Progression of Neuronal Damage in an In Vitro Model of the Ischemic Penumbra

Improvement of neuronal recovery in the ischemic penumbra around a brain infarct has a large potential to advance clinical recovery of patients with acute ischemic stroke. However, pathophysiological mechanisms leading to either recovery or secondary damage in the penumbra are not completely understood. We studied neuronal dynamics in a model system of the penumbra consisting of networks of cultured cortical neurons exposed to controlled levels and durations of hypoxia. Short periods of hypoxia (pO₂≈20mmHg) reduced spontaneous activity, due to impeded synaptic function. After ≈6 hours, activity and connectivity partially recovered, even during continuing hypoxia. If the oxygen supply was restored within 12 hours, changes in network connectivity were completely reversible. For longer periods of hypoxia (12–30 h), activity levels initially increased, but eventually decreased and connectivity changes became partially irreversible. After ≈30 hours, all functional connections disappeared and no activity remained. Since this complete silence seemed unrelated to hypoxic depths, but always followed an extended period of low activity, we speculate that irreversible damage (at least partly) results from insufficient neuronal activation. This opens avenues for therapies to improve recovery by neuronal activation.     

Effect of cytidine diphosphate choline (CDP-choline) on ischemia-induced alterations of brain lipid in the gerbil

Brain ischemia was produced in gerbils (Meriones unguiculatus) by the bilateral ligation of the carotid arteries. Definite changes in the energy status of brain demonstrated that carotid occlusion was effective. Five minutes before ligation, an intraventricular injection of either saline or cytidine diphosphate choline (CDP-choline, 0.6 mol/brain, 3l) was given to groups of animals. Control animals, with and without CDP-choline, together with the ischemic groups, were decapitated directly into liquid nitrogen; 10 min after arterial ligation. Brain free fatty acids, neutral lipids and phospholipids, which were labeled in vivo by the intraventricular injection of [1-¹⁴C] arachidonic acid (0.4–0.6 Ci, 6–9 nmol) 2 hr prior to ligation, were extracted, purified, and separated by thin-layer chromatographic procedures. The CDP-choline treatment noticeably corrected the increase of total and individual fatty acids due to ischemia and the increase of their radioactivity content. The changes in neutral lipids, particularly in the diacyl glycerol fraction, were also corrected by the injection of the nucleotide. CDP-choline partially reversed the decrease of brain phosphatidylcholine and of its labeling, which was due to ischemia. All the data indicate that the prior injection of CDP-choline stimulates the choline phosphotransferase reaction of brain towards synthesis of phosphatidylcholine and prevents the release of free fatty acids, particularly of arachidonic acid, associated with ischemia.     

Training the Brain to Survive Stroke

Background

Presently, little can be done to repair brain tissue after stroke damage. We hypothesized that the mammalian brain has an intrinsic capacity to adapt to low oxygen which would improve outcome from a reversible hypoxic/ischemic episode. Acclimation to chronic hypoxia causes increased capillarity and tissue oxygen levels which may improve the capacity to survive ischemia. Identification of these adaptations will lead to protocols which high risk groups could use to improve recovery and reduce costs.

Methods and Findings

Rats were exposed to hypoxia (3 weeks living at ½ an atmosphere). After acclimation, capillary density was measured morphometrically and was increased by 30% in the cortex. Novel implantable oxygen sensors showed that partial pressure of oxygen in the brain was increased by 40% in the normal cortex. Infarcts were induced in brain with 1 h reversible middle cerebral artery occlusions. After ischemia (48 h) behavioural scores were improved and T2 weighted MRI lesion volumes were reduced by 52% in acclimated groups. There was a reduction in inflammation indicated by reduced lymphocytes (by 27–33%), and ED1 positive cells (by 35–45%).

Conclusions

It is possible to stimulate a natural adaptive mechanism in the brain which will reduce damage and improve outcome for a given ischemic event. Since these adaptations occur after factors such as HIF-1α have returned to baseline, protection is likely related more to morphological changes such as angiogenesis. Such pre-conditioning, perhaps with exercise or pharmaceuticals, would not necessarily reduce the incidence of stroke, but the severity of damage could be reduced by 50%.     

