Kidney and eye diseases: common risk factors, etiological mechanisms, and pathways. Kidney Int. 2014;85:1290-1302. [PMID: 24336029 DOI: 10.1038/ki.2013.491]

Correlations between choroidal thickness and renal function in patients with retinal vein occlusion

The purpose of this study was to analyze the correlation of renal function indices with sub-foveal choroidal thickness (SFChT) in treatment-naïve (naïve) eyes with retinal vein occlusion (RVO) using swept-source optical coherence tomography (SS-OCT) and systemic workup. Retrospective chart review was performed from Dec 2016 to Sep 2019 in patients newly diagnosed with treatment-naïve unilateral RVO. Ocular parameters, including SFChT, and systemic profiles, including renal function indices, were reviewed. Simple and multiple linear regression analyses were performed to check if there was a correlation between renal profiles and SFChT. A total of 56 patients were included in the study; 34 of them were branch RVO and 22 were central RVO patients. Multiple linear regression analysis revealed that SFChT was positively correlated with estimated glomerular filtration rate (eGFR) (P < 0.001). SFChT showed significant correlation with renal function indices. In addition, choroidal thickness may be considered as systemic biomarkers for renal function.

Association of retinal venular tortuosity with impaired renal function in the Northern Ireland Cohort for the Longitudinal Study of Ageing

BACKGROUND

Previous studies have identified retinal microvascular features associated with renal dysfunction. Biopsies are necessary to confirm kidney microvascular damage and retinal imaging may enable evaluation of microangiopathic characteristics reflecting renal changes associated with chronic kidney disease (CKD). We evaluated retinal microvascular parameters (RMPs) for associations with renal function in a cross-sectional analysis of the Northern Ireland Cohort for the Longitudinal Study of Ageing.

METHODS

RMPs (central retinal arteriolar/ venular equivalents [CRAE/CRVE], arteriolar to venular ratio [AVR], fractal dimension and tortuosity) were measured from optic disc centred fundus images using semi-automated software. Associations were assessed with multivariable regression analyses between RMPs and estimated glomerular filtration rate (eGFR) defined by serum creatinine (eGFRscr) and cystatin C (eGFRcys) and also CKD status characterised by eGFR < 60 mL/min/1.73m2. Regression models were adjusted for potential confounders including age, sex, diabetes, smoking status, educational attainment, cardiovascular disease, body mass index, antihypertensive medication, systolic blood pressure, triglycerides, high- and low-density lipoprotein levels.

RESULTS

Data were included for 1860 participants that had measures of renal function and retinal fundus images of sufficient quality for analysis. Participants had a mean age of 62.0 ± 8.5 yrs. and 53% were female. The mean eGFR for scr and cys were 82.2 ± 14.9 mL/min/1.73m2 and 70.7 ± 18.6 mL/min/1.73m2 respectively. eGFRcys provided lower estimates than eGFRscr resulting in a greater proportion of participants categorised as having CKD stages 3-5 (eGFRcys 26.8%; eGFRscr 7.9%). Multivariable regression analyses showed that increased venular tortuosity (OR = 1.30; 95%CI: 1.10, 1.54; P < 0.01) was associated with CKD stages 3-5 characterised by eGFRscr < 60 mL/min/1.73 m2. No additional associations between CKD status characterised by eGFRscr or with eGFRcys, were detected (P > 0.05). Multivariable regression failed to detect associations between CRAE, CRVE, AVR, fractal dimension or tortuosity and eGFRscr or eGFRcys (P > 0.05).

CONCLUSION

Increased retinal venular tortuosity was associated with CKD stages 3-5 defined by eGFRscr < 60 mL/min/1.73 m2, in an older population independent of potential confounding factors. These retinal measures may provide non-invasive microvascular assessment of associations with CKD.

Plasma phenylalanine and tyrosine and their interactions with diabetic nephropathy for risk of diabetic retinopathy in type 2 diabetes

OBJECTIVE

Tight control of hyperglycemia reduces risk of diabetic retinopathy (DR), but the residual risk remains high. This study aimed to explore relationships between plasma phenylalanine and tyrosine with DR in type 2 diabetes (T2D) and interactions between the two amino acids, and their secondary interaction with renal dysfunction.

RESEARCH DESIGN AND METHODS

We extracted data of 1032 patients with T2D from tertiary hospital consecutively from May 2015 to August 2016. Binary logistic regression models with restricted cubic spline were used to check potential non-linear associations and to obtain ORs and 95% CIs of variables under study. Addictive interaction was estimated using relative excess risk due to interaction, attributable proportion due to interaction and synergy index. Area under the receiver operating characteristic curve was used to check increased predictive values.

RESULTS

Of 1032 patients, 162 suffered from DR. Copresence of low phenylalanine and low tyrosine increased DR risk (OR 6.01, 95% CI 1.35 to 26.8), while either of them alone did not have a significant effect with significant additive interaction. Presence of diabetic nephropathy further increased the OR of copresence of low phenylalanine and low tyrosine for DR to 25.9 (95% CI 8.71 to 76.9) with a significant additive interaction. Inclusion of phenylalanine and tyrosine in a traditional risk factor model significantly increased area under the curve from 0.81 to 0.83 (95% CI 0.80 to 0.86).

CONCLUSION

Plasma low phenylalanine and low tyrosine worked independently and synergistically to increase the risk of DR in T2D. Presence of renal dysfunction further amplified the effect of copresence of low phenylalanine and low tyrosine on DR risk.

Impact of blood pressure control on retinal microvasculature in patients with chronic kidney disease

Chronic kidney disease (CKD) is an emerging disease worldwide. We investigated the relationship between blood pressure (BP) control and parafoveal retinal microvascular changes in patients with CKD. This case–control study enrolled 256 patients with CKD (stage 3–5) and 70 age‐matched healthy controls. Optical coherence tomography angiography showed lower superficial vascular plexus (SVP) vessel density, lower deep vascular plexus (DVP) vessel density, and larger SVP flow void area in the CKD group. The BP parameters at enrollment and during the year before enrollment were collected in patients with CKD. Partial correlation was used to determine the relationship between BP parameters and microvascular parameters after controlling for age, sex, diabetes mellitus, axial length, and intraocular pressure. The maximum systolic blood pressure (SBP) (p = 0.003) and within-patient standard deviation (SD) of SBP (p = 0.006) in 1 year were negatively correlated with SVP vessel density. The average SBP (p = 0.040), maximum SBP (p = 0.001), within-patient SD of SBP (p < 0.001) and proportion of high BP measurement (p = 0.011) in 1 year were positively correlated with the SVP flow void area. We concluded that long-term SBP was correlated with SVP microvascular injury in patients with CKD. Superficial retinal microvascular changes may be a potential biomarker for prior long-term BP control in these patients.

The eye, the kidney, and cardiovascular disease: old concepts, better tools, and new horizons

Chronic kidney disease (CKD) is common, with hypertension and diabetes mellitus acting as major risk factors for its development. Cardiovascular disease is the leading cause of death worldwide and the most frequent end point of CKD. There is an urgent need for more precise methods to identify patients at risk of CKD and cardiovascular disease. Alterations in microvascular structure and function contribute to the development of hypertension, diabetes, CKD, and their associated cardiovascular disease. Homology between the eye and the kidney suggests that noninvasive imaging of the retinal vessels can detect these microvascular alterations to improve targeting of at-risk patients. Retinal vessel-derived metrics predict incident hypertension, diabetes, CKD, and cardiovascular disease and add to the current renal and cardiovascular risk stratification tools. The advent of optical coherence tomography (OCT) has transformed retinal imaging by capturing the chorioretinal microcirculation and its dependent tissue with near-histological resolution. In hypertension, diabetes, and CKD, OCT has revealed vessel remodeling and chorioretinal thinning. Clinical and preclinical OCT has linked retinal microvascular pathology to circulating and histological markers of injury in the kidney. The advent of OCT angiography allows contrast-free visualization of intraretinal capillary networks to potentially detect early incipient microvascular disease. Combining OCT's deep imaging with the analytical power of deep learning represents the next frontier in defining what the eye can reveal about the kidney and broader cardiovascular health.

Primary Open-angle Glaucoma and Increased Risk of Chronic Kidney Disease

PRECIS

The association between primary open-angle glaucoma (POAG) and subsequent development of chronic kidney disease (CKD) was investigated using a nationwide, population-based, retrospective cohort in South Korea. POAG increases the risk of subsequent CKD development.

PURPOSE

The purpose of this study was to investigate the risk of subsequent CKD development in patients with POAG.

