Distinct retinal reflectance spectra from retinal hyperspectral imaging in Parkinson's disease.

BACKGROUND: Recent developments in the retinal hyperspectral imaging method have indicated its potential in addressing challenges posed by neurodegenerative disorders, such as Alzheimer's disease. This human clinical study is the first to assess reflectance spectra obtained from this imaging as a tool for diagnosing patients with Parkinson's disease (PD). METHODS: Retinal hyperspectral imaging was conducted on a total of 40 participants, including 20 patients with PD and 20 controls. Following preprocessing, retinal reflectance spectra were computed for the macular retina defined by four rectangular regions. Linear discriminant analysis classifiers underwent training to discern patients with PD from control participants. To assess the performance of the selected features, nested leave-one-out cross-validation was employed using machine learning. The indicated values include the area under the curve (AUC) and the corresponding 95% confidence interval (CI). RESULTS: Retinal reflectance spectra of PD patients exhibited variations in the spectral regions, particularly at shorter wavelengths (superonasal retina, wavelength < 490 nm; inferonasal retina, wavelength < 510 nm) when compared to those of controls. Retinal reflectance spectra yielded an AUC of 0.60 (95% CI: 0.43-0.78) and 0.60 (95% CI: 0.43-0.78) for the superonasal and inferonasal retina, respectively, distinguishing individuals with and without PD. CONCLUSION: Reflectance spectra obtained from retinal hyperspectral imaging tended to decrease at shorter wavelengths across a broad spectral range in PD patients. Further investigations building upon these preliminary findings are imperative to focus on the retinal spectral signatures associated with PD pathological hallmarks, including α-synuclein.

Association between retinopathy and risk of dementia in a general Japanese population: the Hisayama Study.

We investigated the association of retinopathy with the risk of dementia in a general older Japanese population. A total of 1709 population-based residents aged 60 years or older without dementia were followed prospectively for 10 years (2007-2017). They underwent color fundus photography in 2007. Retinopathy was graded according to the Modified Airlie House Classification. Main outcome was the Incidence of dementia. A Cox proportional hazards model was used to estimate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for the risk of dementia by the presence of retinopathy. During the follow-up period, 374 participants developed all-cause dementia. The cumulative incidence of dementia was significantly higher in those with retinopathy than those without (p < 0.05). Individuals with retinopathy had significantly higher risk of developing dementia than those without after adjustment for potential confounding factors (HR 1.64, 95% CI 1.19-2.25). Regarding the components of retinopathy, the presence of microaneurysms was significantly associated with a higher multivariable-adjusted HR for incident dementia (HR 1.94, 95% CI 1.37-2.74). Our findings suggest that, in addition to systemic risk factors, retinal microvascular signs from fundus photography provide valuable information for estimating the risk of developing dementia.

Association between corneal hysteresis and glaucoma in a Japanese population: the Hisayama Study.

AIMS: To investigate the association between corneal hysteresis and the presence of glaucoma and its subtypes in a general Japanese population. METHODS: We analysed the data of 2338 Japanese community-dwellers aged ≥40 years (1059 men, 1279 women) who underwent an eye examination in 2018 as part of the population-based, cross-sectional Hisayama Study. Participants were divided into quartile levels of corneal hysteresis, which had been measured with an ocular response analyzer. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. We conducted a logistic regression analysis to determine the ORs and their 95% CIs for the presence of outcomes according to the corneal hysteresis quartiles. RESULTS: Glaucoma was diagnosed in 154 participants: primary open-angle glaucoma (POAG), n=115; primary angle-closure glaucoma, n=17; exfoliation glaucoma, n=21 and secondary glaucoma without exfoliation glaucoma, n=1. After adjustment for confounders, the OR for prevalent glaucoma was significantly increased in the participants in the first corneal-hysteresis quartile compared with those in the fourth quartile (OR: 1.80; 95% CI: 1.03 to 3.17). Regarding glaucoma subtypes, the first-quartile participants had significantly greater likelihoods of the presence of POAG (OR: 1.63; 95% CI: 1.02 to 2.61) and exfoliation glaucoma (OR: 6.49; 95% CI: 1.44 to 29.30) compared with those in the third and fourth quartiles after adjustment for potential confounders. CONCLUSIONS: These results demonstrated a significant inverse association between corneal hysteresis and the likelihood of glaucoma, suggesting that the measurement of corneal hysteresis would provide useful information for elucidating the aetiology of glaucoma.

