including immune-related diseases such as multiple sclerosis and systemic lupus erythematosus.

Autophagy disruption reduces mTORC1 activation leading to retinal ganglion cell neurodegeneration associated with glaucoma

Autophagy dysfunction has been associated with several neurodegenerative diseases including glaucoma, characterized by the degeneration of retinal ganglion cells (RGCs). However, the mechanisms by which autophagy dysfunction promotes RGC damage remain unclear. Here, we hypothesized that perturbation of the autophagy pathway results in increased autophagic demand, thereby downregulating signaling through mammalian target of rapamycin complex 1 (mTORC1), a negative regulator of autophagy, contributing to the degeneration of RGCs. We identified an impairment of autophagic-lysosomal degradation and decreased mTORC1 signaling via activation of the stress sensor adenosine monophosphate-activated protein kinase (AMPK), along with subsequent neurodegeneration in RGCs differentiated from human pluripotent stem cells (hPSCs) with a glaucoma-associated variant of Optineurin (OPTN-E50K). Similarly, the microbead occlusion model of glaucoma resulting in ocular hypertension also exhibited autophagy disruption and mTORC1 downregulation. Pharmacological inhibition of mTORC1 in hPSC-derived RGCs recapitulated disease-related neurodegenerative phenotypes in otherwise healthy RGCs, while the mTOR-independent induction of autophagy reduced protein accumulation and restored neurite outgrowth in diseased OPTN-E50K RGCs. Taken together, these results highlight an important balance between autophagy and mTORC1 signaling essential for RGC homeostasis, while disruption to these pathways contributes to neurodegenerative features in glaucoma, providing a potential therapeutic target to prevent neurodegeneration.

Genetic variants associated with glaucomatous visual field loss in primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is characterized by a progressive optic neuropathy with visual field loss. To investigate the genetic variants associated with visual field loss in POAG, Japanese POAG patients (n = 426) and control subjects (n = 246) were genotyped for 22 genetic variants predisposing to POAG that can be classified into those associated with intraocular pressure (IOP) elevation (IOP-related genetic variants) and optic nerve vulnerability independent of IOP (optic nerve-related genetic variants). The genetic risk score (GRS) of the 17 IOP-related and five optic nerve-related genetic variants was calculated, and the associations between the GRS and the mean deviation (MD) of automated static perimetry as an indicator of the severity of visual field loss and pattern standard deviation (PSD) as an indicator of the focal disturbance were evaluated. There was a significant association (Beta = - 0.51, P = 0.0012) between the IOP-related GRS and MD. The severity of visual field loss may depend on the magnitude of IOP elevation induced by additive effects of IOP-related genetic variants. A significant association (n = 135, Beta = 0.65, P = 0.0097) was found between the optic nerve-related, but not IOP-related, GRS and PSD. The optic nerve-related (optic nerve vulnerability) and IOP-related (IOP elevation) genetic variants may play an important role in the focal and diffuse visual field loss respectively. To our knowledge, this is the first report to show an association between additive effects of genetic variants predisposing to POAG and glaucomatous visual field loss, including severity and focal/diffuse disturbance of visual field loss, in POAG.

METTL23 mutation alters histone H3R17 methylation in normal-tension glaucoma

Normal-tension glaucoma (NTG) is a heterogeneous disease characterized by retinal ganglion cell (RGC) death leading to cupping of the optic nerve head and visual field loss at normal intraocular pressure (IOP). The pathogenesis of NTG remains unclear. Here, we describe a single nucleotide mutation in exon 2 of the methyltransferase-like 23 (METTL23) gene identified in 3 generations of a Japanese family with NTG. This mutation caused METTL23 mRNA aberrant splicing, which abolished normal protein production and altered subcellular localization. Mettl23-knock-in (Mettl23+/G and Mettl23G/G) and -knockout (Mettl23+/- and Mettl23-/-) mice developed a glaucoma phenotype without elevated IOP. METTL23 is a histone arginine methyltransferase expressed in murine and macaque RGCs. However, the novel mutation reduced METTL23 expression in RGCs of Mettl23G/G mice, which recapitulated both clinical and biological phenotypes. Moreover, our findings demonstrated that METTL23 catalyzed the dimethylation of H3R17 in the retina and was required for the transcription of pS2, an estrogen receptor α target gene that was critical for RGC homeostasis through the negative regulation of NF-κB-mediated TNF-α and IL-1β feedback. These findings suggest an etiologic role of METTL23 in NTG with tissue-specific pathology.

Restoration of mitochondria axonal transport by adaptor Disc1 supplementation prevents neurodegeneration and rescues visual function

Deficits in mitochondrial transport are a common feature of neurodegenerative diseases. We investigated whether loss of components of the mitochondrial transport machinery impinge directly on metabolic stress, neuronal death, and circuit dysfunction. Using multiphoton microscope live imaging, we showed that ocular hypertension, a major risk factor in glaucoma, disrupts mitochondria anterograde axonal transport leading to energy decline in vulnerable neurons. Gene- and protein-expression analysis revealed loss of the adaptor disrupted in schizophrenia 1 (Disc1) in retinal neurons subjected to high intraocular pressure. Disc1 gene delivery was sufficient to rescue anterograde transport and replenish axonal mitochondria. A genetically encoded ATP sensor combined with longitudinal live imaging showed that Disc1 supplementation increased ATP production in stressed neurons. Disc1 gene therapy promotes neuronal survival, reverses abnormal single-cell calcium dynamics, and restores visual responses. Our study demonstrates that enhancing anterograde mitochondrial transport is an effective strategy to alleviate metabolic stress and neurodegeneration.

The relationship between choroidal blood flow and glaucoma progression in a Japanese study population

PURPOSE

To determine whether choroidal blood flow (BF) is related to visual field (VF) defect severity and progression in eyes with open-angle glaucoma (OAG).

STUDY DESIGN

Retrospective and longitudinal.

METHODS

This study comprised 443 eyes of 285 OAG patients who underwent laser speckle flowgraphy (LSFG), optical coherence tomography, and visual-field (VF) testing at baseline. The patients were then observed for at least 2 years and at least 5 reliable VF tests were performed. In the LSFG images, we set regions of interest at the optic nerve head (ONH) and the parapapillary choroid to obtain ONH-tissue mean blur rate (MBR) and choroidal MBR, respectively. We used univariable and multivariable linear mixed-effects models to determine clinical factors associated with choroidal MBR at baseline. We also used a linear mixed-effects model to determine the contribution of ONH-tissue MBR and choroidal MBR to baseline mean deviation (MD) and to MD slope during follow-up, adjusting for potential confounding factors, including circumpapillary retinal nerve fiber layer thickness.

RESULTS

Choroidal MBR was associated with age, MD slope, and ONH-tissue MBR (β = -0.181, P = 0.001; β = 0.134, P = 0.002; β = 0.096, P = 0.049, respectively). ONH-tissue MBR was associated with both MD and MD slope (β = 0.146, P = 0.004; β = 0.152, P = 0.009, respectively), whereas choroidal MBR was associated only with MD slope (β = 0.147, P = 0.005).

CONCLUSION

LSFG-derived choroidal MBR might be a useful biomarker to predict VF defect progression in a Japanese population.