METHODS

In this nationwide, population-based longitudinal cohort, 1,025,340 beneficiaries in the 2002-2013 Korean National Health Insurance database were included. We identified patients with incident POAG and evaluated the risk of subsequent CKD development using diagnostic codes from the database after 2-year wash-out periods. We applied time-varying covariate Cox regression analyses to determine the effect of POAG on the development of CKD: Model 1 included only POAG as a time-varying covariate; Model 2 included Model 1 and demographic information; and Model 3 included Model 2, comorbidity, comedication, and the Charlson Comorbidity Index score.

RESULTS

The fixed cohort included 478,303 eligible subjects, and of these subjects, 1749 suffered incident POAG, and 3157 developed CKD. POAG was associated with an increased risk of CKD development [hazard ratio (HR)=7.63; 95% confidence interval (CI), 5.89-9.87] in Model 1; HR=3.54 (95% CI, 2.73-4.58) in Model 2; and HR=2.90 (95% CI, 2.24-3.76) in Model 3].

CONCLUSION

POAG increased the risk of subsequent CKD in the general population, suggesting that POAG and CKD might share a common pathogenic mechanism.

Assessment of Retinal Microangiopathy in Chronic Kidney Disease Patients

INTRODUCTION

Optical coherence tomography angiography (OCT-A) is a useful diagnostic tool for assessing eyes' health in patients with chronic diseases, such as diabetes, hypertension, Parkinson's disease and chronic kidney disease (CKD).

AIM

To detect changes in macular structure and retinal vascular meshwork in the macular area and peripapillary in patients with chronic kidney disease (CKD).

METHODS

This cross-sectional study included 80 eyes of patients with CKD in stages 2, 3 or 4, who were followed-up in the Nephrology Clinic of University Clinical Center Sarajevo. All patients were categorized according to the stage of CKD. All patients were scanned by a high-speed 840-nm-wavelength spectral-domain optical coherence tomography instrument (RTVue XR Avanti; Optovue, Inc, Fremont, California, USA). Blood flow was detected using a split-spectrum amplitude-decorrelation angiography algorithm. A fully automated microstructural analysis of the foveal avascular zone (FAZ), FAZ perimeter, foveal vessel density in a 300-μm area around the FAZ (FD), nonflow area, flow index in superficial and deep vascular plexus, choriocapillary flow, vascular density, radial peripapillary capillary density was performed.

RESULTS

When comparing patients with CKD stage 2 and stage 3 there were no statistically significant changes in microvascular parameters on OCT angiography, as well as when comparing patients with CKD stage 3 and stage 4. But in the comparison between patients with less developed CKD (stage 2) and terminal CKD (stage 4) there was a significant difference between some microvascular parameters such as FAZ area, FAZ perimeter, choriocapillary flow.

CONCLUSION

Many studies demonstrated that evaluation of the microvascular changes in different retinal layers using SS-OCTA may be considered as a key to assessing the systemic perfusion status. Evaluation of retinal microvasculature may ease the management and approach of patients with CKD, having in mind that the retinal and the kidney vascular network are, concerning structure, development and the function, very similar.

A deep learning algorithm to detect chronic kidney disease from retinal photographs in community-based populations

BACKGROUND

Screening for chronic kidney disease is a challenge in community and primary care settings, even in high-income countries. We developed an artificial intelligence deep learning algorithm (DLA) to detect chronic kidney disease from retinal images, which could add to existing chronic kidney disease screening strategies.

METHODS

We used data from three population-based, multiethnic, cross-sectional studies in Singapore and China. The Singapore Epidemiology of Eye Diseases study (SEED, patients aged ≥40 years) was used to develop (5188 patients) and validate (1297 patients) the DLA. External testing was done on two independent datasets: the Singapore Prospective Study Program (SP2, 3735 patients aged ≥25 years) and the Beijing Eye Study (BES, 1538 patients aged ≥40 years). Chronic kidney disease was defined as estimated glomerular filtration rate less than 60 mL/min per 1·73m². Three models were trained: 1) image DLA; 2) risk factors (RF) including age, sex, ethnicity, diabetes, and hypertension; and 3) hybrid DLA combining image and RF. Model performances were evaluated using the area under the receiver operating characteristic curve (AUC).

FINDINGS

In the SEED validation dataset, the AUC was 0·911 for image DLA (95% CI 0·886 -0·936), 0·916 for RF (0·891-0·941), and 0·938 for hybrid DLA (0·917-0·959). Corresponding estimates in the SP2 testing dataset were 0·733 for image DLA (95% CI 0·696-0·770), 0·829 for RF (0·797-0·861), and 0·810 for hybrid DLA (0·776-0·844); and in the BES testing dataset estimates were 0·835 for image DLA (0·767-0·903), 0·887 for RF (0·828-0·946), and 0·858 for hybrid DLA (0·794-0·922). AUC estimates were similar in subgroups of people with diabetes (image DLA 0·889 [95% CI 0·850-0·928], RF 0·899 [0·862-0·936], hybrid 0·925 [0·893-0·957]) and hypertension (image DLA 0·889 [95% CI 0·860-0·918], RF 0·889 [0·860-0·918], hybrid 0·918 [0·893-0·943]).

INTERPRETATION

A retinal image DLA shows good performance for estimating chronic kidney disease, underlying the feasibility of using retinal photography as an adjunctive or opportunistic screening tool for chronic kidney disease in community populations.

FUNDING

National Medical Research Council, Singapore.

Visual Impairment and Major Eye Diseases in Chronic Kidney Disease: The National Health and Nutrition Examination Survey, 2005-2008

PURPOSE

To investigate the prevalence and associations of visual impairment (VI) and major eye diseases with chronic kidney disease (CKD) in the United States.

DESIGN

Cross-sectional study.

METHODS

We investigated the prevalence and associations of VI and major eye diseases with CKD among 5,518 participants aged 40 years or older in the 2005-2008 National Health and Nutrition Examination Survey. An estimated glomerular filtration rate of lower than 60 mL/min/1.73 m² was defined as CKD. Corrected visual acuity of worse than 20/40 in the better-seeing eye was defined as VI. Major eye diseases, including any ocular disease, any objectively determined ocular disease, cataract surgery, any retinopathy, diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma were evaluated from questionnaire or retinal photographs using standardized grading protocols.

RESULTS

The prevalence of VI and major eye diseases were approximately 2- to 7-fold higher in participants with CKD than in those without (all P < .05). After controlling for multiple confounders, the presence of CKD was associated with VI (odds ratio [OR]: 2.01, 95% confidence interval [CI]: 1.14-3.54), any ocular disease (OR: 1.65, 95% CI: 1.22-2.22), any objectively determined ocular disease (OR: 1.52, 95% CI: 1.06-2.19), any retinopathy (OR: 1.70, 95% CI: 1.18-2.45), and DR (OR: 2.34, 95% CI: 1.23-4.42). There was no association of CKD with cataract surgery, AMD, or glaucoma. A significant association between CKD and any ocular disease was observed among nondiabetic participants. The presence of CKD was closely related to VI and any retinopathy among diabetic participants.

CONCLUSIONS

This nationally representative sample of the US population demonstrated high prevalence and strong associations of VI and major eye diseases with CKD, highlighting the importance of ocular screening among CKD patients and potential common pathogenesis underlying these conditions.

Correlation between Renal Function and Peripapillary Choroidal Thickness in Treatment-Naïve Diabetic Eyes Using Swept-Source Optical Coherence Tomography

Purpose: To investigate the associations of the estimated glomerular filtration rate (eGFR) with peripapillary choroidal thickness (pCT) and retinal nerve fiber layer (pRNFL) thickness in diabetic patients by using swept-source optical coherence tomography (SS-OCT). Methods: Ocular treatment-naïve patients with type 2 diabetes mellitus registered in the community health system in Guangzhou, China, were recruited to participate in this prospective cross-sectional study. The eGFR was determined using the Xiangya formula, and the renal function was categorized into non-chronic kidney disease (non-CKD), mild CKD, and moderate to severe CKD (MS-CKD) according to the guidelines. The pCT and pRNFL thicknesses at 12 o'clock were obtained using an SS-OCT by a circular scan with a diameter of 3.4 mm centering on the optic nerve head, and the data from only one eye in each patient were used. Results: This study included 1,408 diabetic patients, with a mean age of 64.4 ± 7.8 years. The average pCT decreased with renal function deterioration, with 126.0 ± 58.0 μm for non-CKD, 112.0 ± 51.2 μm for mild CKD and 71.0 ± 22.9 μm for MS-CKD, respectively (P < .001). The pCT was found to be significantly thinner in CKD patients in all quadrantes (P < .05 in all regions) with the exception of the inferior quadrant, and the average pCT was positively correlated with eGFR (β = 0.3, 95%CI = 0.0 to 0.6, P = .021) after adjusting for other factors. The pRNFL thickness in the nasal quadrant was significantly reduced in patients with CKD, and pRNFL thickness was positively correlated with eGFR (β = 0.1, 95%CI = 0.0-0.2, P = .009) after adjusting for other factors. Conclusion: Impaired renal function was associated with a reduction of pCT and pRNFL thickness in patients with type 2 diabetes. The measurement of pCT and pRNFL may provide additional information for predicting renal impairment.