Impact of Concurrent Visual and Hearing Impairment on Incident Alzheimer's Disease: The LIFE Study.

Background: The prevalence of Alzheimer's disease (AD) is increasing in Japan due to population aging. The association between sensory impairment and incident AD remains unclear. Objective: This study aimed to investigate the impact of sensory impairment on incident AD. Methods: We analyzed residents of five municipalities participating in the Longevity Improvement & Fair Evidence (LIFE) Study. The participants comprised individuals who had newly applied for long-term care needs certification between 2017 and 2022 and had no cognitive impairment upon application or AD diagnosis within the preceding six months. Participants were classified according to sensory impairment status: visual impairment (VI), hearing impairment (HI), neither sensory impairment (NSI), and dual sensory impairment (DSI). The month succeeding the certification application was set as the index month, and the interval from that month until AD onset was assessed. Multivariable Cox proportional hazards analysis was performed to calculate the risk of AD onset according to sensory impairment status while adjusting for sex, age, dependence level, self-reliance level, and comorbidities. Results: Among 14,186 participants, we identified 1,194 (8.4%) who developed AD over a median follow-up period of 22.6 months. VI and HI only were not associated with incident AD. However, DSI conferred a significantly higher risk (HR: 1.6, CI: 1.1-2.2, p = 0.008) of AD onset than NSI. Conclusions: Individuals with concurrent DSI have a higher risk of developing AD than those with single or NSI. Preventing and treating sensory impairment may not only improve functional outcomes, but could also help to reduce the future risk of AD.

Association Between Choroidal Thickness and Myopic Maculopathy in a Japanese Population: The Hisayama Study.

Purpose: To examine the association between choroidal thickness and myopic maculopathy in a general Japanese population. Design: Population-based cross-sectional study. Participants: A total of 2841 residents of a Japanese community aged ≥ 40 years, who consented to participate and had available data of choroidal thickness and fundus photographs, were enrolled in this study. Methods: The choroidal thickness was measured by swept-source OCT. Participants were divided into quartiles of choroidal thickness. Myopic maculopathy was defined according to the classification system of the Meta-analysis of Pathologic Myopia Study Group. Main outcome measures were odds ratios (ORs) of choroidal thickness for prevalent myopic maculopathy. The ORs and 95% confidence intervals (CIs) were estimated using a logistic regression model. Main Outcome Measures: Prevalent myopic maculopathy. Results: Eighty-one participants had myopic maculopathy (45 diffuse chorioretinal atrophy, 31 patchy chorioretinal atrophy, and 5 macular atrophy). Individuals in the lowest quartile of choroidal thickness had a significantly greater OR for the presence of myopic maculopathy than those in the highest quartile of choroidal thickness (OR: 4.78 [95% CI: 1.78-16.72]) after adjusting for confounders, including axial length. The sensitivity analysis among the 1176 myopic individuals with axial length of ≥ 24.0 mm also showed that thinner choroidal thickness was significantly associated with prevalent myopic maculopathy. Conclusions: The present study demonstrated the significant inverse association between choroidal thickness and the likelihood of myopic maculopathy, suggesting that the measurement of choroidal thickness in addition to axial length would be useful for assessing the risk of myopic maculopathy and elucidating its pathogenesis. Financial Disclosures: Proprietary or commercial disclosure may be found after the references.

Secular trends in the prevalence, incidence, and progression of diabetic retinopathy: the Hisayama Study.