CHOP deletion and anti-neuroinflammation treatment with hesperidin synergistically attenuate NMDA retinal injury in mice

Glaucoma is a leading cause of blindness worldwide and is characterized by degeneration associated with the death of retinal ganglion cells (RGCs). It is believed that glaucoma is a group of heterogeneous diseases with multifactorial pathomechanisms. Here, we investigate whether anti-inflammation treatment with an ER stress blockade can selectively promote neuroprotection against NMDA injury in the RGCs. Retinal excitotoxicity was induced with an intravitreal NMDA injection. Microglial activation and neuroinflammation were evaluated with Iba1 immunostaining and cytokine gene expression. A stable HT22 cell line transfected with an NF-kB reporter was used to assess NF-kB activity after hesperidin treatment. CHOP-deficient mice were used as a model of ER stress blockade. Retinal cell death was evaluated with a TUNEL assay. As results, in the NMDA injury group, Iba1-positive microglia increased 6 h after NMDA injection. Also at 6 h, pro-inflammatory cytokines and chemokine increased, including TNFα, IL-1b, IL-6 and MCP-1. In addition, the MCP-1 promoter-driven EGFP signal, which we previously identified as a stress signal in injured RGCs, also increased; hesperidin treatment suppressed this inflammatory response and reduced stressed RGCs. In CHOP-deficient mice that received an NMDA injection, the gene expression of pro-inflammatory cytokines, chemokines, markers of active microglia, and inflammatory regulators was greater than in WT mice. In WT mice, hesperidin treatment partially prevented retinal cell death after NMDA injury; this neuroprotective effect was enhanced in CHOP-deficient mice. These findings demonstrate that ER stress blockade is not enough by itself to prevent RGC loss due to neuroinflammation in the retina, but it has a synergistic neuroprotective effect after NMDA injury when combined with an anti-inflammatory treatment based on hesperidin.

The Effect of Dietary Antioxidant Supplementation in Patients with Glaucoma

Purpose

Oxidative stress may be a risk factor for glaucoma, and many previous reports have suggested that antioxidants could be a promising treatment. Here, we investigated the effects of a novel supplement containing three food-derived antioxidants (hesperidin, crocetin, and Tamarindus indica) on markers of oxidative stress in patients with glaucoma.

Patients and Methods

This study had a prospective, single arm design. Thirty Japanese glaucoma patients were recruited and given 4 tablets with ample water twice a day for 8 weeks. The treatment was stopped, and the subjects were followed for an additional 8 weeks. We measured biological antioxidant potential (BAP) with a free radical analyzer. We also measured urinary 8-hydroxy-2ʹ-deoxyguanosine (8-OHdG; a marker of oxidative DNA damage). Clinical laboratory data were measured in venous blood samples. Clinical parameters were also recorded. Comparisons used a one-way analysis of variance (ANOVA) followed by Dunnett’s test.

Results

The 8-OHdG level was not reduced. We also divided the patients into groups with high or low oxidative stress. In patients with relatively high oxidative stress, the 8-OHdG level was significantly reduced at weeks 4, 8, 12, and 16 (P < 0.001, P < 0.01, P < 0.01, P < 0.01), and BAP was significantly elevated at weeks 8 and 12 (P = 0.03, P = 0.04). In patients with relatively low oxidative stress, the 8-OHdG level was not significantly reduced during supplement intake but was significantly elevated at weeks 12 and 16 (P =0.03, P = 0.04), while BAP was not significantly elevated.

Conclusion

An 8-week oral course of antioxidant supplementation was effective in patients with a high oxidative stress level. Dietary supplementation could hold promise in the treatment of systemic oxidative stress-related diseases.

Genome-wide meta-analysis identifies 127 open-angle glaucoma loci with consistent effect across ancestries

Primary open-angle glaucoma (POAG), is a heritable common cause of blindness world-wide. To identify risk loci, we conduct a large multi-ethnic meta-analysis of genome-wide association studies on a total of 34,179 cases and 349,321 controls, identifying 44 previously unreported risk loci and confirming 83 loci that were previously known. The majority of loci have broadly consistent effects across European, Asian and African ancestries. Cross-ancestry data improve fine-mapping of causal variants for several loci. Integration of multiple lines of genetic evidence support the functional relevance of the identified POAG risk loci and highlight potential contributions of several genes to POAG pathogenesis, including SVEP1, RERE, VCAM1, ZNF638, CLIC5, SLC2A12, YAP1, MXRA5, and SMAD6. Several drug compounds targeting POAG risk genes may be potential glaucoma therapeutic candidates.

Time-Course Changes in Optic Nerve Head Blood Flow and Retinal Nerve Fiber Layer Thickness in Eyes with Open-angle Glaucoma

PURPOSE

To determine whether decreased optic nerve head (ONH) blood flow (BF) precedes or follows decreased circumpapillary retinal nerve fiber layer thickness (cpRNFLT) in eyes with open-angle glaucoma (OAG).

DESIGN

Retrospective, longitudinal study.

PARTICIPANTS

This study followed up 350 eyes of 225 OAG patients for at least 2 years and collected data from each patient from at least 5 examinations obtained with laser speckle flowgraphy (LSFG) and OCT.

METHODS

In the superior, temporal, and inferior ONH quadrants, tissue area mean blur rate (MT), representing ONH tissue BF, was measured with LSFG, whereas cpRNFLT was measured with OCT. A multivariate linear mixed-effects model was used to identify potential predictors of faster MT decrease, adjusting for possible confounding factors. Based on these results, each quadrant of each patient was assigned a risk point if the quadrant was the superior or temporal, if patient age was older than the median (61 years), and if patient pulse rate was higher than median (74 beats per minute). The quadrants were then compared with a mixed-effects Cox model for MT and cpRNFLT changes, defined as a difference between the baseline value and the values from the latest 2 consecutive follow-up visits of more than 1.96 × the corresponding coefficient of variation.

MAIN OUTCOME MEASURES

Ophthalmic and systemic variables and MT and cpRNFLT in the superior, temporal, and inferior quadrants.

RESULTS

The multivariate model showed that MT decrease was faster in older patients with higher pulse rate and slower in inferior quadrants (P < 0.05). Quadrants with 0 risk points showed primary cpRNFLT decrease (P = 0.048), 1-risk point quadrants showed simultaneous cpRNFLT and MT decrease (P = 0.260), and 2-risk point and 3-risk point quadrants showed primary MT decrease (P < 0.001).

CONCLUSIONS

Older patients with higher pulse rate are at greater risk of a primary reduction in ONH tissue BF, that is, preceding cpRNFLT decrease, in the superior and temporal quadrants.

Serum anti-recoverin antibodies is found in elderly patients with retinitis pigmentosa and cancer

PURPOSE

To screen for anti-recoverin antibodies in elderly patients with retinitis pigmentosa (RP) with or without cancer and cross-sectionally characterize the seropositive patients clinically.

METHODS

Serum from 75 RP patients who had been tested for mutations in a panel of 83 RP genes and 73 normal controls, all aged 50-80 years, were screened for anti-recoverin antibodies by Western blot using recombinant recoverin, retinal lysate from a marmoset and commercial anti-recoverin antibodies as a control.

RESULTS

Three RP patients with typical pigmentary degeneration of the 75 (4.0%) were seropositive for anti-recoverin antibody. Pathogenic mutations were identified in two seropositive RP patients. All three patients had visual impairment since childhood and were diagnosed as RP by the age of 30. The severity of the retinopathy varied greatly among these three patients, ranging in visual acuity from light perception OU to 20/30 OU. Retinitis pigmentosa (RP) patients with a history of cancer were more likely to have anti-recoverin antibodies (3/14; 21.4%) than those without (0/61; 0%; p = 0.005, Fischer exact test). All 73 healthy controls with no history of cancer were also seronegative.