Klotho Pathways, Myelination Disorders, Neurodegenerative Diseases, and Epigenetic Drugs

In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.

Association of renal function with retinal vessel density in patients with type 2 diabetes by using swept-source optical coherence tomographic angiography

AIMS

To investigate the relationship between retinal vessel density and renal function in patients with diabetes mellitus (DM) using non-invasive optical coherence tomographic angiography (OCTA).

METHODS

This prospective cross-sectional study recruited ocular-treatment-naïve patients with DM registered in the community of Guangzhou, China. The retinal vessel density of the superficial capillary plexus in the macula was obtained by using swept-source OCTA imaging. The Xiangya equation was used to calculate the estimated glomerular filtrate rate (eGFR). Participants were divided into the following groups by eGFR: no chronic kidney disease (non-CKD), mild CKD and moderate-to-severe CKD (MS-CKD).

RESULTS

A total of 874 patients with DM (874 eyes), with a mean age of 64.8±7.1 years, were included in the final analysis. The vessel density was significantly lower in patients with CKD than in non-CKD patients in a dose-response pattern, with a parafoveal vessel density of 49.1%±2.1% in non-CKD, 48.4%±1.9% in mild CKD and 47.2%±1.7% in MS-CKD (p<0.001). The sparser retinal capillaries were related to lower eGFR (β=0.037; 95% CI 0.025 to 0.049; p<0.001) and higher microalbuminuria (β = -0.023; 95% CI -0.039 to -0.008; p=0.002). The eGRF was independently associated with parafoveal vessel density (β=0.029; 95% CI 0.016 to 0.042; p<0.001), even after adjusting for other factors.

CONCLUSION

Retinal vessel density decreased with renal function impairment, underlining the potential value of OCTA to detect early microvascular damage in the kidney in patients with diabetes.

Association Between Progression of Retinopathy and Concurrent Progression of Kidney Disease: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

Importance

Associations between retinopathy and kidney disease have been previously described. The association between the progression of retinopathy and concurrent progression of chronic kidney disease is unknown.

Objective

To assess the association between progression of retinopathy and concurrent progression of chronic kidney disease (CKD) among persons with CKD enrolled in a prospective cohort study.

Design, Setting, and Participants

A total of 1936 patients with chronic kidney disease enrolled in the multicenter, prospective Chronic Renal Insufficiency Cohort (CRIC) Study were invited to have 2 nonmydriatic fundus photography sessions separated by a mean (SD) of 3.5 (0.5) years. The study was conducted from May 12, 2006, to June 29, 2011. Data analysis was performed from March 16, 2016, to November 17, 2017.

Main Outcomes and Measures

Fundus photographs obtained at baseline and then at a follow-up at 3.5 years were reviewed by masked graders for presence and severity of retinopathy, and vessel calibers were assessed using standard protocols. The associations of the changes in retinal features with progression of CKD (50% estimated glomerular filtration rate [eGFR] loss or incident end-stage renal disease, and differences in eGFR slope in the same time period) were assessed with univariable and multivariable logistic regression models.

Results

Among 1583 CRIC participants who had baseline fundus photography, had additional follow-up in CRIC, and were at risk for retinopathy progression, 1025 patients (64.8%) had follow-up photography. The odds ratio (OR) for CKD progression associated with worsening of retinopathy in comparison with participants with stable retinopathy was 2.24 (95% CI, 1.28-3.91; P = .005) in univariable analysis among participants with baseline and follow-up photography. In the multivariable analysis, the OR was 1.62 (95% CI, 0.77-3.39; P = .20). The multiple imputation analysis provided similar results.

Conclusions and Relevance

Progression of retinopathy appears to be associated with progression of CKD on univariable analysis but not on multivariable analysis suggesting that similar risk factors may be affecting the progression of both retinal and chronic kidney disease.

Choroidal thickness is associated with renal hemodynamics in essential hypertension

The choroid is the most vascularized structure of the eye and plays a central role in the development of the retinal vascular changes that occur in arterial hypertension. Changes of choroidal thickness (ChT) assessed by optical coherence tomography (OCT) technology could reflect the vascular complications of hypertension. Also, intrarenal hemodynamic damage, associated with endothelial dysfunction, demonstrated to be a good indicator of systemic morphofunctional arterial impairment. The aim of this study is to assess the relationship between ChT and renal hemodynamics in subjects with essential hypertension. Routine laboratory tests, clinical history, and physical examination, including blood pressure assessment, were performed in 90 subjects with essential hypertension. All patients underwent Doppler ultrasonographic evaluation of intra-renal hemodynamics and OCT imaging to assess ChT. When subjects were divided in two groups based on renal resistive index (RRI), group I (RRI ≥ 75% percentile) showed significantly lower values of ChT than group II (RRI < 75% percentile) (P < .001). When divided in two groups based on the ChT median values, patients with lower ChT had significantly higher RRI values than those with ChT above the median values (P < .05). In multivariate model including age, eGFR, and other variables as confounding factors, RRI ≥ 75% was independently associated with ChT. ChT was significantly correlated with renal resistive index in subjects with essential hypertension, confirmed in multivariate analyses. This result could be referred to changes in vascular elastic properties that occur in retinal and intrarenal vascular system probably due to oxidative stress and endothelial dysfunction commonly found in early complications of hypertension.

Association between Free Thyroxine Levels and Diabetic Retinopathy in Euthyroid Patients with Type 2 Diabetes Mellitus

Background: This study aimed to evaluate the association between thyroid parameters and diabetic retinopathy (DR) in euthyroid patients with type 2 diabetes mellitus (T2DM).Materials and Methods: In this cross-sectional study, a total of 911 euthyroid patients with T2DM (539 men and 372 women; mean age, 60.81 ± 12.93 years) were enrolled. Clinical factors were assessed and free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels were measured. DR was diagnosed using fundus fluorescein angiography.Results: Compared with patients without DR (n = 718), patients with DR (n = 193) exhibited lower FT3 (4.40 ± 0.58 vs. 4.50 ± 0.51 pmol/L; P = .019) and FT4 (14.86 ± 2.09 vs. 15.91 ± 2.18 pmol/L; P < .001) and higher TSH (1.86 [1.22, 2.66] vs. 1.58 [1.14, 2.34] µIU/mL; P = .015) levels. After adjustment for potential DR risk factors, patients in the highest tertile of plasma FT4 levels had a 0.332-fold likelihood of developing DR compared with those in the lowest tertile of plasma FT4 levels (P_trend < 0.001). The prevalence of DR showed a significantly decreasing trend across the three tertiles based on FT4 levels (31.35%, 19.08% and 13.16%; P_trend < 0.001). Similar results were obtained for the presence of proliferative DR.Conclusion: These findings suggest that low-normal FT4 levels are associated with the prevalence of DR in euthyroid patients with T2DM.

Association of reduced inner retinal thicknesses with chronic kidney disease

BACKGROUND

Tissue derived biomarkers may offer utility as indicators of accumulated damage. Reduced thickness of retinal neuronal tissue and the vascular choroid have previously been associated with vascular damage and diabetes. We evaluated associations between retinal thickness, retinal microvascular and choroidal measures, and renal function in a population with a high burden of comorbidity.

METHODS

Participants were recruited from nuclear cardiology or renal medicine clinics. Retinal and choroidal thickness were measured from spectral-domain optical coherence tomograms. Retinal microvascular parameters were assessed from digital fundus photographs using a semi-automated software package.

MAIN OUTCOME MEASURE

Chronic kidney disease (CKD) categorised as: CKD stages 1-2, eGFR ≥60 ml/min/1.73m²; CKD stage 3, eGFR 30-59 ml/min/1.73m², and CKD stages 4-5, eGFR ≤29 ml/min/1.73m².

RESULTS

Participants (n = 241) had a mean age of 65 years and a mean eGFR of 66.9 ml/min/1.73m². Thirty-nine % of the cohort had diabetes and 27% were using diuretics. Thinning of the inner retina and changes to its microvascular blood supply were associated with lower eGFR and CKD stages 4 and 5, while no associations were found between the outer retinal layers or their choroidal blood supply and CKD of any stage. These associations remained following adjustment for age, mean arterial blood pressure, diabetes status, low-density lipoprotein, body mass index, and sex.

CONCLUSIONS

Inner retinal thinning and retinal microvascular variation is associated with advanced CKD (stages 4 & 5) independent of important confounding factors, but not with earlier stage CKD (stage 3) and, therefore, its utility as a biomarker for early CKD is not supported in this study.