PURPOSE: To examine the secular trends in the prevalence, incidence, and progression rates of diabetic retinopathy (DR) in a Japanese community. METHODS: Community-dwelling Japanese residents aged ≥ 40 years with diabetes participated in comprehensive systemic and ophthalmological surveys, including an examination for DR, in 1998 (n = 220), 2007 (n = 511), 2012 (n = 515), and 2017 (n = 560). DR was assessed using colour fundus photographs after pupil dilation according to the modified Airlie House classification system. To compare the frequencies of newly developed or progressed DR between the studied decades, two eye cohorts were established (the 2000s cohort included 145 participants examined in 1998 and 2007; the 2010s cohort included 255 participants examined in 2007, 2012, and 2017). Trends in the prevalence, incidence, and progression rate of DR were tested by logistic regression analysis with a generalised estimating equation. RESULTS: The age-adjusted prevalence of DR among individuals with diabetes decreased significantly with time from 1998 to 2017 (27.4% in 1998, 22.8% in 2007, 12.8% in 2012, and 6.4% in 2017; p for trend < 0.001). During this period, the prevalence of DR was decreasing in every haemoglobin A1c category, but it remained constant in the high systolic blood pressure category. In addition, the rates of new-onset of DR were significantly lower in the 2010s compared to the 2000s (p < 0.001). CONCLUSION: Our findings suggest that the prevalence and incidence of DR among diabetic people significantly decreased with time over the past two decades in a general Japanese population.

Prevalence of Glaucoma and Its Systemic Risk Factors in a General Japanese Population: The Hisayama Study.

Purpose: To estimate the prevalence of glaucoma and its risk factors in a Japanese community. Methods: This study included 3405 Japanese community dwellers who were ≥40 years of age and enrolled in the Hisayama Study. This population-based, cross-sectional study was conducted from 2017 to 2018. A glaucoma screening test was performed using stereo fundus images and swept-source optical coherence tomography. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. Results: The prevalence of glaucoma was 7.6% (95% confidence interval [CI], 6.7-8.6) overall. The prevalence of primary open-angle glaucoma (POAG) was 5.8% (95% CI, 5.0-6.6); that of primary angle-closure glaucoma (PACG) was 0.7% (95% CI, 0.5-1.1); and that of exfoliation glaucoma was 1.1% (95% CI, 0.7-1.4). In addition to aging, lower estimated glomerular filtration rate (eGFR) (odds ratio [OR] = 1.15; 95% CI, 1.02-1.33), higher intraocular pressure (OR = 1.06; 95% CI, 1.01-1.12), longer axial length (OR = 1.44; 95% CI, 1.31-1.59), and thinner central corneal thickness (CCT) (OR = 1.09; 95% CI, 1.04-1.15) were significant risk factors for POAG. Diabetes (OR = 2.81; 95% CI, 1.19-6.62) was a significant risk factor for PACG, and diabetes (OR = 2.15; 95% CI, 1.03-4.47) and thinner CCT (OR = 1.14; 95% CI, 1.02-1.28) were significant risk factors for exfoliation glaucoma. Conclusions: The prevalence of glaucoma was approximately 8%, probably due to the increase in the Japanese aging population. Not only ocular factors but also lower eGFR for POAG and diabetes for PACG and exfoliation glaucoma were risk factors in a general Japanese population. Translational Relevance: Systemic factors such as eGFR and diabetes must also be considered when implementing preventive measures against glaucoma.

Association of Inner Retinal Thickness with Prevalent Dementia and Brain Atrophy in a General Older Population: The Hisayama Study.