Effect of CDP-choline on the biosynthesis of nucleic acids and proteins in brain regions during hypoxia

The effect of CDP-choline on the in vivo incorporation of labeled precursors into DNA, RNA, and proteins in cerebral hemispheres, cerebellum, and brainstem of guinea pigs after hypoxic treatment was studied. The labeling of macromolecules extracted from the various subcellular fractions of these brain regions was also determined. Hypoxic treatment affected macromolecular labeling to a different extent in the three brain regions examined. CDP-choline treatment was not able to reverse the effect of hypoxia on DNA labeling, but it was able to remove the effect of hypoxia on RNA and protein labeling. The action of CDP-choline was particularly evident on the labeling of RNA in nuclei and mitochondria of the cerebellum and on the labeling of proteins in microsomes of the three brain regions examined.     

Basic Fibroblast Growth Factor Contributes to a Shift in the Angioregulatory Activity of Retinal Glial (Müller) Cells

Basic fibroblast growth factor (bFGF) is a pleiotropic cytokine with pro-angiogenic and neurotrophic effects. The angioregulatory role of this molecule may become especially significant in retinal neovascularization, which is a hallmark of a number of ischemic eye diseases. This study was undertaken to reveal expression characteristics of bFGF, produced by retinal glial (Müller) cells, and to determine conditions under which glial bFGF may stimulate the proliferation of retinal microvascular endothelial cells. Immunofluorescence labeling detected bFGF in Müller cells of the rat retina and in acutely isolated Müller cells with bFGF levels, which increased after ischemia-reperfusion in postischemic retinas. In patients with proliferative diabetic retinopathy or myopia, the immunoreactivity of bFGF co-localized to glial fibrillary acidic protein (GFAP)-positive cells in surgically excised retinal tissues. RT-PCR and ELISA analyses indicated that cultured Müller cells produce bFGF, which is elevated under hypoxia or oxidative stress, as well as under stimulation with various growth factors and cytokines, including pro-inflammatory factors. When retinal endothelial cells were cultured in the presence of media from hypoxia (0.2%)-conditioned Müller cells, a distinct picture of endothelial cell proliferation emerged. Media from 24-h cultured Müller cells inhibited proliferation, whereas 72-h conditioned media elicited a stimulatory effect. BFGF-neutralizing antibodies suppressed the enhanced endothelial cell proliferation to a similar extent as anti-VEGF antibodies. Furthermore, phosphorylation of extracellular signal-regulated kinases (ERK−1/−2) in retinal endothelial cells was increased when the cells were cultured in 72-h conditioned media, while neutralizing bFGF attenuated the activation of this signaling pathway. These data provide evidence that retinal (glial) Müller cells are major sources of bFGF in the ischemic retina. Müller cells under physiological conditions or transient hypoxia seem to provide an anti-angiogenic environment, but long-lasting hypoxia causes the release of bFGF, which might significantly co-stimulate neovascularization in the retina.     

Hypoxia Enhances Proliferation of Human Adipose-Derived Stem Cells via HIF-1ɑ Activation

BackgroundAdipose tissue-derived stem cells (ASCs) have been recently isolated from human subcutaneous adipose tissue. ASCs may be useful in regenerative medicine as an alternative to bone marrow-derived stem cells. Changes in the oxygen concentration influence physiological activities, such as stem cell proliferation. However, the effects of the oxygen concentration on ASCs remain unclear. In the present study, the effects of hypoxia on ASC proliferation were examined.MethodsNormal human adipose tissue was collected from the lower abdomen, and ASCs were prepared with collagenase treatment. The ASCs were cultured in hypoxic (1%) or normoxic (20%) conditions. Cell proliferation was investigated in the presence or absence of inhibitors of various potentially important kinases. Hypoxia inducible factor (HIF)-1α expression and MAP kinase phosphorylation in the hypoxic culture were determined with western blotting. In addition, the mRNA expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)-2 in hypoxic or normoxic conditions were determined with real-time RT-PCR. The effects of these growth factors on ASC proliferation were investigated. Chromatin immunoprecipitation (ChIP) of the HIF–1α-binding hypoxia responsive element in FGF–2 was performed. HIF–1α was knocked down by siRNA, and FGF–2 expression was investigated.ResultsASC proliferation was significantly enhanced in the hypoxic culture and was inhibited by ERK and Akt inhibitors. Hypoxia for 5–15 minutes stimulated the phosphorylation of ERK1/2 among MAP kinases and induced HIF–1α expression. The levels of VEGF and FGF–2 mRNA and protein in the ASCs were significantly enhanced in hypoxia, and FGF–2 increased ASC proliferation. The ChIP assay revealed an 8-fold increase in the binding of HIF–1α to FGF–2 in hypoxia. HIF–1α knockdown by siRNA partially inhibited the FGF–2 expression of ASCs induced by hypoxia.ConclusionASC proliferation was enhanced by hypoxia. HIF–1α activation, FGF–2 production, and the ERK1/2 and Akt pathway were involved in this regulatory mechanism.     