Diabetes, Diabetic Complications, and Phosphate Toxicity: A Scoping Review

This article presents a scoping review and synthesis of research findings investigating the toxic cellular accumulation of dysregulated inorganic phosphate-phosphate toxicity-as a pathophysiological determinant of diabetes and diabetic complications. Phosphorus, an essential micronutrient, is closely linked to the cellular metabolism of glucose for energy production, and serum inorganic phosphate is often transported into cells along with glucose during insulin therapy. Mitochondrial dysfunction and apoptosis, endoplasmic reticulum stress, neuronal degeneration, and pancreatic cancer are associated with dysregulated levels of phosphate in diabetes. Ectopic calcification involving deposition of calcium-phosphate crystals is prevalent throughout diabetic complications, including vascular calcification, nephropathy, retinopathy, and bone disorders. A low-glycemic, low-phosphate dietary intervention is proposed for further investigations in the treatment and prevention of diabetes and related diabetic pathologies.

Effects of sodium-glucose cotransporter-2 inhibitors and dipeptidyl peptidase-4 inhibitors on diabetic retinopathy and its progression: A real-world Korean study

The sodium-glucose cotransporter-2 inhibitors (SGLT2is) reduce the incidence of macrovascular complications of diabetes, while their effect on diabetic retinopathy has not been clarified. We compared the effects of SGLT2is with those of dipeptidyl peptidase-4 inhibitors (DPP4is) on the risk of diabetic retinopathy and its progression in people with type 2 diabetes. We performed a retrospective cohort study among people with type 2 diabetes who started on a SGLT2i or DPP4i from 2014 to 2016 according to the Korean National Health Insurance Service database. Subjects initiated on a SGLT2i or DPP4i were matched on a 1:1 basis according to their propensity scores, and Cox proportional hazards regression models were used to calculate the hazard ratios for the risk of diabetic retinopathy and its progression. After propensity score-matching, 41,430 patients without a history of diabetic retinopathy were identified as new users of a SGLT2i (n = 20,175) or DPP4i (n = 20,175). The hazard ratio (95% CI) for diabetic retinopathy was 0.89 (0.83–0.97) for SGLT2i initiators compared with DPP4i initiators. In patients with a history of diabetic retinopathy (n = 4,663 pairs), there was no significant difference in diabetic retinopathy progression between SGLT2i initiators and DPP4i initiators (hazard ratio 0.94, 95% CI 0.78–1.13). This real-world cohort study showed that SGLT2is might be associated with lower risk of diabetic retinopathy compared with DPP4is. Randomized controlled trials are needed to investigate the long-term effect of SGLT2is in diabetic retinopathy in people with diabetes.

Patterns and Risk Factor Profiles of Visual Loss in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study

PURPOSE

To describe the pattern and risk factor traits associated with visual loss (defined as either visual impairment [VI] or blindness) in a multiethnic Asian cohort of Malay, Indian, and Chinese individuals living in Singapore.

METHODS

A total of 10 020 participants from the Singapore Epidemiology of Eye Diseases Study were examined between 2004 and 2011. All underwent standardized examinations. VI (visual acuity <20/40 to ≥20/200) and blindness (visual acuity <20/200) were defined based on the US definition, better-seeing eye. Singapore Population Census 2010 was used to calculate age-standardized prevalence. Multiple logistic regression analysis was performed to determine the independent and joint risk factors associated with visual loss.

RESULTS

Malay individuals had higher age-standardized prevalence of best-corrected and presenting VI (5.4% and 19.9%, respectively) than Indian (3.6% and 18.0%) and Chinese individuals (3.3% and 17.2%). Cataract was the main cause for presenting and best-corrected blindness; cataract and diabetic retinopathy were the top causes for best-corrected VI, consistently observed across the 3 ethnic groups. Older age, female sex, lower socioeconomic status, diabetes, systemic comorbidities, and cognitive impairment were independently associated with increased risk of best-corrected visual loss (all P ≤ .027). Individuals aged ≥60 years with diabetes were 12.7 times (95% confidence interval, 8.39-19.23) likely to have best-corrected visual loss, compared with younger, nondiabetic individuals. Lower income and education explained 58.1% and 23.2% of best-corrected visual loss in this population, respectively.

CONCLUSION

In this urban multiethnic Asian population, we identified common traits associated with visual loss across Malay, Indian, and Chinese individuals. These results will be useful for the planning and designing of eye health services and strategies for Asia's rapidly developing populations living in urban communities. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Retinal and choroidal vasculature changes associated with chronic kidney disease

PURPOSE

Retinal and choroidal microvascular changes can be related to renal impairment in hypertension and chronic kidney disease (CKD). The study examines the association between retinochoroidal parameters and renal impairment in hypertensive, non-diabetic patients.

METHODS

This is a cross-sectional study on Caucasian patients with systemic arterial hypertension with different levels of renal function. All subjects were studied by blood chemistry, urine examination, microalbuminuria and blood pressure. Complete eye examination was completed with swept source optical coherence tomography (SS-OCT) and optical coherence tomography angiography (OCTA) scans of macular region. Patients were divided in groups: LowGFR and HighGFR and CKD- and CKD+, according to the value of glomerular filtrate (GFR) and albuminuria. LowGFR and CKD+ groups included patients with clinical kidney impairment.

RESULTS

One hundred and twenty eyes of 120 hypertensive patients were evaluated. The mean retinal thickness was thinner in CKD+ versus CKD- group (p < 0.009). LowGFR and CKD+ groups showed thinner choroidal values than HighGFR (p < 0.02) and CKD- (p < 0.001) groups. OCTA showed lower density in LowGFR than in HighGFR group (p < 0.001) and in CKD+ versus CKD- group (p < 0.001). Albuminuria was inversely related to choroidal and retinal thickness measures (p < 0.001) and to the indices of superficial parafoveal (p < 0.05) and foveal (p < 0.05) vascular densities.

CONCLUSIONS

CKD is associated with retinal thinning, eGFR and decreasing renal function with progressive reduction of choroidal and retinal vascular density. SS-OCT and OCTA documented close association between CKD and reduction of both choroidal thickness and paracentral retinal vascular density in hypertensive patients.

Early retinal microvascular abnormalities in patients with chronic kidney disease

Objective

To evaluate early retinal microvascular abnormalities in patients with chronic kidney disease (CKD) via optical coherence tomography angiography.

Methods

A cross‐sectional study. Two hundred patients with CKD stage ≧3 were enrolled in the CKD group, and 50 age‐matched healthy subjects were enrolled in the control group. Main outcome measures were the differences in parafoveal vessel densities in the superficial vascular plexus (SVP) and deep vascular plexus (DVP) between the CKD and control groups.

Results

The mean ages were 62.7 ± 10.1 in the CKD group and 61.9 ± 9.7 (P = 0.622) in the control group. The CKD group had reduced parafoveal vessel densities in SVP (46.7 ± 4.3 vs 49.7 ± 2.9, P < 0.001) and DVP (50.1 ± 4.1 vs 52. 6 ± 2.9, P < 0.001) when compared to those of the control group. In multiple linear regression models, age, diabetes, estimated glomerular filtration rate, and use of anti‐hypertensive drugs were factors associated with vessel density in SVP, whereas age, diabetes, and smoking were factors associated with vessel density in DVP.

Conclusion

Patients with CKD had reduced vessel densities in parafoveal SVP and DVP, as compared to that of control subjects. Microvasculature in the different retinal layers may be affected by different systemic factors.

Serous retinal detachment in preeclampsia and malignant hypertension

OBJECTIVES

To compare and evaluate the characteristics of hypertensive choroidopathy with serous retinal detachment in preeclampsia and malignant hypertension (HTN) and explore choroidal ischemia as a pathogenesis using multimodal imaging.

METHODS

A retrospective multicenter case series. Medical charts were reviewed. Clinical characteristics and multimodal imaging, including optical coherence tomography (OCT) and OCT angiography (OCTA), were evaluated.

RESULTS

Fifty-three eyes of 29 preeclampsia patients and 45 eyes of 24 HTN patients were included. There were no differences in age, follow-up duration, baseline visual acuity, central macular thickness (CMT), or subfoveal choroidal thickness (CT) between the two groups. Blood pressure parameters, including systolic blood pressure, diastolic blood pressure, and pulse rate, were significantly higher in the HTN group. After serous retinal detachment resolved, both CMT (p < 0.001) and CT (p = 0.003) decreased more in the preeclampsia group. Hypertensive retinopathy features, including hemorrhage, exudates, cotton-wool spots, and optic disc edema, were predominantly found in the HTN group (p = 0.001). Final visual acuity was better in the preeclampsia group than in the HTN group (p = 0.048). Poor visual prognostic factors included the presence of retinopathy features (p = 0.005) and retinal detachment in the macula (p = 0.017).