Purpose: To assess the association of inner retinal thickness with prevalent dementia and regional brain atrophy in a general older population of Japanese. Design: Population-based, cross-sectional study. Participants: A total of 1078 residents aged 65 years or older who participated in an eye examination, a comprehensive survey of dementia, and brain magnetic resonance imaging scanning in 2017. Methods: The thicknesses of the inner retinal layers, namely, the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL)-were measured by swept-source OCT (SS-OCT). The association of these retinal thicknesses with the risk of the presence of dementia was estimated using restricted cubic splines and logistic regression models. Regional brain volumes were estimated separately by applying 2 different methods: voxel-based morphometry (VBM) and analysis by FreeSurfer software. The associations of GC-IPL and RNFL thickness with each brain regional volume were analyzed using multiple regression analysis. Main Outcome Measure: Prevalent dementia and regional brain atrophy. Results: Among the study participants, 61 participants (5.7%) were diagnosed with dementia. The likelihood of the presence of dementia significantly increased with lower GC-IPL thickness after adjusting for potential confounders (odds ratio, 1.62 [95% confidence interval, 1.30-2.01] per 1 standard deviation decrement in the GC-IPL thickness), but no significant association was observed with RNFL thickness. In the VBM analyses with the multivariable adjustment, lower GC-IPL thickness was significantly associated with lower volume of known brain regions related to cognitive functions (i.e., the hippocampus, amygdala, entorhinal area, and parahippocampal gyrus) and visual functions (i.e., the cuneus, lingual gyrus, and thalamus). Meanwhile, the volume of the thalamus significantly decreased with lower RNFL thickness, but none of the brain regions related to cognitive function exhibited a volume change in association with RNFL thickness. The sensitivity analysis using FreeSurfer analysis also showed that lower GC-IPL thickness was significantly associated with lower regional brain volume/intracranial volume of the hippocampus, amygdala, cuneus, lingual gyrus, and thalamus. Conclusions: Our findings suggest that the measurement of GC-IPL thickness by SS-OCT, which is a noninvasive, convenient, and reproducible method, might be useful for identifying high-risk individuals with dementia.

Cohort Profile: The Ganka-Ekigaku Network (GEN), a Network of Japanese Ophthalmological Epidemiology Studies.

PURPOSE: Japan has been known as a super-aged society, and ageing is a well-known risk factor for blinding eye diseases. However, epidemiological studies in ophthalmology are still scarce in Japan, and the sizes of the cohorts are relatively small. "Ganka-Ekigaku Network" (GEN, an acronym for the epidemiological network in ophthalmology in Japanese) is established to develop a capacity to boost each epidemiological study and enrich a potential inter-study collaboration to identify risk factors of visual impairment in aged society. METHODS: We reviewed cohort studies in Japan with the inclusion criteria as: (1) at least n = 1000 at baseline, (2) multiple modalities of ophthalmic data, and (3) diagnosis reviewed by ophthalmologist(s), and (4) ophthalmologists are involved in the investigators group. As of January 2020, GEN includes 4 individual Japanese epidemiological studies namely, Hisayama study, Yamagata Study (Funagata), Tsuruoka Metabolomics Cohort study, and the Nagahama Prospective Genome Cohort for Comprehensive Human Bioscience. RESULTS: GEN includes approximately 25,000 Japanese participants. The baseline surveys started from 1998 to 2012, and since then the data has been prospectively collected approximately every 5 years. A variety of ophthalmic measurements and other factors have been collected in each study in GEN: ophthalmic measurements (fundus photography, optical coherence tomography, etc.), systemic conditions (laboratory data, etc.), and others (DNA, etc.). CONCLUSION: GEN is an open platform for observational ophthalmic epidemiological studies to share standardized methodologies. While each study in GEN pursues specific and original research questions, standardization of the methods will enable us to conduct reliable meta-analysis/pooled data analyses.

Risk factors for myopia at 1-year corrected age following laser photocoagulation for retinopathy of prematurity.

BACKGROUND/OBJECTIVES: The prevalence of myopia is higher in preterm infants who underwent laser photocoagulation (LPC) for retinopathy of prematurity (ROP). The aim of this study was to investigate factors associated with myopia in preterm infants who undergo LPC for ROP. SUBJECTS/METHODS: We retrospectively analysed the medical records of preterm infants born at Kyushu University Hospital (October 2008-March 2018) at ≤32 weeks of gestational age or with birth weight ≤1500 g. We evaluated the associations between nine clinical factors and the spherical equivalent at 1-year corrected age by performing multivariable linear regression in LPC-treated ROP patients. RESULTS: Among the 485 infants enroled, 76 developed ROP requiring treatment. Of these, 71 underwent LPC, which was provided to 63 infants as the primary treatment (LPC alone or the combination therapy of LPC and intravitreal injection of bevacizumab [IVB]) and to eight infants as additional LPC after IVB monotherapy. The results of a refractive examination at 1-year corrected age were available for 110 eyes of 56 infants (78.9%). The mean ± standard deviation of the SE value was -0.5 ± 3.0 dioptres (D). Multivariable linear regression analysis revealed a significant association between laser spot count and SE value (ß = -0.081 ± 0.040 D per 100 spots [mean ± standard error], p = 0.045). CONCLUSIONS: Our results suggest that an increased laser spot count observed during ROP treatment associates with myopia.