CONCLUSION

Our results show that serum anti-recoverin antibodies can be detected in typical RP patients with identified pathogenic mutations and that a history of cancer may increase the risk of developing anti-recoverin antibodies.

The optic nerve head vasoreactive response to systemic hyperoxia and visual field defect progression in open-angle glaucoma, a pilot study

PURPOSE

To investigate the effect of optic nerve head (ONH) tissue vasoreactivity on glaucoma visual field defect progression.

METHODS

This prospective, longitudinal study comprised 28 eyes of 16 patients with open-angle glaucoma. Baseline data were obtained from oxygen inhalation testing, including laser speckle flowgraphy measurements of tissue-area mean blur rate (MT), which represents ONH tissue blood flow, and the mean percentage change in MT (MT-change). Follow-up data were collected for at least 2 years, including at least 5 reliable visual field tests. The average total deviation (TD) was calculated in each sector of the Garway-Heath map; in this study, superior, central and inferior TD corresponded to inferior, temporal and superior MT or MT-change, respectively. MT and MT-change in three sectors per eye were included as explanatory variables in a multivariable linear mixed-effects model, with TD slope set as the response variable.

RESULTS

At baseline, lower MT and higher diastolic blood pressure were associated with lower MT-change (p < 0.05). Additionally, MT-change significantly contributed to TD slope in the corresponding sectors (β = 0.41, p = 0.01).

CONCLUSIONS

Weaker ONH tissue vasoreactivity to systemic hyperoxia, assessed with laser speckle flowgraphy, was associated with lower baseline ONH tissue blood flow, higher diastolic blood pressure and rapid visual field defect progression. Laser speckle flowgraphy variables during oxygen provocation testing may represent potentially useful predictive biomarkers of glaucoma progression.

Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei

Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250  MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.

Serum immunoglobulin G antibody titer to Fusobacterium nucleatum is associated with unfavorable outcome after stroke

Stroke can be a cause of death, while in non-fatal cases it is a common cause of various disabilities resulting from associated brain damage. However, whether a specific periodontal pathogen is associated with increased risk of unfavorable outcome after stroke remains unknown. We examined risk factors for unfavorable outcome following stroke occurrence, including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset (favorable = score 0 or 1; unfavorable = score 2-6). The associations of risk factors with unfavorable outcome, including serum titers of IgG antibodies to 16 periodontal pathogens, were examined. Logistic regression analysis showed that the initial National Institutes of Health stroke scale score [odds ratio (OR) = 1·24, 95% confidence interval (CI) = 1·18-1·31, P < 0·001] and C-reactive protein (OR = 1·29, 95% CI = 1·10-1·51, P = 0·002) were independently associated with unfavorable outcome after stroke. Following adjustment with those, detection of the antibody for Fusobacterium nucleatum ATCC 10953 in serum remained an independent predictor of unfavorable outcome (OR = 3·12, 95% CI = 1·55-6·29, P = 0·002). Determination of the antibody titer to F. nucleatum ATCC 10953 in serum may be useful as a predictor of unfavorable outcome after stroke.

A pyruvate dehydrogenase kinase inhibitor prevents retinal cell death and improves energy metabolism in rat retinas after ischemia/reperfusion injury

We aimed to assess the neuroprotective effect of a pyruvate dehydrogenase kinase (PDK) inhibitor, Nov3r after ischemia/reperfusion (IR) injury in rats. IR injury was induced by applying 150 mmHg of intraocular pressure for 50 min. Nov3r was orally administered (100 mg/kg) 3 h before and 24 h after IR injury. TUNEL-positive cells increased and immunoreactive RBPMS-positive cells decreased in the rat retinas after IR injury. Administration of Nov3r significantly ameliorated the increase in TUNEL-positive cells and prevented the RBPMS-positive cell decrease. Similarly, the number of IR-induced Iba1-positive microglial cells was significantly reduced with Nov3r treatment. Among metabolic parameters, IR damage induced the elevation of lactate and pyruvate, and the reduction of ATP. Oral administration of Nov3r ameliorated these changes. Our data suggest that the Nov3r had a retinal neuroprotective effect in IR injury in rats. This finding suggests that the regulation of pyruvate dehydrogenase (PDH) activity has potential therapeutic value by enabling metabolic reprograming in diseases associated with ischemic retinal damage, such as diabetic retinopathy, retinopathy of prematurity, retinal vein occlusion, ischemic optic neuropathy and glaucoma.

Structural Characterization of Glaucoma Patients with Low Ocular Blood Flow

Purpose: There is an unclear relationship between ocular blood flow (OBF) and the structural characteristics of the optic nerve head (ONH) in glaucoma, a multifactorial disease. This study used laser speckle flowgraphy (LSFG) to identify low-OBF glaucoma patients and investigated the ONH in these patients. Materials and Methods: In 533 eyes with glaucoma, we determined confounding factors for LSFG-measured OBF (tissue-area mean blur rate: MT) and corrected MT with a linear mixed-effects model (LMM). Structural ONH data (from fundus stereo photography), OCT data, and clinical characteristics were then compared in patients with corrected MT in the upper and lower quartiles using the LMM. Results: Single regression showed significant correlations between MT and age, spherical equivalent (SE), central corneal thickness (CCT), and a weighted count of retinal ganglion cells (wRGC), but not axial length or systemic blood pressure. Gender also significantly influenced MT; MT was corrected for these correlated factors and also glaucoma type with the LMM. The lower-quartile MT group had a significantly larger cup area and cup-disc area ratio and lower temporal quadrant circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and macular ganglion cell complex (GCC) than the upper-quartile group. Conclusions: Low-OBF glaucoma patients were characterized by a larger cup-disc ratio, and higher susceptibility to damage in the temporal disc and the macular area.

The association between oxidative stress and corneal hysteresis in patients with glaucoma

Systemic antioxidative status has been implicated in glaucoma pathogenesis. Additionally, corneal hysteresis (CH) may contribute to glaucoma progression. Here, we evaluated the relationship between biological antioxidant potential (BAP) and CH. This study included 103 patients with open-angle glaucoma (OAG). We used a free radical analyzer to measure BAP, and an ocular response analyzer to measure CH and corneal resistance factor (CRF). We evaluated the relationship between systemic oxidative stress and other clinical parameters with Spearman's rank correlation test and a multi-regression analysis. BAP was not correlated to either CH or CRF in the male or female OAG patients. BAP was correlated to both CH and CRF in the female OAG patients older than 57 years (r = 0.51, P = 0.003; r = 0.49, P = 0.004), but uncorrelated in the female OAG patients younger than 57 years. Multiple regression analysis revealed that BAP independently contributed to CH (P = 0.025) and CRF (P = 0.015) in the older female OAG patients. Systemic oxidative stress may significantly affect the viscoelasticity of the cornea in older female OAG patients. Future studies are needed to confirm that low systemic antioxidative status and low corneal hysteresis contribute to glaucoma pathogenesis.