CONCLUSION

Choroidal circulation may be affected earlier than retinal circulation by elevated blood pressure, presumably because of anatomical differences and autoregulatory mechanisms in the retinal vasculature. Serous retinal detachment with hypertensive choroidopathy presented with choroidal thickening that decreased after resolution, but the residual flow defects observed in the choriocapillaris on OCTA confirmed the long-hypothesized notion that ischemia is a mechanism underlying hypertensive choroidopathy.

Vision Impairment in CKD Patients: Epidemiology, Mechanisms, Differential Diagnoses, and Prevention

Eyes and kidneys have numerous structural, developmental, physiologic, and pathogenic pathways in common, suggesting that many kidney and eye diseases may be interlinked. Studies suggest that the prevalence of eye diseases and vision impairment are higher among persons with end-stage kidney disease and earlier stages of chronic kidney disease (CKD) than in those without. Ocular morbidity in persons with CKD and end-stage kidney disease may be due to the following risk factors: (1) underlying conditions and risk factors for CKD such as diabetes or hypertension, (2) metabolic disorders associated with CKD, (3) uremia and anemia, and (4) CKD treatment. Among the chief eye diseases, diabetic retinopathy and age-related macular degeneration are most consistently associated with CKD. Further research for eye diseases such as glaucoma and cataract is needed to determine their relationships with CKD. Despite the high prevalence and burden of vision impairment among persons with CKD, eye screening in patients with CKD is not currently recommended as standard practice. This review suggests that patients with CKD should be encouraged to undergo a complete eye examination. Furthermore, physicians should be aware that patients undergoing dialysis may develop acute eye problems such as acute glaucoma, and appropriate referral to ophthalmologists should be considered in those with a history of glaucoma or recent ocular surgery. Interdisciplinary collaboration between nephrologists and ophthalmologists will ensure enhanced and appropriate management of patients with CKD.

Associations of renal function with diabetic retinopathy and visual impairment in type 2 diabetes: A multicenter nationwide cross-sectional study

BACKGROUND

Diabetic retinopathy (DR) separately has been noted as a major public health problem worldwide as well. Currently, many studies have demonstrated an association between diabetic nephropathy and DR in type 1 diabetes mellitus (T1DM) patients, but this association is less strong in T2DM. The evidence for an association between renal function and DR and visual impairment among T2DM patients is limited, particularly in the Asian population.

AIM

To assess the association between glomerular filtration rate (GFR) and DR, severe DR, and severe visual impairment among T2DM patients in Thailand.

METHODS

We conducted a nationwide cross-sectional study based on the DM/HT study of the Medical Research Network of the Consortium of Thai Medical Schools. This study evaluated adult T2DM patients from 831 public hospitals in Thailand in the year 2013. GFR was categorized into ≥ 90, 60-89, 30-59 and < 30 mL/min/1.73 m². The association between GFR and DR, severe DR, and severe visual impairment were assessed using multivariate logistic regression.

RESULTS

A total of 13192 T2DM patients with available GFR were included in the analysis. The mean GFR was 66.9 ± 25.8 mL/min/1.73 m². The prevalence of DR, proliferative DR, diabetic macular edema, and severe visual impairment were 12.4%, 1.8%, 0.2%, and 2.1%, respectively. Patients with GFR of 60-89, 30-59 and < 30 mL/min/1.73 m² were significantly associated with increased DR and severe DR when compared with patients with GFR of ≥ 90 mL/min/1.73 m². In addition, increased severe visual impairment was associated with GFR 30-59 and < 30 mL/min/1.73 m².

CONCLUSION

Decreased GFR was independently associated with increased DR, severe DR, and severe visual impairment. GFR should be monitored in diabetic patients for DR awareness and prevention.

Prevalence of Diabetic Retinopathy and Associated Mortality Among Diabetic Adults With and Without Chronic Kidney Disease

PURPOSE

To estimate prevalence and severity of diabetic retinopathy (DR) among U.S. adults with diabetes and with or without chronic kidney disease (CKD), and assess associated risk of mortality.

DESIGN

Cross-sectional study with national survey data.

METHODS

The cohort included adults ≥40 years old with diabetes in the National Health and Nutrition Examination Surveys (NHANES) 2005-2008. Vital status was determined through December 31, 2011. We defined diabetes as hemoglobin A1c ≥6.5% or self-report and CKD by urinary albumin/creatinine ≥30 mg/g or glomerular filtration rate <60 mL/min/1.73 m². The main outcomes were DR and mortality.

RESULTS

Prevalence of DR was 27.8% (95% CI 24.3-31.7), 36.2% (95%CI 30.1-42.7), and 23.4% (95% CI 19.2-28.1), overall, with and without CKD. Prevalence of vision-threatening DR was 4.2% (95% CI 3.2-5.5), 8.2% (95% CI 5.4-12.2), and 2.0% (95% CI 1.2-3.5), respectively. In a multivariable adjusted model, DR was positively but nonsignificantly associated with CKD (OR = 1.1, 95% CI 0.7-1.7), was 40% higher per 1% increase in hemoglobin A1c (OR = 1.4, 95% CI 1.1-1.6), was 30% higher per 5 years additional diabetes duration (OR = 1.3, 95% CI 1.1-1.5), was 30% higher per 10 mm Hg increase in systolic blood pressure (OR = 1.3, 95% CI 1.1-1.5), and was 6-fold higher with insulin treatment (OR = 6.2, 95% CI 2.6-14.8). Compared with diabetic participants with neither DR nor CKD, those with DR and CKD had a 3.6-fold (95% CI 1.5-9.1) increased adjusted risk for all-cause mortality.

CONCLUSIONS

Over one third of persons with diabetes and CKD had DR. The risk of death was higher with than without CKD and DR. Many of the studied risk factors associated with DR are modifiable.

Evidence of altered brain network centrality in patients with diabetic nephropathy and retinopathy: an fMRI study using a voxel-wise degree centrality approach

BACKGROUND

Over recent years, some researchers believe that diabetic nephropathy (DN) and diabetic retinopathy (DR) both independently increase the incidence of brain diseases, such as stroke, cerebral infarction, and cerebral hemorrhage. In the present study, we used the voxel-wise degree centrality (DC) method to investigate potential changes of functional network brain activity in patients with DN and retinopathy (DNR).

METHODS

Twenty DNR patients (9 men, 11 women) and 20 healthy controls (HCs; 9 men, 11 women) were recruited; the controls were matched for age, sex, and educational background. All subjects underwent resting-state functional magnetic resonance imaging. Ophthalmoscopy, renal biopsy and single-photon emission computed tomography were used to evaluate microvascular lesions in the eye and kidney. Data were categorized using receiver operating characteristic curves, and correlation analysis was performed using Pearson's correlation analysis.

RESULTS

Compared with HCs, DNR patients showed reduced mean DC values in the right inferior temporal gyrus (RITG) and left subcallosal gyrus regions (LSG) and increased mean DC values in the bilateral precuneus (BP). Moreover, mean DC in the BP was correlated with renal estimated glomerular filtration rate (eGFR; r = 0.762). The area under the curve (AUC) value was 0.829 for BP and 0.839 for RITG and LSG.

CONCLUSION

DNR patients showed dysfunction in three different brain regions. The linear correlation between eGFR and mean brain DC values indicates the presence of common diabetic microangiopathy in the brain and kidney, which may provide new ideas for multiorgan microvascular lesions of diabetics.

Potent Oral Hypoglycemic Agents for Microvascular Complication: Sodium-Glucose Cotransporter 2 Inhibitors for Diabetic Retinopathy

The purpose of this study was to investigate the effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on the progression of diabetic retinopathy (DR) in patients with type 2 diabetes. The medical records of 21 type 2 diabetic patients who used a SGLT2i and 71 patients with sulfonylurea (control) were reviewed retrospectively. The severity of DR was assessed using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. Fewer patients who used a SGLT2i than control patients with sulfonylurea showed progression of DR based on ETDRS scale (44% versus 14%, P = 0.014). Moreover, treatment with a SGLT2i was associated with a significantly lower risk of DR progression (P = 0.021), and this effect remained significant after adjusting for the age, duration of diabetes, initial DR grade, and HbA1c level by propensity score matching (P = 0.013). Treatment of type 2 diabetic patients with a SGLT2i slowed the progression of DR compared to sulfonylurea, which is independent of its effect on glycemic control. This study provides a foundation for further evaluation of the effect of SGLT2i on the progression of DR.