Five-Year Incidence of Myopic Maculopathy in a General Japanese Population: The Hisayama Study.

Importance: Myopic maculopathy is a leading cause of irreversible visual impairment worldwide. Moreover, the burden of myopic maculopathy has been expected to increase owing to the rising prevalence of myopia globally. However, there is limited epidemiologic evidence regarding the incidence of and risk factors for myopic maculopathy. This study from Japan, with a relatively high prevalence of myopia, could provide valuable information related to these issues. Objective: To estimate the incidence of myopic maculopathy and its risk factors in Hisayama in southwestern Japan. Design, Setting, and Participants: A population-based prospective cohort study in a Japanese community in Hisayama, Japan. The study included a total of 2164 residents 40 years or older who had no myopic maculopathy at the baseline eye examination in 2012 and underwent follow-up eye examinations in 2017. Main Outcomes and Measures: Incidence of myopic maculopathy. The grades of myopic maculopathy were categorized based on the criteria of the Meta-analysis of Pathologic Myopia Study Group classification system. Results: The mean (SD) age of the study participants was 62.4 (10.9) years, and the proportion of men was 42.5% (920 participants). In the follow-up examination in 2017, 24 patients developed myopic maculopathy. The 5-year cumulative incidence of myopic maculopathy was 1.1% (95% CI, 0.6-1.5) overall, 1.4% (95% CI, 0.6-2.2) for men, and 0.9% (95% CI, 0.4-1.4) for women. Multiple logistic regression analysis showed that older age (per 1 year; odds ratio [OR], 1.06; 95% CI, 1.01-1.11) and longer axial length (per 1 mm; OR, 2.94; 95% CI, 2.19-3.95) were associated with incident myopic maculopathy. Conclusions and Relevance: Twenty-four study participants (1%) developed myopic maculopathy during the 5-year study period, which is much higher than the rate in a previous study on a Chinese population. We also confirmed that aging and longer axial length were independent and significant risk factors for myopic maculopathy. These findings should be reviewed among various populations in other parts of the world.

Trends in the Prevalence of Myopia and Myopic Maculopathy in a Japanese Population: The Hisayama Study.

Purpose: To examine trends in the prevalence of myopia and myopic maculopathy in a general Japanese population. Methods: Residents of a Japanese community aged 40 years and older participated in surveys conducted in 2005, 2012, and 2017. Each participant underwent comprehensive eye examinations that included measurements of refractive error, axial lengths, and color fundus photography. Myopic maculopathy was defined according to the criteria of the Meta-analysis of Pathologic Myopia Study Group classification system. Trends in the prevalence of myopia and myopic maculopathy were tested by using a logistic regression analysis fitted by generalized estimating equations to account for individuals submitting to repeated examination. Results: The age-adjusted frequencies of myopia increased significantly from 2005 to 2017 (myopia, 37.7%-45.8%; high myopia 5.8%-9.5%; all P for trend <0.001). The age-adjusted frequency of an axial length level of 26.5 mm or more increased significantly from 2005 to 2017 (3.6%-6.0%; P for trend <0.001). The age-adjusted prevalence of myopic maculopathy also increased significantly with time (1.6% in 2005, 3.0% in 2012 and 3.6% in 2017; P for trend <0.001). Upward trends were observed in the prevalence of diffuse chorioretinal atrophy and patchy chorioretinal atrophy (all P for trend <0.05). Conclusions: Our findings suggest that the prevalence of myopia and myopic maculopathy, especially diffuse chorioretinal atrophy and patchy chorioretinal atrophy, increased significantly over the past 12 years in a general Japanese population.