Short-term Hypoxia Increases Tyrosine Hydroxylase Immunoreactivity in Rat Carotid Body

Neurochemical and morphological changes in the carotid body are induced by chronic hypoxia, leading to regulation of ventilation. In this study, we examined the time courses of changes in immunohistochemical intensity for tyrosine hydroxylase (TH) and cellular volume of glomus cells in rats exposed to hypoxia (10% O₂) for up to 24 hr. Grayscale intensity for TH immunofluorescence was significantly increased in rats exposed to hypoxia for 12, 18, and 24 hr compared with control rats (p<0.05). The transectional area of glomus cells was not significantly different between experimental groups. The TH fluorescence intensity of the glomus cells exhibited a strong negative correlation with the transectional area in control rats (Spearman''s ρ = −0.70). This correlation coefficient decreased with exposure time, and it was lowest for the rats exposed to hypoxia for 18 hr (ρ = −0.18). The histogram of TH fluorescence intensity showed a single peak in control rats. The peaks were gradually shifted to the right and became less pronounced in hypoxia-exposed rats, suggesting that a hypoxia-induced increase in TH immunoreactivity occurred uniformly in glomus cells. In conclusion, this study demonstrates that short-term hypoxia induces an increase in TH protein expression in rat carotid body glomus cells. (J Histochem Cytochem 58:839–846, 2010)     

Relationship between Concentrations of Lutein and StARD3 among Pediatric and Geriatric Human Brain Tissue

Lutein, a dietary carotenoid, selectively accumulates in human retina and brain. While many epidemiological studies show evidence of a relationship between lutein status and cognitive health, lutein’s selective uptake in human brain tissue and its potential function in early neural development and cognitive health have been poorly evaluated at a molecular level. The objective of this study was to evaluate the cross-sectional relationship between concentrations of brain lutein and StARD3 (identified as its binding protein in retinal tissue) among three age groups: infants (1–4 months, n = 10), older adults (55–86 years, n = 8), and centenarians (98–105 years, n = 10). Brain lutein concentrations were analyzed by high-performance liquid chromatography and StARD3 levels were analyzed by Western Blot analysis. The strong relationship in infant brains (r = 0.75, P < 0.001) suggests that lutein has a role in neural development. The relationship remained significant but weaker in older adults (r = 0.51, P < 0.05) and insignificant in centenarians (r = 0.08, P > 0.05), seven of whom had mild cognitive impairment (MCI) or dementia. These exploratory findings suggest an age-related decrease or abnormality of StARD3 activity in human brain. Given that StARD3 is also involved in cholesterol transportation, a process that is aberrant in neurodegenerative diseases, the potential protective function of lutein against these diseases remains to be explored.     

The Potential Association between Obstructive Sleep Apnea and Diabetic Retinopathy in Severe Obesity—The Role of Hypoxemia

Background

Obstructive sleep apnea (OSA) is common in obese patients with type 2 diabetes mellitus (DM) and may contribute to diabetic microvascular complications.

Methods

To investigate the association between OSA, hypoxemia during sleep, and diabetic retinal complications in severe obesity. This was a prospective observational study of 93 obese patients mean (SD) age: 52(10) years; mean (SD) body mass index (BMI): 47.3(8.3) kg/m²) with DM undergoing retinal screening and respiratory monitoring during sleep. OSA was defined as apnea-hypopnea index (AHI) of ≥15 events/hour, resulting in two groups (OSA+ vs. OSA−).

Results

Forty-six patients were OSA+: median (95% CI) AHI = 37(23–74)/hour and 47 were OSA–ve (AHI = 7(4–11)/hour). Both groups were similar for ethnicity, BMI, cardiovascular co-morbidities, diabetes duration, HbA_1c, and insulin treatment (p>0.05). The OSA+ group was significantly more hypoxemic. There was no significant difference between OSA+ and OSA− groups for the presence of retinopathy (39% vs. 38%). More OSA+ subjects had maculopathy (22% vs. 13%), but this did not reach statistical significance. Logistic regression analyses showed that AHI was not significantly associated with the presence of retinopathy or maculopathy (p>0.05). Whilst minimum oxygen saturation was not significantly associated with retinopathy, it was an independent predictor for the presence of maculopathy OR = 0.79 (95% CI: 0.65–0.95; p<0.05), after adjustment.