Serum Phosphate and Retinal Microvascular Changes: The Multi-Ethnic Study of Atherosclerosis and the Beaver Dam Eye Study

PURPOSE

Higher levels of serum phosphate are strongly linked to increased risk of cardiovascular disease and therapies aimed to lower serum phosphate are employed in the management of patients with chronic kidney disease (CKD). Data are limited, however, on serum phosphate as a risk factor for microvascular disease in community-based populations. It is important to determine the impact of novel risk factors, such as phosphate, on the microvasculature.

METHODS

We conducted a prospective study of 3919 individuals in the Multi-Ethnic Study of Atherosclerosis (MESA) and 3544 individuals in the Beaver Dam Eye Study (BDES) to test the associations of serum phosphate with retinopathy and retinal vessel caliber, and change in retinopathy severity and change in retinal vessel caliber.

RESULTS

Mean (standard deviation) serum phosphate was 3.66 (0.52) mg/dl in the MESA and 3.77 (0.55) mg/dl in the BDES. In multivariable adjusted models, phosphate was significantly associated with prevalent retinopathy in the MESA (Odds Ratio [OR] per 1 mg/dl increase in phosphate, 1.22; Confidence Interval [CI] 1.02-1.47) and the BDES (OR 1.06; CI 1.01-1.11). In stratified analyses, these relationships were even stronger and only seen in individuals with diabetes in both the MESA (OR 1.81; CI 1.30-2.53) and the BDES (OR 1.16; CI 1.05-1.29). Phosphate was not associated with incident or change in retinopathy severity, nor any retinal caliber outcome.

CONCLUSIONS

Among community-living individuals with low prevalence of CKD, higher serum phosphate was associated with prevalent retinopathy in individuals with diabetes. Further longitudinal assessments in patients with diabetes necessitate further investigation.

Increased stroke risk among patients with open-angle glaucoma: a 10-year follow-up cohort study

BACKGROUND

Although several studies showed the association between stroke and open-angle glaucoma (OAG), there is still lack of longitudinal studies based on large populations. Therefore, in this study, we investigated the risk of stroke after OAG diagnosis over a 10-year follow-up period.

METHODS

We performed a retrospective nationwide propensity score-matched cohort study. OAG and comparison groups were selected from a large database from the Korean National Health Insurance Service, comprising 1 025 340 random subjects. The OAG group comprised patients with an initial diagnosis of OAG between January 2004 and December 2007 (n=1520), and the comparison group comprised randomly selected patients (five per glaucoma patient; n=7570). Each cohort was tracked until 2013 for stroke development. Cox proportional hazard regression analysis was performed to determine possible association RESULTS: OAG was associated with increased stroke incidence (HR=1.20, 95% CI 1.03 to 1.40). Hypertension, diabetes mellitus, chronic renal failure, atrial fibrillation, hyperlipidaemia, increasing age and male gender also increased the incidences of stroke. Risk of stroke for patients with OAG was greater in the older age group (≥65 years, HR=1.23, 95% CI 1.02 to 1.47) than in the younger age group (<65 years, HR=1.12, 95% CI 0.86 to 1.46), and greater in males (HR=1.31, 95% CI 1.06 to 1.60) than in females (HR=1.10, 95% CI 0.88 to 1.38).

CONCLUSIONS

Patients who were diagnosed with OAG were more likely to experience subsequent stroke than comparison group without OAG, and the risk was greater for older adults and males.

Diabetic retinopathy is associated with diastolic dysfunction in type 2 diabetic patients with non-ischemic dilated cardiomyopathy

BACKGROUND

To investigate the association between diabetic retinopathy (DR) and myocardial dysfunction in patients with type 2 diabetes and dilated cardiomyopathy (dCMP).

METHODS

Data were collected retrospectively from 89 patients with dCMP (46 with type 2 diabetes and 43 without diabetes) and no evidence of coronary artery disease. Echocardiographic parameters and laboratory data, including lipid profiles and fundus findings, were obtained from medical records. A left ventricular ejection fraction (LVEF) less than 40% was considered impaired systolic function, while an E/E' ratio greater than 15 was considered elevated left ventricular (LV) filling pressure.

RESULTS

Baseline characteristics show that LVEF was not significantly different between patients with and without diabetes or between diabetic patients with and without DR. Among the diastolic function parameters, patients with DR exhibited higher E/E' ratios (left ventricular filling pressures) than patients without DR (23.75 ± 13.37 vs 11.71 ± 3.50, P = 0.022). Logistic regression analysis revealed that statin use lowered the risk of impaired systolic dysfunction in all patients (odds ratio (OR) 0.33, 95% confidence interval (CI) 0.12-0.92, P = 0.034) and in patients with diabetes (OR 0.273, 95% CI 0.08-0.99, P = 0.049), while the presence of DR was associated with a higher risk of elevated LV filling filling pressure in patients with diabetes (OR 18.00, 95% CI 1.50-216.62, P = 0.023).

CONCLUSIONS

In conclusion, DR was associated with elevated LV filling pressure in patients with dCMP. DR may not only represent microvascular long-term complications in patients with diabetes but may also be associated with more advanced form of diastolic dysfunction among diabetic patients with cardiomyopathy.

Achievement of metabolic control among children and adolescents with type 1 diabetes in Spain

AIMS

To assess metabolic control in a paediatric T1D population in Spain and analyse the rate of severe acute decompensations and chronic complications.

METHODS

Data from patients treated at eight paediatric diabetes units with experienced diabetes teams between June and December 2014 were analysed in an observational prospective study. Variables included: age, sex, diabetes duration, number of follow-up visits/year, anthropometrical data, insulin treatment modalities, mean annual HbA1c and the prevalence of acute and chronic complications. SPSS statistics 21.0 was used.

RESULTS

A total of 853 patients (49.7% female) with a mean age of 12.1 ± 3.7 years were included. Anthropometric data were normal. Mean diabetes duration was 8 ± 3.4 years. Mean outpatient follow-up was 4.7 ± 0.04 visits/year. Twenty-five per cent were on continuous subcutaneous insulin infusion (CSII). Mean HbA1c was 7.3 ± 1% (56 ± 8 mmol/mol) and 66.6% had HbA1c < 7.5% (58 mmol/mol). HbA1c value correlated negatively with age at onset and positively with years of diabetes, number of visits/year and current age (F = 7.06; p = 0.01). Patients on CSII (n = 213) were younger, attended the outpatient clinic more frequently, were diagnosed earlier, had better metabolic control and had presented more severe hypoglycaemic episodes the previous year. The rate of severe decompensation (episodes/100 patients/year) was ketoacidosis 1.5 and severe hypoglycaemia 4.5. The prevalence of chronic complications was very low.

CONCLUSIONS

Our data describe the good compliance of paediatric T1D patients treated at eight paediatric units in Spain following international standards of metabolic control.

Update on Diagnosis and Treatment of Diabetic Retinopathy: A Consensus Guideline of the Working Group of Ocular Health (Spanish Society of Diabetes and Spanish Vitreous and Retina Society)

A group of members of the Spanish Retina and Vitreous Society (SERV) and of the Working Group of Ocular Health of the Spanish Society of Diabetes (SED) updated knowledge regarding the diagnosis and treatment of diabetic retinopathy (DR) based on recent evidence reported in the literature. A synthesis of this consensus forms the basis of the present review, which is intended to inform clinicians on current advances in the field of DR and their clinical applicability to patients with this disease. Aspects presented in this article include screening procedures of DR, new technologies in the early diagnosis of DR, control of risk factors in the different stages of the disease, indications of panretinal laser photocoagulation, efficacy of intravitreal antiangiogenic agents and steroids, and surgical options for treating DR-related complications. Practical information regarding periodicity of screening procedures in patients with type 1 and type 2 diabetes, ophthalmological controls according to the stage of retinopathy and complications, and criteria and degree of urgency for referral of a DR patient to the ophthalmologist are also presented.

Association between Chronic Kidney Disease and Risk of Cataract: A Nationwide Retrospective Cohort Study

BACKGROUND

Previous studies have established a relationship between chronic kidney disease (CKD) and cataract, but the relationship between the severity of renal impairment and risk of cataract is uncertain. This study investigates the relationship between the severity of renal disease and cataract in a nationwide sample from Taiwan.

METHODS

The cohort from 1-million National Health Insurance beneficiaries from Taiwan was retrospectively analyzed. All adult beneficiaries were followed from January 1, 2005 until December 31, 2013, to identify patients who underwent cataract surgeries. On the basis of the ambulatory care records, those diagnosed with CKD (ICD-9-CM code: 585) during the follow-up period were enrolled as CKD patients after careful evaluation. Each patient with CKD was age- and gender-matched with 4 individuals who did not have CKD. Cox regression models were applied to compare the hazard of cataract surgery in individuals with and without CKD. Subgroup analysis was used to compare patients with end-stage renal disease (ESRD) with age- and gender-matched non-CKD individuals. ESRD was defined by CKD patients who need regular renal replacement therapy. The same method was applied to evaluate hazard ratios (HRs).

