Choroidal thickness alterations in diabetic nephropathy patients with early or no diabetic retinopathy

Artificial Intelligence-Assisted Perfusion Density as Biomarker for Screening Diabetic Nephropathy

Purpose

To identify a reliable biomarker for screening diabetic nephropathy (DN) using artificial intelligence (AI)-assisted ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA).

Methods

This study analyzed data from 169 patients (287 eyes) with type 2 diabetes mellitus (T2DM), resulting in 15,211 individual data points. These data points included basic demographic information, clinical data, and retinal and choroidal data obtained through UWF SS-OCTA for each eye. Statistical analysis, 10-fold cross-validation, and the random forest approach were employed for data processing.

Results

The degree of retinal microvascular damage in the diabetic retinopathy (DR) with the DN group was significantly greater than in the DR without DN group, as measured by SS-OCTA parameters. There were strong associations between perfusion density (PD) and DN diagnosis in both the T2DM population (r = -0.562 to -0.481, P < 0.001) and the DR population (r = -0.397 to -0.357, P < 0.001). The random forest model showed an average classification accuracy of 85.8442% for identifying DN patients based on perfusion density in the T2DM population and 82.5739% in the DR population.

Conclusions

Quantitative analysis of microvasculature reveals a correlation between DR and DN. UWF PD may serve as a significant and noninvasive biomarker for evaluating DN in patients through deep learning. AI-assisted SS-OCTA could be a rapid and reliable tool for screening DN.

Translational Relevance

We aim to study the pathological processes of DR and DN and determine the correspondence between their clinical and pathological manifestations to further clarify the potential of screening DN using AI-assisted UWF PD.

Choroidal structural changes in patients with early diabetic nephropathy

PURPOSE

To determine alterations of the choroidal thickness (CT) and the choroidal vascularity index (CVI) in patients with glomerular hyperfiltration, a marker of early diabetic nephropathy (DN).

METHODS

Twenty-two patients with type 2 diabetes (T2D) with glomerular hyperfiltration (early DN group) and 28 patients with T2D without DN (NDN group) were included in the study. Patients with diabetic retinopathy were excluded. Parameters including subfoveal CT, the subfoveal choroidal vascularity index (CVI), and total CVI were measured using spectral-domain enhanced depth imaging optical coherence tomography method.

RESULTS

The early DN group included 22 patients and the NDN group comprised 28 patients. The groups were similar in terms of age and sex (p>0.05). The CT values were statistically significantly lower in the early DN group than in the NDN group (p < 0.001). There was no significant difference between the early DN group and the NDN group in terms of total and subfoveal CVI (p>0.05).

CONCLUSION

The choroidal thickness decreased in patients with T2D with glomerular hyperfiltration, but there were no differences in CVI when they were compared with patients with T2D without DN.

Choroidal thickness in relation to urinary albumin excretion rate in type 2 diabetes mellitus without retinopathy

Background

To evaluate choroidal thickness (CT) in diabetic patients without diabetic retinopathy (DR) in relation to the urinary albumin excretion rate (UAER).

Methods

This is a prospective case-control study that included a consecutive sample of 120 patients with type 2 diabetes without clinically evident DR and a group of 60 matched healthy controls. Diabetic patients were included in two groups according to their UAER (normoalbuminuria and microalbuminuria). Complete ophthalmological examination was performed followed by optical coherence tomography (SD-OCT) for retinal and choroidal assessment. Twenty-four-hour urine samples were collected for UAER and blood samples for HbA1c and serum creatinine were obtained.

Results

The study included 180 eyes from 180 subjects in three groups. Patients with higher levels of albuminuria had a thinner choroid than normal controls, with decremental thinning as albuminuria progressed. Diabetics with normoalbuminuria showed no significant differences from controls. Choroidal thickness showed a significant moderate negative correlation with UAER (r  =  − 0.58, p  <  0.001). Multiple regression analyses for diabetic patients with microalbuminuria demonstrated that UAER is the most important determinant of subfoveal choroidal thickness (SFCT) (p  <  0.001).