Conclusions

The presence of OSA, as determined by AHI, was not associated with diabetic retinal complications. In contrast, severity of hypoxemia during sleep (minimum oxygen saturations) may be an important factor. The importance of hypoxia in the development of retinal complications in patients with OSA remains unclear and further studies assessing the pathogenesis of hypoxemia in patients with OSA and diabetic retinal disease are warranted.     

Crowdsourcing as a Novel Technique for Retinal Fundus Photography Classification: Analysis of Images in the EPIC Norfolk Cohort on Behalf of the UKBiobank Eye and Vision Consortium

Aim

Crowdsourcing is the process of outsourcing numerous tasks to many untrained individuals. Our aim was to assess the performance and repeatability of crowdsourcing for the classification of retinal fundus photography.

Methods

One hundred retinal fundus photograph images with pre-determined disease criteria were selected by experts from a large cohort study. After reading brief instructions and an example classification, we requested that knowledge workers (KWs) from a crowdsourcing platform classified each image as normal or abnormal with grades of severity. Each image was classified 20 times by different KWs. Four study designs were examined to assess the effect of varying incentive and KW experience in classification accuracy. All study designs were conducted twice to examine repeatability. Performance was assessed by comparing the sensitivity, specificity and area under the receiver operating characteristic curve (AUC).

Results

Without restriction on eligible participants, two thousand classifications of 100 images were received in under 24 hours at minimal cost. In trial 1 all study designs had an AUC (95%CI) of 0.701(0.680–0.721) or greater for classification of normal/abnormal. In trial 1, the highest AUC (95%CI) for normal/abnormal classification was 0.757 (0.738–0.776) for KWs with moderate experience. Comparable results were observed in trial 2. In trial 1, between 64–86% of any abnormal image was correctly classified by over half of all KWs. In trial 2, this ranged between 74–97%. Sensitivity was ≥96% for normal versus severely abnormal detections across all trials. Sensitivity for normal versus mildly abnormal varied between 61–79% across trials.

Conclusions

With minimal training, crowdsourcing represents an accurate, rapid and cost-effective method of retinal image analysis which demonstrates good repeatability. Larger studies with more comprehensive participant training are needed to explore the utility of this compelling technique in large scale medical image analysis.     

Association between Retinal Arteriolar and Venule Calibre with Prevalent Heart Failure: A Cross-Sectional Study

Background

There is evidence to suggest that microvascular disease, particularly diabetic retinopathy, plays a role in the pathogenesis of HF. However, whether changes in retinal vessel calibre predicts HF is unclear. The purpose of this study was to examine the association of retinal microvascular structure with prevalent heart failure (HF).

Methods

The Australian Heart Eye Study (AHES) is a cross-sectional study that surveyed 1680 participants who presented to a tertiary referral hospital for the evaluation of potential coronary artery disease by coronary angiography. Retinal vessel calibre was graded using retinal photography and participants’ self-reported echocardiography-confirmed HF was obtained via an extensive medical questionnaire.

Results

There were 107 participants (8.1%) with prevalent self-reported HF. Persons with wider retinal arteriolar calibre (comparing highest versus lowest tertile or reference) were more likely to have prevalent HF (OR 3.5; 95% CI, 1.7–7.2) when adjusted for age and sex. After further adjustment for body mass index, hypertension, diabetes, smoking status, triglycerides and estimated glomerular filtration rate, this association remained significant (OR 4.5; 95% CI, 2.0–9.8). After further stratification, this association remained significant among participants with diabetes (OR 10.3; 95% CI, 2.7–39.3) but not in those without diabetes (OR 2.7; 95% CI, 0.9–7.5). The strength of this association was not dependent on the length of history of diabetes, or retinopathy status. There was no significant association between retinal venular calibre and prevalence of HF.

Conclusions

Wider retinal arteriolar diameter was significantly and independently associated with prevalent HF in participants of a cross-sectional study. This association was significant stronger among participants with diabetes compared to without diabetes. No association was found between retinal venule calibre with prevalent HF.     