RESULTS

After age and gender matching, there were 11,881 patients in the CKD group and 47,524 in the non-CKD group. After control for possible confounding, the adjusted HR (aHR) of cataract was 1.84 (95% CI 1.73-1.95) for the CKD group. Subgroup analysis of patients with ESRD (n = 3,209) and non-CKD individuals (n = 12,836), with matching done on the basis of age and gender, indicated an aHR of cataract was 2.33 (95% CI 2.10-2.59) for the ESRD group.

CONCLUSIONS

This study indicates a relationship between CKD and cataract, and suggests that the risk for cataract increases with the severity of renal impairment.

RISK OF AGE-RELATED MACULAR DEGENERATION IN END-STAGE RENAL DISEASE PATIENTS RECEIVING LONG-TERM DIALYSIS

PURPOSE

This study investigated the risk of age-related macular degeneration (AMD) in patients with end-stage renal disease (ESRD) receiving long-term dialysis and compared the risk between various dialysis modalities using propensity score-matching methods.

METHODS

From the National Health Insurance Research Database of Taiwan, the authors identified 27,232 patients with ESRD newly diagnosed from 2000 to 2010, including 9,287 patients on peritoneal dialysis (PD) and 17,945 patients on hemodialysis (HD). A total of 108,928 controls without kidney disease were randomly selected and frequency matched by age, sex, and index year of ESRD patients. The authors established an additional HD cohort matched by propensity scores of PD patients (N = 9,256 each). All cohorts were followed up until the end of 2011 to measure the incidence of AMD.

RESULTS

The incidences of AMD were 1.84, 4.03, 5.37, and 3.50 per 1,000 person-years in the control, ESRD (PD and HD), PD, and HD cohorts, respectively. The hazard ratios for AMD were 1.72, 2.47, and 1.43 for the ESRD, PD, and HD cohorts, with 95% confidence intervals of 1.50 to 1.97, 2.05 to 2.98, and 1.22 to 1.68, respectively, compared with the control cohort. The patients on PD exhibited a hazard ratio of 1.74 (95% confidence interval = 1.27-2.38) for developing AMD compared with propensity score-matched patients on HD.

CONCLUSION

Patients with ESRD may exhibit a higher risk of AMD than people without kidney disease. Patients on PD may be more likely to develop AMD than patients on HD.

Effects of Lycium barbarum on the Visual System

Lycium barbarum (wolfberry, gogi berry, gouqizi, ) is one of the most widely used Chinese herbal medicines (CHMs) and is also one of the most scientifically studied. Indeed, the polysaccharide component of this berry (LBP) has been shown to have antioxidant, antiinflammatory, antiexcitotoxic, and antiapoptotic properties. These properties make it a particularly useful treatment option for the ocular environment. Although there are a handful of studies investigating the use of LBP to treat diseases affecting the lens, the vast majority of the published literature investigating LBP in the visual system focus on the retina. In this chapter, we have described what is currently understood concerning the effects of LBP treatment on various retinal diseases, including glaucoma, ischemia/reperfusion, age-related macular degeneration, retinitis pigmentosa, and diabetic retinopathy. We then describe the functions attributed to LBP using other cellular contexts to elucidate the full mechanisms this CHM utilizes in the retina. By making connections between what is known about the function of LBP in a variety of tissues and its function as a therapy for retinal degenerative diseases, we hope to further emphasize the continued use of this CHM in clinical medicine in addition to providing a platform for additional study.

Cigarette smoking and cardio-renal events in patients with atherosclerotic renal artery stenosis

Cigarette smoking causes cardiovascular disease and is associated with poor kidney function in individuals with diabetes mellitus and primary kidney diseases. However, the association of smoking on patients with atherosclerotic renal artery stenosis has not been studied. The current study utilized data from the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL, NCT00081731) clinical trial to evaluate the effects of smoking on the risk of cardio-renal events and kidney function in this population. Baseline data showed that smokers (n = 277 out of 931) were significantly younger at enrollment than non-smokers (63.3±9.1 years vs 72.4±7.8 years; p<0.001). In addition, patients who smoke were also more likely to have bilateral renal artery stenoses and peripheral vascular disease (PVD). Longitudinal analysis showed that smokers experienced composite endpoint events (defined as first occurrence of: stroke; cardiovascular or renal death; myocardial infarction; hospitalization for congestive heart failure; permanent renal replacement; and progressive renal insufficiency defined as 30% reduction of GFR from baseline sustained for ≥ 60 days) at a substantially younger age compared to non-smokers (67.1±9.0 versus 76.1±7.9, p<0.001). Using linear regression and generalized linear modeling analysis controlled by age, sex, and ethnicity, smokers had significantly higher cystatin C levels (1.3±0.7 vs 1.2±0.9, p<0.01) whereas creatinine and estimated glomerular filtration rate (eGFR) were not different from non-smokers. From these data we conclude that smoking has a significant association with deleterious cardio-renal outcomes in patients with renovascular hypertension.

The Malaysian Cataract Surgery Registry: risk Indicators for posterior capsular rupture

AIM

To identify the risk indicators for posterior capsular rupture (PCR) in the Malaysian Cataract Surgery Registry (CSR).

METHODS

Data from the web-based CSR were collected for cataract surgery performed from 2008 to 2013. Data was contributed by 36 Malaysian Ministry of Health public hospitals. Information on patient's age, ethnicity, cause of cataract, ocular and systemic comorbidity, type of cataract surgery performed, local anaesthesia and surgeon's status was noted. Combined procedures and type of hospital admission were recorded. PCR risk indicators were identified using logistic regression analysis to produce adjusted OR for the variables of interest.

RESULTS

A total of 150 213 cataract operations were registered with an overall PCR rate of 3.2%. Risk indicators for PCR from multiple logistic regression were advancing age, male gender (95% CI 1.04 to 1.17; OR 1.11), pseudoexfoliation (95% CI 1.02 to 1.82; OR 1.36), phacomorphic lens (95% CI 1.25 to 3.06; OR 1.96), diabetes mellitus (95% CI 1.13 to 1.29; OR 1.20) and renal failure (95% CI 1.09 to 1.55; OR 1.30). Surgical PCR risk factors were combined vitreoretinal surgery (95% CI 2.29 to 3.63; OR 2.88) and less experienced cataract surgeons. Extracapsular cataract extraction (95% CI 0.76 to 0.91; OR 0.83) and kinetic anaesthesia were associated with lower PCR rates.

CONCLUSIONS

This study was agreed with other studies for the risk factors of PCR with the exception of local anaesthesia given and type of cataract surgery. Better identification of high-risk patients for PCR decreases intraoperative complications and improves cataract surgical outcomes.

Association between macular degeneration and mild to moderate chronic kidney disease: A nationwide population-based study

Chronic kidney disease (CKD) and macular degeneration (MD) are 2 grave diseases leading to significant disability secondary to renal failure and blindness. The 2 diseases share not only common risk factors but also similar pathogenic mechanisms to renal and retinal injuries. Previous epidemiological studies indicated association between these 2 diseases. However, this concept is challenged by recent investigations. Patients with mild to moderate CKD (n = 30,696) between January 1, 1995 and December 31, 2005 were selected from the Taiwan National Health Insurance Database. Controls (n = 122,784) were matched by age, gender, diabetes mellitus type 2, and hypertension status (1:4 ratios). The risk of MD was compared between the 2 groups. The mean age of patients was 54.9 ± 15.7 years. The proportion of MD was 2.7% in mild to moderate CKD patients and 1.9% in normal controls (P < 0.001); and, 0.39% and 0.26% (P < 0.001) in advanced MD. Mild to moderate CKD patients had higher risk for MD [adjusted odds ratio (OR), 1.301; 95% confidence interval (CI), 1.200-1.411; P < 0.001] than normal renal function subjects. The association was more pronounced for advanced MD. From all age strata (10 years increase), the presence of CKD in those patients aged less than 40 years had highest OR for all MD (OR = 2.125, 95% CI: 1.417-3.186, P < 0.001). The results were consistent in interaction terms, highlighting the importance of CKD in young age patient for risk of MD. The high risk for MD in mild to moderate CKD patients remains significant after adjustment for personal habits (alcohol drinking and smoking, model 1; OR: 1.371; 95% CI: 1.265-1.486; P < 0.001), comorbidities (dyslipidemia, cerebrovascular disease, and peripheral vascular disease, model 2; OR: 1.369; 95% CI: 1.264-1.484; P < 0.001) and all these factors (model 3; OR: 1.320, 95% CI: 1.218-1.431, P < 0.001). This association was consistent in the subanalysis, excluding those patients with diabetic retinopathy. Proper diagnosis and timely intervention should be warranted to retard visual loss of these patients.