Conclusions

Decreased CT was significantly correlated with UAER in diabetic patients without retinopathy and otherwise normal kidney functions. This decrease in thickness might be a predictor of DR.

An inadvertent issue of human retina exposure to endocrine disrupting chemicals: A safety assessment

Endocrine disrupting chemicals (EDCs) are a group of chemical compounds that present a considerable public health problem due to their pervasiveness and associations with chronic diseases. EDCs can interrupt the endocrine system and interfere with hormone homeostasis, leading to abnormalities in human physiology. Much attention has been focused on the adverse effects EDCs have on the reproductive system, neurogenesis, neuroendocrine system, and thyroid dysfunction. The eye is usually directly exposed to the surrounding environment; however, the influences of EDCs on the eye have received comparatively little attention. Ocular diseases, such as ocular surface diseases and retinal diseases, have been implicated in hormone deficiency or excess. Epidemiologic studies have shown that EDC exposure not only causes ocular surface disorders, such as dry eye, but also associates with visual deficits and retinopathy. EDCs can pass through the human blood-retinal barrier and enter the neural retina, and can then accumulate in the retina. The retina is an embryologic extension of the central nervous system, and is extremely sensitive and vulnerable to EDCs that could be passed across the placenta during critical periods of retinal development. Subtle alterations in the retinal development process usually result in profound immediate, long-term, and delayed effects late in life. This review, based on extensive literature survey, briefly summarizes the current knowledge about the impact of representative manufactured EDCs on retinal toxicity, including retinal structure alterations and dysfunction. We also highlight the potential mechanism of action of EDCs on the retina, and the predictive retinal models of EDC exposure.

Analysis of the Choroid and Its Relationship with the Outer Retina in Patients with Diabetes Mellitus Using Binarization Techniques Based on Spectral-Domain Optical Coherence Tomography

(1) Background: We aimed to reveal the relationship between the choroid and the outer retina with optical coherence tomography (OCT) in patients with diabetes mellitus (DM) with mild or no diabetic retinopathy (DR) in order to find early biomarkers for progressing retinopathy. (2) Methods: We performed a prospective study including 61 eyes of patients with type 1 or type 2 DM and 36 eyes of healthy controls. All subjects were imaged with Spectralis OCT. The choroid was assesseed using enhanced depth imaging OCT (EDI-OCT). Binarization of subfoveal choroidal images was done with public domain software, ImageJ (version 1.53a; National Institutes of Health, Bethesda, Maryland, USA). (3) Results: Luminal area, stromal area and total choroidal area were significantly decreased in diabetic patients compared to control: 0.23 ± 0.07 vs. 0.28 ± 0.08, p = 0.012; 0.08 ± 0.03 vs. 0.10 ± 0.04, p = 0.026; 0.31 ± 0.09 vs. 0.38 ± 0.11, p = 0.008. The thickness of retinal pigment epithelium (RPE) correlated positively with the choroidal vascularity index (CVI). The correlations between outer nuclear layer (ONL), photoreceptors (PR) and foveal choroidal thickness (FChT) were moderately negative. (4) Conclusion: Thicker RPE and a thinner PR layer may be assigned the role of early biomarkers signaling the conversion time to progressing retinopathy.

HEROIC: a 5-year observational cohort study aimed at identifying novel factors that drive diabetic kidney disease: rationale and study protocol

INTRODUCTION

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease worldwide and a major cause of premature mortality in diabetes mellitus (DM). While improvements in care have reduced the incidence of kidney disease among those with DM, the increasing prevalence of DM means that the number of patients worldwide with DKD is increasing. Improved understanding of the biology of DKD and identification of novel therapeutic targets may lead to new treatments. A major challenge to progress has been the heterogeneity of the DKD phenotype and renal progression. To investigate the heterogeneity of DKD we have set up The East and North London Diabetes Cohort (HEROIC) Study, a secondary care-based, multiethnic observational study of patients with biopsy-proven DKD. Our primary objective is to identify histological features of DKD associated with kidney endpoints in a cohort of patients diagnosed with type 1 and type 2 DM, proteinuria and kidney impairment.