Fragmentation of Single-Particle Strength around the Doubly Magic Nucleus ^{132}Sn and the Position of the 0f_{5/2} Proton-Hole State in ^{131}In

Spectroscopic factors of neutron-hole and proton-hole states in ^{131}Sn and ^{131}In, respectively, were measured using one-nucleon removal reactions from doubly magic ^{132}Sn at relativistic energies. For ^{131}In, a 2910(50)-keV γ ray was observed for the first time and tentatively assigned to a decay from a 5/2^{-} state at 3275(50) keV to the known 1/2^{-} level at 365 keV. The spectroscopic factors determined for this new excited state and three other single-hole states provide first evidence for a strong fragmentation of single-hole strength in ^{131}Sn and ^{131}In. The experimental results are compared to theoretical calculations based on the relativistic particle-vibration coupling model and to experimental information for single-hole states in the stable doubly magic nucleus ^{208}Pb.

Exploring the Novel Susceptibility Gene Variants for Primary Open-Angle Glaucoma in East Asian Cohorts: The GLAU-GENDISK Study

Primary open-angle glaucoma (POAG) can develop even within normal ranges of intraocular pressure, and this type of glaucoma (so-called ‘normal-tension glaucoma [NTG]’) is highly prevalent in East Asia including Korea and Japan. We conducted exome chip analysis to identify low-frequency and rare variants associated with POAG from the primary cohort (309 POAG patients and 5,400 control, all Koreans). For replication, Korean (310 POAG patients and 5,612 controls) and Japanese (565 POAG patients and 1,104 controls) cohorts were further investigated by targeted genotyping. SNP rs116121322 in LRRC27 showed nominally significant association with POAG in the discovery cohort (OR = 29.85, P = 2E–06). This SNP was validated in the Korean replication cohort but only in the NTG subgroups (OR = 9.86, P = 0.007). Japanese replication cohort did not show significant association with POAG (P .00.44). However, the meta-analysis in the entire cohort revealed significant association of rs116121322 with POAG (OR_combined = 10.28, P_combined = 1.4E–07). The LRRC27 protein expression was confirmed from human trabecular meshwork cells. For gene-based testing, METTL20 showed a significant association in POAG (P_combined = 0.002) and in the subgroup of NTG (P_combined = 0.02), whereas ZNF677 were significantly associated with only in the subgroup of high-tension glaucoma (P_combined = 1.5E–06). Our findings may provide further genetic backgrounds into the pathogenesis of POAG, especially for the patients who have lower baseline intraocular pressures.

Cross-section measurement in the reactions of 136Xe on proton, deuteron and carbon

The isotopic production cross sections for the reactions of 136Xe induced by proton, deuteron and carbon at 168 MeV/u were obtained by using the inverse kinematics technique at RIKEN Radioactive Isotope Beam Factory. The target dependence of the cross sections was investigated systematically. It was found that for the light-mass products, the cross sections on carbon are larger than those on deuteron and proton. The measured cross sections on proton were compared with the previous data at higher reaction energies to study the energy dependence. The experimental results were compared with the theoretical calculations including both the intranuclear cascade and evaporation processes using PHITS and with the EPAX and SPACS empirical parameterizations.

The relationship between glutathione levels in leukocytes and ocular clinical parameters in glaucoma

PURPOSE

To investigate the effect of mitochondrial dysfunction on the autoregulation of blood flow, by measuring levels of glutathione, an indicator of mitochondrial dysfunction, in glaucoma patients.

METHODS

Fifty-six OAG patients and 21 age-matched controls underwent a blood assay. Mitochondrial function was measured according to the levels of total glutathione (t-GSH), reduced GSH (GSH), and oxidized GSH (GSSG, glutathione disulfide) in peripheral blood mononuclear cells. Ocular blood flow in the optic nerve head was assessed with laser speckle flowgraphy parameters, including acceleration time index (ATI). We determined correlations between these measurements and other clinical parameters. Furthermore, we investigated the association between glutathione levels and glaucoma with a logistic regression analysis. Finally, we calculated the area under the receiver operating characteristic (ROC) curve in order to determine the power of redox index (the log GSH/GSSG ratio) to distinguish the groups.

RESULTS

OAG patients demonstrated significantly higher GSSG levels and a lower redox index than the controls (p = 0.01, p = 0.01, respectively), but total GSH and reduced GSH levels were similar in the OAG subjects and controls (p = 0.80, p = 0.94, respectively). Additionally, redox index was significantly correlated with mean deviation (MD) of the visual field (r = 0.29, p = 0.03) and ATI (r = -0.30, p = 0.03). Multiple linear regression analysis showed that redox index contributed to MD (p = 0.02) and ATI (p = 0.04). The receiver operating characteristic curve (AUC) analysis suggested that redox index could differentiate between control eyes and eyes with glaucoma (AUC; 0.70: 95% interval; 0.57-0.84). The cutoff point for redox index to maximize its sensitivity and specificity was 2.0 (sensitivity: 91.1%, specificity: 42.9%).

CONCLUSIONS

These results suggest that redox index is lower in OAG patients than in controls. Thus, it is possible that mitochondrial dysfunction contributes to glaucoma pathogenesis by causing vascular alterations.

The DNA topoisomerase II inhibitor amsacrine as a novel candidate adjuvant in a model of glaucoma filtration surgery

Treatments for refractory glaucoma include trabeculectomy, in which a filtering bleb is created to reduce aqueous pressure. Mitomycin C (MMC) is often used as an adjuvant to reduce post-trabeculectomy bleb scarring and consequent failure. However, scarring sometimes still occurs. Thus, we searched for more effective trabeculectomy adjuvants with high-throughput screening (HTS) of a library of 1,165 off-patent drug compounds. This revealed that amsacrine (AMSA), a DNA topoisomerase II (TOP2) inhibitor, was the top candidate. Compared to MMC, rabbits that underwent trabeculectomy with 10% AMSA had lower IOP at 42, 56, and 70 days (P < 0.01 at all measurement points) and a higher bleb score at 28, 42, 56, and 70 days (P =  < 0.01, 0.04, 0.04, and < 0.01, respectively). Compared to saline, rabbits that received 1% AMSA also had lower IOP and better bleb score at all time points, without a sharp drop in IOP just after surgery (all P < 0.01). Both effects were milder than MMC at 7 days (P = 0.02 and <0.01, respectively). Thus, this study showed that HTS may help identify new, promising uses for off-patent drugs. Furthermore, trabeculectomy with AMSA at a suitable concentration may improve the prognosis after trabeculectomy compared to MMC.

Quantitative analysis of the macula with optical coherence tomography angiography in normal Japanese subjects: The Taiwa Study

This study evaluated age-related changes in the superficial and deep retinal capillary plexus (SCP and DCP, respectively) and in the foveal avascular zone (FAZ). SCP and DCP perfusion density (PD) were measured in optical coherence tomography angiography (OCTA) macular scans of 145 eyes of 145 healthy Japanese subjects, and findings were compared with SCP FAZ and clinical data. We found that age was negatively correlated with SCP and DCP PD (r = -0.17, P = 0.04 and r = -0.20, P = 0.02, respectively) and positively correlated with FAZ area (r = 0.18, P = 0.03). SCP and DCP PD were correlated with each other (r = 0.67, P < 0.001). FAZ area was negatively correlated with SCP PD, DCP PD and central macular thickness (CMT) (r = -0.18, P = 0.03; r = -0.25, P < 0.01; and r = -0.39, P < 0.001, respectively). FAZ was larger and CMT was lower (P = 0.01 and P < 0.001, respectively) in women than men. SCP and DCP PD were positively correlated with estimated glomerular filtration rate (r = 0.17, P = 0.03 and r = 0.24, P < 0.01, respectively). Multiple regression analysis confirmed that age independently affected DCP PD and FAZ (P = 0.02 and P < 0.01, respectively) and that CMT independently affected FAZ area (P < 0.001). Thus, normal subjects showed age-related decreases in macular PD and renal function. FAZ and CMT were related, suggesting that age-related changes in macular thickness also affect capillary vasculature.

Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250  MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

The Impact of Intraocular Pressure Elevation on Optic Nerve Head and Choroidal Blood Flow

Purpose

To use laser speckle flowgraphy (LSFG) to assess blood flow (BF) in the optic nerve head (ONH) tissue and choroid during elevated intraocular pressure (IOP).

Methods

This prospective study included 20 eyes of 20 healthy volunteers. The testing protocol had a baseline phase, two elevated IOP phases (+10 and +20 mm Hg), and a recovery phase. IOP was elevated by pushing against the eyelid with a novel tubular device attached to the LSFG apparatus. Measurement parameters in each phase included: LSFG-derived mean blur rate (MBR) and flow acceleration index (FAI); systemic parameters, and IOP. The % change against baseline was calculated for each phase. The protocol was repeated five times to calculate the coefficient of variation (CV) for % change MBR and to determine the effect of mydriasis on % change MBR. We compared % change MBR and FAI and evaluated the relationship between % change ocular perfusion pressure (OPP) and MBR in the choroid and ONH tissue.

Results

The % change MBR was highly reproducible (CV: 6.1-8.7%) and not affected by mydriasis (P = 0.57-0.96). The % change MBR and FAI were higher in the ONH tissue than choroid during IOP elevation (P = 0.04). The % change OPP and MBR showed positive linear correlations and two-segmental linear correlations in the choroid and ONH tissue, respectively (P < 0.01).

Conclusion

Hemodynamics during IOP elevation differ in the choroid and ONH tissue. LSFG enables highly reproducible assessment of the dynamic autoregulation of ocular BF in the ONH tissue.

Glaucoma Diagnosis with Machine Learning Based on Optical Coherence Tomography and Color Fundus Images

This study aimed to develop a machine learning-based algorithm for glaucoma diagnosis in patients with open-angle glaucoma, based on three-dimensional optical coherence tomography (OCT) data and color fundus images. In this study, 208 glaucomatous and 149 healthy eyes were enrolled, and color fundus images and volumetric OCT data from the optic disc and macular area of these eyes were captured with a spectral-domain OCT (3D OCT-2000, Topcon). Thickness and deviation maps were created with a segmentation algorithm. Transfer learning of convolutional neural network (CNN) was used with the following types of input images: (1) fundus image of optic disc in grayscale format, (2) disc retinal nerve fiber layer (RNFL) thickness map, (3) macular ganglion cell complex (GCC) thickness map, (4) disc RNFL deviation map, and (5) macular GCC deviation map. Data augmentation and dropout were performed to train the CNN. For combining the results from each CNN model, a random forest (RF) was trained to classify the disc fundus images of healthy and glaucomatous eyes using feature vector representation of each input image, removing the second fully connected layer. The area under receiver operating characteristic curve (AUC) of a 10-fold cross validation (CV) was used to evaluate the models. The 10-fold CV AUCs of the CNNs were 0.940 for color fundus images, 0.942 for RNFL thickness maps, 0.944 for macular GCC thickness maps, 0.949 for disc RNFL deviation maps, and 0.952 for macular GCC deviation maps. The RF combining the five separate CNN models improved the 10-fold CV AUC to 0.963. Therefore, the machine learning system described here can accurately differentiate between healthy and glaucomatous subjects based on their extracted images from OCT data and color fundus images. This system should help to improve the diagnostic accuracy in glaucoma.

Pilot study for three-dimensional assessment of laminar pore structure in patients with glaucoma, as measured with swept source optical coherence tomography

Purpose

To develop a method to quantify, based on swept-source optical coherence tomography (OCT), the 3D structure of the laminar pores in patients with glaucoma.

Methods

This retrospective study examined 160 laminar pores from 8 eyes of 8 cases: 4 normal subjects and 4 open-angle glaucoma (OAG) patients. We reconstructed 3D volume data for a 3 x 3 mm disc, using a method similar to OCT angiography, and segmented the structure of the lamina cribrosa. Then, we manually segmented each laminar pore in sequential C-scan images (>90 slices at 2.6-micron intervals) with VCAT5 (RIKEN, Japan). We compared the control and OAG subjects with the Mann-Whitney U test. Differences were considered significant at p < 0.05.

Results

We found that the laminar pores of the OAG patients had a significantly smaller average cross-sectional area, smaller 3D volume (adjusted to the average thickness of the lamina cribrosa), and higher true sphericity, and lower principal value (P1, 2, 3) of the 3D structure data (all: p < 0.0001). The topographic distribution of damaged laminar pores was consistent with the damaged area of the macular map.

Conclusion

We successfully developed a method to quantify the 3D structure of the laminar pores; providing a useful tool to assess lamina cribrosa-associated risk factors for glaucoma. These findings promise to benefit future investigations into the pathomechanisms of glaucoma.

Association between mitochondrial DNA damage and ocular blood flow in patients with glaucoma

Background/Aims

We determined the relationship between tissue mean blur rate (MT) and mitochondrial dysfunction, represented by the mitochondrial/nuclear DNA (mtDNA/nDNA) ratio. We also investigated the usefulness of these biomarkers.

Methods

We assessed ocular blood flow in 123 eyes of 123 patients with open-angle glaucoma (OAG) and 37 control eyes of 37 healthy subjects by measuring MT in the optic nerve head with laser speckle flowgraphy. We measured mtDNA and nDNA with PCR, calculated the mtDNA/nDNA ratio and compared this ratio with MT using Spearman’s rank test. We used multiple regression analysis to further investigate the association between MT and glaucoma in the most severe group.

Results

The control and the patients with glaucoma had significant differences in the mtDNA/nDNA ratio, circumpapillary retinal nerve fibre layer thickness and MT. There was no significant relationship between the mtDNA/nDNA ratio and MT in patients with OAG overall or the female patients with OAG, but there was a significant relationship between the mtDNA/nDNA ratio and MT, temporal-MT and superior-MT in male patients with severe OAG (r=−0.46, p=0.03; r=−0.51, p=0.02; r=−0.61, p<0.01, respectively). Furthermore, we found that the mtDNA/nDNA ratio was an independent contributor to temporal-MT and superior-MT in these patients (p<0.01 and p=0.03, respectively).

Conclusion

We found that there was a significant relationship between the mtDNA/nDNA ratio and MT in male patients with severe OAG, suggesting that the mtDNA/nDNA ratio may be a new biomarker in glaucoma and may help research on the vulnerability of these patients to mitochondrial dysfunction.

Erratum: Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu [Phys. Rev. Lett. 119, 192501 (2017)]

This corrects the article DOI: 10.1103/PhysRevLett.119.192501.