Association between Axial Length and Myopic Maculopathy: The Hisayama Study.

PURPOSE: To assess the association between axial length (AL) and the prevalence of myopic maculopathy in a general Japanese population. DESIGN: Population-based cross-sectional study. PARTICIPANTS: A total of 2790 Hisayama residents 40 years of age or older who consented to participate and had available data of AL and fundus photographs for the right eyes were enrolled in this study. METHODS: Myopic maculopathy was defined as the presence of diffuse chorioretinal atrophy, patchy chorioretinal atrophy, or macular degeneration. The optimal cutoff values of axial length for identifying myopic maculopathy were estimated from the receiver operating characteristic curve. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using a logistic regression analysis. MAIN OUTCOME MEASURES: Odds ratios of AL for prevalent myopic maculopathy and the optimal cutoff values of AL for detecting myopic maculopathy. RESULTS: Longer AL was associated significantly with prevalence of myopic maculopathy in both genders. The optimal cutoff values of AL for identifying myopic maculopathy were 25.9 mm in men and 25.3 mm in women. Participants with ALs of these values or longer showed a significantly higher OR for myopic maculopathy than those with AL of less than these values (men: OR, 21.23; 95% CI, 8.74-51.57; women: OR, 38.49; 95% CI, 18.03-86.49). CONCLUSIONS: The present study found that there was a positive association between AL and the likelihood of myopic maculopathy, and the cutoff levels of AL for identifying myopic maculopathy were 25.9 mm in men and 25.3 mm in women. Our findings suggest that patients with AL close to or longer than these values should undergo intensive treatment and detailed ophthalmic follow-up.

Association of rs613872 and Trinucleotide Repeat Expansion in the TCF4 Gene of German Patients With Fuchs Endothelial Corneal Dystrophy.

PURPOSE: To investigate single nucleotide polymorphisms (SNPs) and trinucleotide repeat (TNR) expansion in the transcription factor 4 (TCF4) gene in a large cohort of German patients with Fuchs endothelial corneal dystrophy (FECD). METHODS: Genomic DNA was obtained from 398 patients with FECD and from 58 non-FECD controls. Thirty-seven previously reported SNPs were evaluated by genotyping. The 398 FECD samples were analyzed for TNR expansions by short tandem repeat assays and Southern blotting. The possible associations between the TNR length and clinical parameters (age, sex, visual acuity, and central corneal thickness) were analyzed in 132 patients. RESULTS: The SNPs in COL8A2, TCF8, LOXHD1, and AGBL1 showed no heterogeneity in 36 cases, although SLCA411 showed 3 nonsense mutations. SNPs were detected for TCF4 (rs613872, rs2123392, rs17089887, rs1452787, and rs1348047), but only rs613872 showed a significant association with FECD (P = 9.93 × 10). Overall, 315/398 (79%) patients harbored TNR lengths >50, whereas no non-FECD controls harbored TNR lengths >50. The TCF4 SNP rs613872 genotype was TT: 39 (67%), TG: 18 (31%), and GG: 1 (2%) in non-FECD controls; TT: 39 (47%), TG: 38 (46%), and GG: 6 (7%) in FECD cases harboring TNR <50; and TT: 23 (8%), TG: 224 (79%), and GG: 38 (13%) in FECD cases harboring TNR >50 (P = 2.93 × 10). No significant association was detected between the TNR length and clinical parameters. CONCLUSIONS: Our large German cohort demonstrated a significant association between the risk allele G in rs613872 and FECD, irrespective of TNR expansion, although this risk allele was more frequent in FECD cases with TNR expansion than without.

Glucose Tolerance Levels and Circumpapillary Retinal Nerve Fiber Layer Thickness in a General Japanese Population: The Hisayama Study.