Altered Resting State Brain Dynamics in Temporal Lobe Epilepsy Can Be Observed in Spectral Power,Functional Connectivity and Graph Theory Metrics

Despite a wealth of EEG epilepsy data that accumulated for over half a century, our ability to understand brain dynamics associated with epilepsy remains limited. Using EEG data from 15 controls and 9 left temporal lobe epilepsy (LTLE) patients, in this study we characterize how the dynamics of the healthy brain differ from the “dynamically balanced” state of the brain of epilepsy patients treated with anti-epileptic drugs in the context of resting state. We show that such differences can be observed in band power, synchronization and network measures, as well as deviations from the small world network (SWN) architecture of the healthy brain. The θ (4–7 Hz) and high α (10–13 Hz) bands showed the biggest deviations from healthy controls across various measures. In particular, patients demonstrated significantly higher power and synchronization than controls in the θ band, but lower synchronization and power in the high α band. Furthermore, differences between controls and patients in graph theory metrics revealed deviations from a SWN architecture. In the θ band epilepsy patients showed deviations toward an orderly network, while in the high α band they deviated toward a random network. These findings show that, despite the focal nature of LTLE, the epileptic brain differs in its global network characteristics from the healthy brain. To our knowledge, this is the only study to encompass power, connectivity and graph theory metrics to investigate the reorganization of resting state functional networks in LTLE patients.     

Effect of exogenous CDP-choline on choline metabolism in isolated adult rat ventricular myocytes under normoxic and hypoxic conditions

The purpose of this study was to examine the effect of exogenous CDP-choline on choline metabolism and phosphatidylcholine biosynthesis in adult rat ventricular myocytes. Choline uptake and metabolism were examined, using [methyl³ H] choline. CDP-choline in the medium produced a concentration dependent reduction in the amount of radio-label in phosphocholine and phospholipid but it did not alter choline uptake into the myocytes. CDP-choline also did not antagonize the effect of hypoxia on phosphatidylcholine synthesis; rather it accentuated the hypoxia-induced reductions in cellular phosphocholine and phosphatidylcholine biosynthesis. These results indicate that the exogenous administration of CDP-choline alters choline metabolism in the heart by reducing the formation of phosphocholine and phosphatidylcholine without altering choline uptake and suggest an effect of a CDP-choline metabolite on choline metabolism which is not effective in opposing the effect of hypoxia on phosphatidylcholine biosynthesis.     

Directional Connectivity between Frontal and Posterior Brain Regions Is Altered with Increasing Concentrations of Propofol

Recent studies using electroencephalography (EEG) suggest that alteration of coherent activity between the anterior and posterior brain regions might be used as a neurophysiologic correlate of anesthetic-induced unconsciousness. One way to assess causal relationships between brain regions is given by renormalized partial directed coherence (rPDC). Importantly, directional connectivity is evaluated in the frequency domain by taking into account the whole multichannel EEG, as opposed to time domain or two channel approaches. rPDC was applied here in order to investigate propofol induced changes in causal connectivity between four states of consciousness: awake (AWA), deep sedation (SED), loss (LOC) and return of consciousness (ROC) by gathering full 10/20 system human EEG data in ten healthy male subjects. The target-controlled drug infusion was started at low rate with subsequent gradual stepwise increases at 10 min intervals in order to carefully approach LOC (defined as loss of motor responsiveness to a verbal stimulus). The direction of the causal EEG-network connections clearly changed from AWA to SED and LOC. Propofol induced a decrease (p = 0.002–0.004) in occipital-to-frontal rPDC of 8-16 Hz EEG activity and an increase (p = 0.001–0.040) in frontal-to-occipital rPDC of 10–20 Hz activity on both sides of the brain during SED and LOC. In addition, frontal-to-parietal rPDC within 1–12 Hz increased in the left hemisphere at LOC compared to AWA (p = 0.003). However, no significant changes were detected between the SED and the LOC states. The observed decrease in back-to-front EEG connectivity appears compatible with impaired information flow from the posterior sensory and association cortices to the executive prefrontal areas, possibly related to decreased ability to perceive the surrounding world during sedation. The observed increase in the opposite (front-to-back) connectivity suggests a propofol concentration dependent association and is not directly related to the level of consciousness per se.     