Metabolomic changes in the mouse retina after optic nerve injury

In glaucoma, although axonal injury drives retinal ganglion cell (RGC) death, little is known about the underlying pathomechanisms. To provide new mechanistic insights and identify new biomarkers, we combined latest non-targeting metabolomics analyses to profile altered metabolites in the mouse whole retina 2, 4, and 7 days after optic nerve crush (NC). Ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry and liquid chromatography Fourier transform mass spectrometry covering wide spectrum of metabolites in combination highlighted 30 metabolites that changed its concentration after NC. The analysis displayed similar changes for purine nucleotide and glutathione as reported previously in another animal model of axonal injury and detected multiple metabolites that increased after the injury. After studying the specificity of the identified metabolites to RGCs in histological sections using imaging mass spectrometry, two metabolites, i.e., L-acetylcarnitine and phosphatidylcholine were increased not only preceding the peak of RGC death in the whole retina but also at the RGC layer (2.3-fold and 1.2-fold, respectively). These phospholipids propose novel mechanisms of RGC death and may serve as early biomarkers of axonal injury. The combinatory metabolomics analyses promise to illuminate pathomechanisms, reveal biomarkers, and allow the discovery of new therapeutic targets of glaucoma.

Ecel1 Knockdown With an AAV2-Mediated CRISPR/Cas9 System Promotes Optic Nerve Damage-Induced RGC Death in the Mouse Retina

Purpose

To assess the therapeutic potential of endothelin-converting enzyme-like 1 (Ecel1) in a mouse model of optic nerve crush.

Methods

Ecel1 expression was evaluated with real time quantitative (qRT)-PCR, Western blotting, and immunohistochemistry in mouse retinas after optic nerve crush. Vinblastine administration to the optic nerve and the intravitreal injection of N-methyl-d-aspartate (NMDA) were used to assess Ecel1 gene expression. Ecel1 was deleted with an adeno-associated viral (AAV) clustered regulatory interspaced short palindromic repeat (CRISPR)/Cas9 system, and retinal ganglion cell (RGC) survival was investigated with retrograde labeling, qRT-PCR, and visual evoked potential.

Results

Optic nerve crush induced Ecel1 expression specifically in the RGCs, peaking on day 4 after optic nerve crush. Ecel1 gene expression was induced by the vinblastine-induced inhibition of axonal flow, but not by NMDA-induced excitotoxicity, even though both are triggers of RGC death. Knockdown of Ecel1 promoted the loss of RGCs after optic nerve crush.

Conclusions

Our data suggest that Ecel1 induction is part of the retinal neuroprotective response to axonal injury in mice. These findings might provide insight into novel therapeutic targets for the attenuation of RGC damage, such as occurs in traumatic optic neuropathy.

Ocular microcirculation measurement with laser speckle flowgraphy and optical coherence tomography angiography in glaucoma

PURPOSE

To compare glaucoma severity with ocular microcirculation, measured with either laser speckle flowgraphy (LSFG) or optical coherence tomography angiography (OCTA).

METHODS

We retrospectively studied 82 eyes of 82 open-angle glaucoma (OAG) patients who underwent same-day LSFG and OCTA examinations, with 20 eyes of 20 healthy subjects as controls. In OCTA images, vessel density (VD) (%) was calculated in concentric regions (regions 1, 2 and 3: R1, R2 and R3, respectively) defined by 1.6-, 3.2- and 3.6-mm-diameter circles around the optic nerve head (ONH). In R3, the large vessels were automatically masked to calculate pure capillary density (auto R3 VD). LSFG-measured mean blur rate (MBR) was examined in the overall ONH (MA), vessel-area ONH (MV) and tissue-area ONH (MT).

RESULTS

Auto R3 VD had high reproducibility (coefficient of variation: 1.65-3.88%) and accurately reflected manual R3 VD [mean bias: -0.0087% (auto R3 VD - manual R3 VD)]. MA and MT decreased significantly with OAG severity, especially in the early OAG stages (control vs. mild: p = 0.003 and p < 0.001, respectively). R1 VD did not change with severity. R2 and auto R3 VD decreased significantly with OAG severity, especially in the severe stages (R2, mild vs. severe: p = 0.008; auto R3 VD, mild vs. severe: p < 0.001, moderate vs. severe: p = 0.028).

CONCLUSION

Optical coherence tomography angiography-derived auto R3 VD is novel, reproducible and accurately reflects manual measurements. It is useful for differentiating moderate and advanced glaucoma, while LSFG-derived MT is useful for identifying early glaucoma.

Factors associated with deep circulation in the peripapillary chorioretinal atrophy zone in normal-tension glaucoma with myopic disc

PURPOSE

To investigate factors associated with choroidal microcirculation in the peripapillary chorioretinal atrophy (PPA) zone in eyes with normal-tension glaucoma (NTG) and myopic disc.

METHODS

In 100 eyes of 100 NTG patients with myopic disc and 20 eyes of 20 age-matched myopic controls, 4.5 × 4.5 mm scans were made of the optic nerve head with optical coherence tomography angiography (OCTA). Peripapillary chorioretinal atrophy (PPA) area and PPA superficial choroidal image intensity (PPA-CI) were calculated with image j software. Clinical characteristics, laser speckle flowgraphy-measured mean blur rate in the temporal tissue area (temporal MT), the central thresholds (the averaged standard automated perimetry-measured visual field thresholds in the four paracentral points) and 3D-OCT-measured ganglion cell complex thickness in the papillomacular bundle (PMB-GCCT) were recorded.

RESULTS

The NTG patients had significantly lower intraocular pressure, PMB-GCCT and central threshold values, and a larger PPA area, than the controls. The area under the receiver operating characteristics curve to differentiate NTG with parafoveal scotoma (PFS) from controls was 0.76 for temporal MT, 0.85 for PPA-CI and 0.87 for PMB-GCCT. Univariate and multivariate analyses revealed that PPA-CI was negatively correlated with age, pulse rate, best-corrected visual acuity, axial length and PPA area, and positively correlated with temporal MT, PMB-GCCT and the central thresholds.

CONCLUSION

Peripapillary chorioretinal atrophy (PPA)-CI was associated with temporal MT, ageing, bradycardia, axial length elongation and changes in central retinal structure and visual function in patients with NTG and myopic disc. Thus, microcirculation deep within the PPA zone might be a clinically useful biomarker of PFS in NTG.

Genome-wide association study identifies seven novel susceptibility loci for primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide for which 15 disease-associated loci had been discovered. Among them, only 5 loci have been associated with POAG in Asians. We carried out a genome-wide association study and a replication study that included a total of 7378 POAG cases and 36 385 controls from a Japanese population. After combining the genome-wide association study and the two replication sets, we identified 11 POAG-associated loci, including 4 known (CDKN2B-AS1, ABCA1, SIX6 and AFAP1) and 7 novel loci (FNDC3B, ANKRD55-MAP3K1, LMX1B, LHPP, HMGA2, MEIS2 and LOXL1) at a genome-wide significance level (P < 5.0×10-8), bringing the total number of POAG-susceptibility loci to 22. The 7 novel variants were subsequently evaluated in a multiethnic population comprising non-Japanese East Asians (1008 cases, 591 controls), Europeans (5008 cases, 35 472 controls) and Africans (2341 cases, 2037 controls). The candidate genes located within the new loci were related to ocular development (LMX1B, HMGA2 and MAP3K1) and glaucoma-related phenotypes (FNDC3B, LMX1B and LOXL1). Pathway analysis suggested epidermal growth factor receptor signaling might be involved in POAG pathogenesis. Genetic correlation analysis revealed the relationships between POAG and systemic diseases, including type 2 diabetes and cardiovascular diseases. These results improve our understanding of the genetic factors that affect the risk of developing POAG and provide new insight into the genetic architecture of POAG in Asians.