PURPOSE: To investigate the relationship between glucose tolerance levels and the circumpapillary retinal nerve fiber layer thickness (cpRNFLT) in a general Japanese population. DESIGN: Population-based, cross-sectional study. METHODS: In 2012 and 2013, a total of 2809 Japanese community dwellers aged 40-79 years in the Hisayama Study underwent eye examinations including cpRNFLT measurement with spectral domain optical coherence tomography. Of these, 1324 subjects (578 men and 746 women) were enrolled. Glucose tolerance levels were determined by a 75-g oral glucose tolerance test. We conducted an analysis of covariance to estimate the mean values of cpRNFLT according to the subjects' glucose intolerance status. RESULTS: The subjects with prediabetes or with diabetes mellitus had significantly lower age- and sex-adjusted mean cpRNFLT values than those with normal glucose tolerance (P = .04 and P = .0004, respectively). The age- and sex-adjusted mean values of cpRNFLT decreased significantly with elevating fasting plasma glucose and 2-hour postload glucose levels (all P for trend < .05). These associations were substantially unchanged after adjustment for potential confounding factors. The coexistence of poorer glucose tolerance and higher intraocular pressure levels was additively associated with thinner cpRNFLT. CONCLUSIONS: Our analyses revealed that poorer glucose tolerance was significantly associated with the reduction of cpRNFLT in a Japanese general population, suggesting that the loss of neural tissue in the eye begins at the prediabetic stage, and that hyperglycemia may play a role in the reduction of cpRNFLT.

Activation of TGF-ß signaling induces cell death via the unfolded protein response in Fuchs endothelial corneal dystrophy.

Fuchs endothelial corneal dystrophy (FECD) is a slowly progressive bilateral disease of corneal endothelium in which accumulation of extracellular matrix (ECM) and loss of corneal endothelial cells (CECs) are phenotypic features. The corneal endothelium maintains corneal transparency by regulating water hydration; consequently, corneal endothelial dysfunction causes serious vision loss. The only therapy for corneal haziness due to corneal endothelial diseases, including FECD, is corneal transplantation using donor corneas, and no pharmaceutical treatment is available. We provide evidence that the expression levels of transforming growth factor-ß (TGF-ß) isoforms and TGF-ß receptors are high in the corneal endothelium of patients with FECD. A cell model based on patients with FECD shows that TGF-ß signaling induced a chronic overload of ECM proteins to the endoplasmic reticulum (ER), thereby enhancing the formation of unfolded protein and triggering the intrinsic apoptotic pathway through the unfolded protein response (UPR). We propose that inhibition of TGF-ß signaling may represent a novel therapeutic target that suppresses cell loss as well as the accumulation of ECM in FECD.

Sustained Activation of the Unfolded Protein Response Induces Cell Death in Fuchs' Endothelial Corneal Dystrophy.

Purpose: The unfolded protein response (UPR) is believed to play a role in the pathogenesis of Fuchs' endothelial corneal dystrophy (FECD). The purpose of this study was to investigate whether unfolded proteins accumulate in the corneal endothelium in FECD and if they are involved in triggering cell death. Methods: Descemet's membranes with corneal endothelial cells (CECs) were obtained during keratoplasty, and expression of aggresomes, type 1 collagen, fibronectin, and agrin was evaluated. Endoplasmic reticulum (ER) stress of immortalized human CECs from non-FECD subjects and from FECD patients (iHCEC and iFECD, respectively) were evaluated. The effect of MG132-mediated aggresome formation on the UPR and intrinsic pathway and the effect of mitochondrial damage on UPR were also examined. The effect of CHOP knockdown on the ER stress-mediated intrinsic pathway was also evaluated. Results: Aggresome formation was higher in iFECD than in iHCEC and was colocalized with type 1 collagen, fibronectin, and agrin. GRP78, phosphorylated IRE1, PERK, and CHOP showed higher activation in iFECD than in iHCEC. MG132-mediated aggresome formation upregulated ER stress sensors, the mitochondrial membrane potential drop, cytochrome c release to the cytoplasm, and activation of caspase-9 and -3. By contrast, staurosporine-mediated mitochondrial damage did not induce ER stress. Knockdown of CHOP attenuated the ER stress-induced cleavage of caspase-9, which is caused by intrinsic pathway activation. Conclusions: Excessive synthesis of extracellular matrix proteins induced unfolded protein accumulation in FECD. Prolonged ER stress-mediated cell death, occurring via the intrinsic apoptotic signaling pathway, therefore might be associated with the pathogenesis of FECD.