Association between Decreased Renal Function and Reticular Macular Disease in Age-Related Macular Degeneration

PURPOSE

To compare renal function in patients with age-related macular degeneration (AMD) with and without concurrent reticular macular disease (RMD).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients with documented AMD with and without RMD.

METHODS

Via our electronic health record system, we retrospectively identified patients assigned an International Classification of Diseases, Ninth Edition, code associated with AMD between January 2012 and January 2016. Patients met inclusion criteria if they had at least 1 macular spectral-domain optical coherence tomography volume scan, 1 provider note, and 1 glomerular filtration rate (GFR) value in the electronic medical record. We evaluated images for the presence or absence of RMD; we defined RMD as the presence of at least 1 subretinal drusenoid deposit in at least 1 macular slice. Patients with RMD in at least 1 eye were deemed RMD positive. Patients with bilateral choroidal neovascularization were excluded from analysis.

MAIN OUTCOME MEASURE

Observation of renal function in RMD patients.

RESULTS

Inclusion criteria were met by 119 patients (mean age, 75 years; range, 46-101 years). To account for the significant difference in RMD prevalence at extreme ages, we limited our study population to 107 patients 50 to 90 years of age. A GFR less than 60 ml/min/1.73 m² was found in 45.0% (27/60) of those with RMD compared with 12.8% (6/47) of those without RMD (odds ratio, 5.6; 95% confidence interval, 2.1-15). Multivariate logistic regression indicated that low GFR was a significant predictor for RMD, even after accounting for differences in age, diabetes, hypertension, hyperlipidemia, and other potential confounders. When comparing within classification subsets for RMD and GFR in patients with choroidal thickness data, significant choroidal thinning was associated with RMD (170 vs. 228 μm; P = 0.01) and GFR less than 60 ml/min/1.73 m² (144 vs. 219 μm; P = 0.0008).

CONCLUSIONS

Our analysis showed an association between RMD and renal dysfunction. Larger cross-sectional and longitudinal studies of the association of RMD with kidney function are warranted to better understand the nature and biological basis of this observed connection.

Chorioretinal thinning in chronic kidney disease links to inflammation and endothelial dysfunction

BACKGROUND. Chronic kidney disease (CKD) is strongly associated with cardiovascular disease and there is an established association between vasculopathy affecting the kidney and eye. Optical coherence tomography (OCT) is a novel, rapid method for high-definition imaging of the retina and choroid. Its use in patients at high cardiovascular disease risk remains unexplored.

METHODS. We used the new SPECTRALIS OCT machine to examine retinal and retinal nerve fiber layer (RNFL) thickness, macular volume, and choroidal thickness in a prospective cross-sectional study in 150 subjects: 50 patients with hypertension (defined as a documented clinic BP greater than or equal to 140/90 mmHg (prior to starting any treatment) with no underlying cause identified); 50 with CKD (estimated glomerular filtration rate (eGFR) 8–125 ml/min/1.73 m²); and 50 matched healthy controls. We excluded those with diabetes. The same, masked ophthalmologist carried out each study. Plasma IL-6, TNF-α , asymmetric dimethylarginine (ADMA), and endothelin-1 (ET-1), as measures of inflammation and endothelial function, were also assessed.

RESULTS. Retinal thickness, macular volume, and choroidal thickness were all reduced in CKD compared with hypertensive and healthy subjects (for retinal thickness and macular volume P < 0.0001 for CKD vs. healthy and for CKD vs. hypertensive subjects; for choroidal thickness P < 0.001 for CKD vs. healthy and for CKD vs. hypertensive subjects). RNFL thickness did not differ between groups. Interestingly, a thinner choroid was associated with a lower eGFR (r = 0.35, P <0.0001) and, in CKD, with proteinuria (r = –0.58, P < 0.001) as well as increased circulating C-reactive protein (r = –0.57, P = 0.0002), IL-6 (r = –0.40, P < 0.01), ADMA (r = –0.37, P = 0.02), and ET-1 (r = –0.44, P < 0.01). Finally, choroidal thinning was associated with renal histological inflammation and arterial stiffness. In a model of hypertension, choroidal thinning was seen only in the presence of renal injury.

CONCLUSIONS. Chorioretinal thinning in CKD is associated with lower eGFR and greater proteinuria, but not BP. Larger studies, in more targeted groups of patients, are now needed to clarify whether these eye changes reflect the natural history of CKD. Similarly, the associations with arterial stiffness, inflammation, and endothelial dysfunction warrant further examination.

TRIAL REGISTRATION. Registration number at www.clinicalTrials.gov: NCT02132741.

SOURCE OF FUNDING. TR was supported by a bursary from the Erasmus Medical Centre, Rotterdam. JJMHvB was supported by a bursary from the Utrecht University. JRC is supported by a Rowling Scholarship. SB was supported by a Wellcome Trust funded clinical research fellowship from the Scottish Translational Medicine and Therapeutics Initiative, and by a Rowling Scholarship, at the time of this work. ND is supported by a British Heart Foundation Intermediate Clinical Research Fellowship (FS/13/30/29994).

Chorioretinal thinning relates to the degree of inflammation and kidney injury in patients with kidney disease.

The association of geographic atrophy and decreased renal function in patients with age-related macular degeneration

PurposeThe purpose of the study was to investigate the association between area and presence of geographic atrophy (GA) and renal function, as measured by glomerular filtration rate (GFR).Patients and methodsWe retrospectively identified patients aged 50-90 years who were assigned an ICD-9 diagnosis code for age-related macular generation (AMD) between January 2012 and January 2016. Patients met inclusion criteria if they had at least one macular spectral domain optical coherence tomography volume scan, one provider note, and one GFR value in the electronic medical record. Images were evaluated for the presence of GA, area of GA, drusen, and subretinal drusenoid deposits (SDD) and for subfoveal choroidal thickness (CTh) by standard criteria. Imaging findings were correlated with the most recent GFR from the patient's chart.ResultsWe identified 107 patients who met our inclusion criteria (mean age=74 years, range 50-90 years). Overall, we found a significant correlation between the presence of GA and reduced GFR (P=0.002), which was maintained even after accounting for age and other confounders. No association between GFR and GA area was found. CTh was significantly lower in patients with GA (P=0.038) and those with decreased GFR (P=0.004). Within the SDD-positive population, GA was associated with reduced GFR (P=0.007) but only trended toward significance after controlling for age.ConclusionOur study findings demonstrate an association between impaired renal function and the presence, but not area, of GA within an AMD population. These findings may shed light on common pathogenic mechanisms for these two diseases.

Associations between recent severe hypoglycemia, retinal vessel diameters, and cognition in adults with type 1 diabetes

AIMS

Mild cognitive dysfunction has been identified in children and adults with type 1 diabetes, but most studies have failed to find a relationship between severe hypoglycemia and cognition, despite reports of such associations in older adults with type 2 diabetes. Focusing on older adults with type 1 diabetes, we examined the associations between cognitive performance and recent episodes of severe hypoglycemia, retinal vessel diameters and the presence of micro- and macrovascular complications.

METHODS

Cognitive functioning was assessed in 244 participants enrolled in the Wisconsin Epidemiologic Study of Diabetic Retinopathy. The mean (SD; range) age at assessment in 2012-14 was 55.2 (8.3; 37-82) years and the mean (SD) duration of diabetes was 41.1 (5.6) years. Three cognitive domains were assessed in this cross-sectional study: mental efficiency and executive function, nonverbal memory, and verbal memory.

RESULTS

Multivariate modeling demonstrated that although age and/or education are most strongly associated with performance on measures of mental efficiency, three diabetes-related variables were also associated with poorer test scores: an episode of severe hypoglycemia in the past year (β=-0.360 [95% CI, -0.672, -0.047]), retinal arteriolar and venular diameters (β=0.140 [95% CI, 0.062, 0.219]; β=-0.127 [95% CI -0.207, -0.047]), and carotid artery plaque (β=-0.372 [95% CI -0.741, -0.003]). In addition, recent severe hypoglycemia was associated with poorer nonverbal memory (β=-0.522 [95% CI, -0.849, -0.194]).

CONCLUSIONS

For middle-aged and older adults with long-duration type 1 diabetes, poorer cognition was associated with a recent episode of severe hypoglycemia as well as with the presence of micro- and/or macrovascular conditions. Given the increasing numbers of aging adults with type 1 diabetes, future longitudinal studies are needed to identify causality and to determine whether diabetes management techniques that reduce the onset or severity of vascular complications and hypoglycemia can also reduce the risk of cognitive dysfunction in this population.