Preperimetric Glaucoma Prospective Study (PPGPS): Predicting Visual Field Progression With Basal Optic Nerve Head Blood Flow in Normotensive PPG Eyes

Purpose

To investigate the site specificity of visual field changes in eyes with normotensive preperimetric glaucoma (PPG), and to determine factors influencing visual field progression.

Methods

This prospective study comprised 84 eyes of 84 normotensive PPG patients followed for at least 16 months. Optic nerve head (ONH) blood flow was assessed with tissue-area mean blur rate (MBR_T), derived from laser speckle flowgraphy. Total deviation (TD) was measured in each sector of the Garway-Heath map to evaluate the site specificity of visual field loss. Subjects with a TD slope in the first quartile were classified as progressive, and other subjects as nonprogressive. Linear and multiple regression analyses were performed to determine factors affecting visual field progression.

Results

TD in the superior sector significantly decreased in the subjects overall during the follow-up periods (−0.48 ± 1.92 dB/y, P = 0.025). Linear regression analysis showed that basal MBR_T-inferior was correlated significantly with TD-superior slope (r = 0.332, P = 0.002). Furthermore, basal MBR_T was significantly lower in this sector in the progressive than the nonprogressive group (P = 0.010). Multiple linear regression analysis revealed that basal MBR_T-inferior was the only predictive factor for TD-superior slope (β = 0.329, P = 0.005).

Conclusions

These findings suggest that superior-sector visual field progression is most common in normotensive PPG eyes, and that reduced basal ONH blood flow is associated with visual field progression.

Translational Relevance

These findings provide new insight into the involvement of ONH blood flow impairment in glaucoma pathogenesis, and demonstrate the importance of assessing ONH blood flow to determine visual field progression in normotensive PPG.

Genetic analysis of Japanese primary open-angle glaucoma patients and clinical characterization of risk alleles near CDKN2B-AS1, SIX6 and GAS7

PURPOSE

To test the genetic association between Japanese patients with primary open-angle glaucoma (POAG) and the previously reported POAG susceptibility loci and to perform genotype-phenotype analysis.

METHODS

Genetic associations for 27 SNPs from 16 loci previously linked to POAG were assessed using genome-wide SNP data of the primary cohort (565 Japanese POAG patients and 1,104 controls). Reproducibility of the assessment was tested in 607 POAG cases and 455 controls (second cohort) with a targeted genotyping approach. For POAG-associated variants, a genotype-phenotype correlation study (additive, dominant, recessive model) was performed using the objective clinical data derived from 598 eyes of 598 POAG patients.

RESULTS

Among 27 SNPs from 16 loci previously linked to POAG, genotypes for total of 20 SNPs in 13 loci were available for targeted association study. Among 8 SNPs in 3 loci that showed at least nominal association (P < 5.00E-02) in the primary cohort, a representative SNP for each loci (rs2157719 for CDKN2B-AS1, rs33912345 for SIX6, and rs9913911 for GAS7) were selected. For these SNPs the association was found significant in both the second cohort analysis and meta-analysis. The genotype-phenotype analysis revealed significant correlations between CDKN2B-AS1 (rs2157719) and decreased intraocular pressure (β = -6.89 mmHg, P = 1.70E-04; dominant model) after multiple corrections. In addition, nominal correlation was observed between CDKN2B-AS1 (rs2157719) and optic nerve head blood flow (β = -0.54 and -0.67 arbitrary units (AU), P = 2.00E-02 and 1.39E-02), between SIX6 (rs33912345) and decreased total peripapillary retinal nerve fiber layer thickness (β = -2.16 and -2.82 μm, P = 4.68E-02 and 2.40E-02, additive and recessive model, respectively) and increased optic nerve head blood flow (β = 0.44 AU, P = 2.20E-02; additive model) and between GAS7 (rs9913911) and increased cup volume (β = 0.03 mm3, P = 4.60E-02) and mean cup depth (β = 0.03 mm3, P = 4.11E-02; additive model) and decreased pattern standard deviation (β = -0.87 dB, P = 2.44E-02; dominant model).

CONCLUSION

The association between SNPs near GAS7 and POAG was found in Japanese patients for the first time. Clinical characterization of the risk variants is an important step toward understanding the pathology of the disease and optimizing treatment of patients with POAG.

Classification of optic disc shape in glaucoma using machine learning based on quantified ocular parameters

PURPOSE

This study aimed to develop a machine learning-based algorithm for objective classification of the optic disc in patients with open-angle glaucoma (OAG), using quantitative parameters obtained from ophthalmic examination instruments.

METHODS

This study enrolled 163 eyes of 105 OAG patients (age: 62.3 ± 12.6, mean deviation of Humphrey field analyzer: -8.9 ± 7.5 dB). The eyes were classified into Nicolela's 4 optic disc types by 3 glaucoma specialists. Randomly, 114 eyes were selected for training data and 49 for test data. A neural network (NN) was trained with the training data and evaluated with the test data. We used 91 types of quantitative data, including 7 patient background characteristics, 48 quantified OCT (swept-source OCT; DRI OCT Atlantis, Topcon) values, including optic disc topography and circumpapillary retinal nerve fiber layer thickness (cpRNFLT), and 36 blood flow parameters from laser speckle flowgraphy, to build the machine learning classification model. To extract the important features among 91 parameters, minimum redundancy maximum relevance and a genetic feature selection were used.

RESULTS

The validated accuracy against test data for the NN was 87.8% (Cohen's Kappa = 0.83). The important features in the NN were horizontal disc angle, spherical equivalent, cup area, age, 6-sector superotemporal cpRNFLT, average cup depth, average nasal rim disc ratio, maximum cup depth, and superior-quadrant cpRNFLT.

CONCLUSION

The proposed machine learning system has proved to be good identifiers for different disc types with high accuracy. Additionally, the calculated confidence levels reported here should be very helpful for OAG care.

Preperimetric Glaucoma Prospective Observational Study (PPGPS): Design, baseline characteristics, and therapeutic effect of tafluprost in preperimetric glaucoma eye

Purpose

There is no consensus on the diagnosis or treatment policy for Preperimetric Glaucoma (PPG) because the pathogenesis of PPG is not clear at this time. Preperimetric Glaucoma Prospective Observational Study (PPGPS) is a first multicenter, prospective, observational study to clarify the pathogenesis of PPG. This article indicates study design, patient baseline characteristics, and analysis focused on optic nerve head (ONH) blood flow in PPG, as well as the intraocular pressure (IOP) -lowering effect and ONH blood flow-improving effects of Tafluprost.

Method

In this study, 122 eyes from 122 subjects (mean age: 53.1 ± 14.3) newly diagnosed as PPG were enrolled. The circumpapillary retinal nerve fiber layer thickness (cpRNFLT) was evaluated with optical coherence tomography (OCT). The ONH blood flow was measured with laser speckle flowgraphy. The therapeutic effect of Tafluprost was evaluated at Month 0 (ONH blood flow-improving effect) and Month 4 (IOP-lowering effect).

Results

The untreated IOP, cpRNFLT, and baseline Mean deviation (MD) value was 16.4 ± 2.5 mmHg, 80.4 ± 8.2 μm, and -0.48 ± 1.29 dB, respectively. In the site-specific visual field evaluation using the sector map, there was no appreciable site-specific visual field defect in the eye with PPG. The inferior region of cpRNFLT in 4-quadrant OCT sector analysis and 6 o’clock region in 12-o’clock OCT sector analysis was the highest rate of abnormality in PPG eyes. Topical administration of Tafluprost significantly reduced IOP from 16.4 ± 2.5 mmHg at baseline to 14.5 ± 2.3 mmHg at Month 4 (P < 0.001, paired t-test). In the linear regression analysis, there was a significant relationship between the increase of ONH blood flow and baseline value.