A mechanism for suppression of the CDP-choline pathway during apoptosis

Inhibition of the CDP-choline pathway during apoptosis restricts the availability of phosphatidylcholine (PtdCho) for assembly of membranes and synthesis of signaling factors. The N-terminal nuclear localization signal (NLS) in CTP:phosphocholine cytidylyltransferase (CCT)α is removed during apoptosis but the caspase(s) involved and the contribution to suppression of the CDP-choline pathway is unresolved. In this study we utilized siRNA silencing of caspases in HEK293 cells and caspase 3-deficient MCF7 cells to show that caspase 3 is required for CCTα proteolysis and release from the nucleus during apoptosis. CCTα-Δ28 (a caspase-cleaved mimic) expressed in CCTα-deficient Chinese hamster ovary cells was cytosolic and had increased in vitro activity. However, [³H]choline labeling experiments in camptothecin-treated MCF7 cells and MCF7 cells expressing caspase 3 (MCF7-C3) revealed a global suppression of the CDP-choline pathway that was consistent with inhibition of a step prior to CCTα. In camptothecin-treated MCF7 and MCF7-C3 cells, choline kinase activity was unaffected; however, choline transport into cells was reduced by 30 and 60%, respectively. We conclude that caspase 3-mediated removal of the CCTα NLS contributes minimally to the inhibition of PtdCho synthesis during DNA damage-induced apoptosis. Rather, the CDP-choline pathway is inhibited by caspase 3-independent and -dependent suppression of choline transport into cells.     

The Value of Long-Term Stream Invertebrate Data Collected by Citizen Scientists

The purpose of this investigation was to systematically examine the variability associated with temporally-oriented invertebrate data collected by citizen scientists and consider the value of such data for use in stream management. Variability in invertebrate data was estimated for three sources of variation: sampling, within-reach spatial and long-term temporal. Long-term temporal data were also evaluated using ordinations and an Index of Biotic Integrity (IBI). Through two separate investigations over an 11-year study period, participants collected more than 400 within-reach samples during 44 sampling events at three streams in the western United States. Within-reach invertebrate abundance coefficient of variation (CV) ranged from 0.44–0.50 with approximately 62% of the observed variation strictly due to sampling. Long-term temporal CV ranged from 0.31–0.36 with 27–30% of the observed variation in invertebrate abundance related to climate conditions (El Niño strength) and sampling year. Ordinations showed that citizen-generated assemblage data could reliably detect differences between study streams and seasons. IBI scores were significantly different between streams but not seasons. The findings of this study suggest that citizen data would likely detect a change in mean invertebrate density greater than 50% and would also be useful for monitoring changes in assemblage. The information presented here will help stream managers interpret and evaluate changes to the stream invertebrate community detected by citizen-based programs.     

Retinal Microvascular Abnormalities and Risk of Renal Failure in Asian Populations

BackgroundRetinal microvascular signs may provide insights into the structure and function of small vessels that are associated with renal disease. We examined the relationship of retinal microvascular signs with both prevalent and incident end-stage renal disease (ESRD) in a multi-ethnic Asian population.MethodsA total of 5763 subjects (aged ≥40 years) from two prospective population-based studies (the Singapore Malay Eye Study and the Singapore Prospective Study) were included for the current analysis. Retinopathy was graded using the modified Airlie House classification system. Retinal vascular parameters were measured using computer-assisted programs to quantify the retinal vessel widths (arteriolar and venular caliber) and retinal vascular network (fractal dimension). Data on ESRD was obtained by record linkage with the ESRD cases registered by National Registry of Diseases Office, Singapore. Multi-variable adjusted regression analyses were performed to assess the associations of baseline retinal vascular parameters and prevalent and incident ESRD.ResultsAt baseline, 21(0.36%) persons had prevalent ESRD. During a median follow-up of 4.3 years, 33 (0.57%) subjects developed ESRD. In our analyses, retinopathy was associated with prevalent ESRD (multi-variable adjusted odds ratio [OR], 3.21, 95% confidence interval [CI]: 1.28–8.05) and incident ESRD (multi-variable adjusted hazard ratio [HR], 2.51, 95%CI: 1.14–5.54). This association was largely seen in person with diabetes (HR, 2.60, 95%CI: 1.01–6.66) and not present in persons without diabetes (HR, 1.65, 95%CI: 0.14–18.98). Retinal arteriolar caliber, retinal venular caliber and retinal vascular fractal dimension were not associated with ESRD.ConclusionRetinopathy signs in persons with diabetes are related to an increased risk of ESRD; however, other microvascular changes in the retina are not associated with ESRD.