RANK-RANKL interactions are involved in cell adhesion-mediated drug resistance in multiple myeloma cell lines.

Interaction between multiple myeloma (MM) cells and the bone marrow microenvironment plays a critical role in MM pathogenesis and the development of drug resistance. Recently, it has been reported that MM cells express the receptor activator of nuclear factor-κB (NF-κB) (RANK). However, the role of the RANK/RANK ligand (RANKL) system in drug resistance remains unclear. In this study, we demonstrated a novel function of the RANK/RANKL system in promoting drug resistance in MM. We found that RANKL treatment induced drug resistance in RANK-expressing but not RANK-negative cell lines. RANKL stimulation of RANK-expressing cells increased multidrug resistance protein 1 (MDR1), breast cancer resistance protein (BCRP), and lung resistance protein 1 (LRP1) expression and decreased Bim expression through various signaling molecules. RNA silencing of Bim expression induced drug resistance, but the RANKL-mediated drug resistance could not be overcome through the RNA silencing of MDR1, BCRP, and LRP1 expression. These results indicate that the RANK/RANKL system induces chemoresistance through the activation of multiple signal transduction pathways and by decreasing Bim expression in RANK-positive MM cells. These findings may prove to be useful in the development of cell adhesion-mediated drug resistance inhibitors in RANK-positive MM cells.

Risk Factors and Preventive Effects of Laser Panretinal Photocoagulation for Neovascular Glaucoma after Ophthalmic Stereotactic Radiotherapy.

Purpose: To evaluate the risk factors and the preventive effects of laser panretinal photocoagulation (PRP) for neovascular glaucoma (NVG) after ophthalmic stereotactic radiotherapy. Methods: Twenty-four patients with ocular malignant tumor (such as uveal malignant melanoma, lacrimal gland cancer) who received stereotactic radiotherapy (such as gamma knife, cyber knife) were retrospectively analyzed. Patients were divided into group A without preventive PRP (n=9), and group B with preventive PRP (n=15). Survival curves were plotted using the Kaplan-Meier method and compared between the two groups with the log-rank test. Results: In group A, NVG occurred in 3 patients. In contrast, in group B, no patient encountered NVG. The significant risk factor for NVG was dose-volumes that irradiated the optic disk (p=0.045). The incidence of NVG was significantly reduced in group B compared with group A (p=0.019). Conclusions: Dose-volumes that irradiated the optic disk were risk factors for NVG. PRP is effective in the prevention of NVG.

Octreotide improves early dumping syndrome potentially through incretins: a case report.

Dumping syndrome, or rapid gastric emptying, is a frequent complication after gastric surgery. In this case, the patient was a 47-year-old woman who 10 years previously had undergone distal gastrectomy with Billroth I reconstruction for early-stage gastric cancer. She presented with symptoms of weakness, headache, palpitation, sweating, dizziness and significant fatigue between one and two hours after a meal. Because a 75 g oral glucose tolerance test (75 g-OGTT) induced both acute postprandial tachycardia (within 1 hour) and postprandial hypoglycemia, we diagnosed this patient with early and late dumping syndrome. Dietary measures and acarbose improved symptoms of late dumping syndrome but did not prevent the symptoms of early dumping syndrome such as postprandial tachycardia, weakness, headache, palpitation, and dizziness. We therefore used the somatostatin analogue octreotide, which has been reported as an effective therapy for early dumping syndrome. Octreotide prevented the symptoms of early dumping syndrome, especially postprandial tachycardia, but caused postprandial hyperglycemia. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were completely suppressed during the 75 g-OGTT following subcutaneous injection of octreotide. No change was observed in vasoactive intestinal polypeptide (VIP), which is the gastrointestinal peptide hormone generally responsible for early dumping syndrome, suggesting possible contribution of incretins in early dumping syndrome of this patient.