Conclusion

PPGPS is a first prospective study focusing on the pathology of PPG. This study is expected to elucidate the pathology of PPG, with evidence useful for determining a treatment strategy for PPG.

Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu

In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a ^{80}Zn beam at 270  MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z=28 gap at N=50 remains large. The results show that the ^{79}Cu nucleus can be described in terms of a valence proton outside a ^{78}Ni core, implying the magic character of the latter.

Usefulness of axonal tract-dependent OCT macular sectors for evaluating structural change in normal-tension glaucoma

Purpose

To identify sectors of the optical coherence tomography (OCT) macular map that could be used to effectively assess structural progression in patients with normal-tension glaucoma (NTG).

Methods

This study examined 117 eyes of 117 NTG patients to establish axonal tract-dependent macular sectors, and also examined a separate group of 122 eyes of 81 NTG patients to evaluate the ability of these sectors to reveal glaucoma progression. Longitudinal data, including macular maps from at least 5 OCT examinations performed over at least 2 years, was available for all patients in this group. Circumpapillary retinal nerve fiber layer thickness (cpRNFLT), temporal clockwise sector scans (from 7 to 11 o’clock), macular retinal nerve fiber layer thickness (mRNFLT), and macular ganglion cell layer plus inner plexiform layer thickness (mGCIPLT) were measured with spectral-domain OCT (3D OCT-2000, TOPCON). The axonal tract-dependent macular sectors were identified by calculating Spearman’s rank correlation coefficient for each point on a grid overlaid on the macular map and cpRNFLT in each clockwise scan sector. Trend and event analyses for the slope of progression in each sector and macular map were performed. Visual field progression in the macula was defined by the presence of more than 2 progressive test points in the 16 central test points of the Humphrey field analyzer SITA standard 24–2 program, evaluated with Progressor software.

Results

The slope of progression in the entire macular area was -0.22 ± 0.58 μm/year for mRNFLT and -0.35 ± 0.52 μm/year for mGCIPLT. The fastest-progressing mRNFLT sector (-1.00 ± 0.84 μm/year, p < 0.001) and mGCIPLT sector (-1.16 ± 0.63 μm/year, p < 0.001) progressed significantly faster than the overall macula. Classifying patients according to visual field progression showed that baseline mRNFLT in the inferior hemifield, 7 and 8 o’clock sectors, as well as baseline mGCIPLT in the overall macular map, inferior hemifield, and 8 o’clock sector, were significantly lower in progressors (22 eyes) than non-progressors (100 eyes). There were significant differences in mRNFLT slope in 8 o’clock sector and in the fastest progressing sector in progressors and non-progressors, but mGCIPLT did not differ, even in the fastest-progressing sector. Event analysis showed that progression occurred most frequently in inferior mRNFLT and superior mGCIPLT in this study.

Conclusion

Axonal tract-dependent OCT macular sectors could effectively reveal structural change in patients with NTG. Furthermore, mRNFLT slope was consistent with visual field progression. This method promises to open new avenues for the OCT-based evaluation of glaucoma progression.

Additive effects of genetic variants associated with intraocular pressure in primary open-angle glaucoma

To investigate the association between the additive effects of genetic variants associated with intraocular pressure (IOP) and IOP, vertical cup-to-disc ratio (VCDR), and high tension glaucoma (HTG) or normal tension glaucoma (NTG) as phenotypic features of primary open-angle glaucoma (POAG), and to evaluate the clinical usefulness of the additive effects of IOP-related genetic variants for predicting IOP elevation, Japanese patients with HTG (n = 255) and NTG (n = 261) and 246 control subjects were genotyped for nine IOP-related genetic variants near CAV2, GAS7, GLCCI1/ICA1, ABCA1, ARHGEF12, FAM125B, FNDC3B, ABO, and PTPRJ/AGBL2. The total number of risk alleles of these genetic variants was calculated for each participant as a genetic risk score (GRS), and the association between the GRS and the maximum IOP, mean VCDR, and phenotype (HTG or NTG) of POAG was evaluated. As the GRS increased, the maximum IOP (P = 0.012) and VCDR (P = 0.010) significantly increased. The GRS (9.1±1.9) in patients with HTG was significantly higher (P = 0.011) than that (8.7±1.8) in control subjects. The patients with GRS≥12 as a cut-off value had a 2.54 times higher (P = 0.0085) risk on HTG (maximum IOP≥22mmHg) compared with all patients. The IOP-related GRS approach substantiated that the IOP and VCDR were increased by the additive effects of IOP-related genetic variants in POAG. The high IOP-related GRS in patients with HTG but not NTG shows that there are differences in the genetic background between HTG and NTG and supports the notion that the phenotype (HTG or NTG) in patients with POAG depends on the additive effects of IOP-related genetic variants. The above-mentioned cut-off value of IOP-related GRS may be clinically useful for predicting the risk of IOP elevation.

Age- and sex-dependency of the association between systemic antioxidant potential and glaucomatous damage

Systemic oxidative stress is thought to be an important factor in the pathogenesis of glaucoma. In particular, low systemic antioxidative capacity, which normally counters oxidative stress, may contribute to glaucoma. Thus, we investigated the association between biological antioxidant potential (BAP), a biomarker of systemic antioxidative capacity, and glaucoma severity in patients with open-angle glaucoma (OAG). This study included 480 eyes of 240 patients with OAG and 66 healthy control eyes. We measured the BAP serum level with a free radical analyzer and compared it with a weighted estimate of the number of retinal ganglion cells (wrgc), derived from circumpapillary retinal nerve fiber layer thickness and visual field mean deviation. We found that wrgc was uncorrelated with BAP in the overall, male, and female OAG patients, but was correlated in young (aged ≤ 65 years) male OAG patients (better eye: r = 0.33, P = 0.02; worse eye: r = 0.27, P = 0.047). Furthermore, a mixed-effects regression analysis revealed that BAP was an independent contributing factor to wrgc in young male OAG patients (P = 0.02). Thus, systemic antioxidant capacity was associated with glaucomatous damage in relatively young male patients, suggesting that anti-oxidant therapy might be more effective in these patients.

The neuroprotective effect of hesperidin in NMDA-induced retinal injury acts by suppressing oxidative stress and excessive calpain activation

We found that hesperidin, a plant-derived bioflavonoid, may be a candidate agent for neuroprotective treatment in the retina, after screening 41 materials for anti-oxidative properties in a primary retinal cell culture under oxidative stress. We found that the intravitreal injection of hesperidin in mice prevented reductions in markers of the retinal ganglion cells (RGCs) and RGC death after N-methyl-D-aspartate (NMDA)-induced excitotoxicity. Hesperidin treatment also reduced calpain activation, reactive oxygen species generation and TNF-α gene expression. Finally, hesperidin treatment improved electrophysiological function, measured with visual evoked potential, and visual function, measured with optomotry. Thus, we found that hesperidin suppressed a number of cytotoxic factors associated with NMDA-induced cell death signaling, such as oxidative stress, over-activation of calpain, and inflammation, thereby protecting the RGCs in mice. Therefore, hesperidin may have potential as a therapeutic supplement for protecting the retina against the damage associated with excitotoxic injury, such as occurs in glaucoma and diabetic retinopathy.