METHODS AND ANALYSIS

HEROIC is a longitudinal observational study that aims to recruit 500 patients with DKD at high-risk of renal and cardiovascular events. Demographic, clinical and laboratory data will be collected and assessed annually for 5 years. Renal biopsy tissue will be collected and archived at recruitment. Blood and urine samples will be collected at baseline and during annual follow-up visits. Measured glomerular filtration rate (GFR), echocardiography, retinal optical coherence tomography angiography and kidney and cardiac MRI will be performed at baseline and twice more during follow-up. The study is 90% powered to detect an association between key histological and imaging parameters and a composite of death, renal replacement therapy or a 30% decline in estimated GFR.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Bloomsbury Research Ethics Committee (REC 18-LO-1921). Any patient identifiable data will be stored on a password-protected National Health Services N3 network with full audit trail. Anonymised imaging data will be stored in a ISO27001-certificated data warehouse.Results will be reported through peer-reviewed manuscripts and conferences and disseminated to participants, patients and the public using web-based and social media engagement tools as well as through public events.

Relationship Between Renal Function and Choroidal Thickness in Type 2 Diabetic Patients Detected by Swept-Source Optical Coherence Tomography

Purpose

To investigate the relationship between renal function and choroidal thickness (CT) in ocular treatment-naïve patients with diabetes mellitus using swept-source optical coherence tomography (SS-OCT).

Methods

This cross-sectional study recruited type 2 diabetes mellitus (T2DM) patients with no history of ocular treatment from communities in Guangzhou, China. The estimated glomerular filtration rates (eGFR) were calculated by using the Xiangya formula. The impaired renal function was defined as eGFR < 60 mL/(min 1.73 m²). The choroid was imaged by using an SS-OCT, and the macular CT was quantified automatically in Early Treatment Diabetic Retinopathy Study maps, and only data from one eye was used. Univariate and multivariate linear regression analyses were performed to explore the influence of eGFR on CT.

Results

A total of 1395 patients with T2DM were included in the final analysis. The CT of all macular regions were significantly thinner in patients with renal impairment (all P < 0.001). A significantly positive correlation was observed between the average CT and eGFR (β = 0.4; 95% confidence interval, 0.041-0.8; P = 0.029) independent of age, sex, and other potential confounding factors. After adjusting for other factors, a higher eGFR was also associated with higher CT values in the central field (P = 0.019) and in the outer superior (P = 0.047), inner superior (P = 0.018), inner inferior (P = 0.025), and inner temporal (P = 0.038) regions.

Conclusions

CT decreased in parallel with renal impairment in ocular treatment naïve diabetic patients, providing an accessible window for monitoring renal status.

Translational Relevance

Knowledge of association between retinal microvasculature and renal microcirculation would allow applying in both clinical and research settings.

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.

Choroidal Thickness and Hemoglobin A1c Levels in Patients with Type 2 Diabetes Mellitus

Purpose

The aim of this study was to assess the correlation of hemoglobin A1c (HbA1c) levels with choroidal thickness in patients with type 2 diabetes mellitus (DM) using spectral domain optical coherence tomography (SD-OCT).

Methods

In this prospective case series, 180 eyes from 90 patients with type 2 DM were classified into three study groups based on HbA1c values: group 1 included patients with good glycemic control (HbA1c ≤ 7%), group 2 included patients with moderate glycemic control (HbA1c between 7% and 8%), and group 3 included patients with poor glycemic control (HbA1c ≥ 8%). Additionally, 50 eyes from 25 non-diabetic subjects were enrolled to group 4 as a control group. Sub-foveal, nasal, and temporal choroidal thickness were measured and compared.

Results

Mean central, nasal, and temporal choroidal thicknesses in diabetic patients (247.80, 238.63, and 239.30 μm) were significantly less than non-diabetic healthy subjects (277.56, 262.92, and 266.32 μm). Additionally, mean central, nasal, and temporal choroidal thickness values in group 4 (277.56, 262.92, and 266.32 μm) were significantly greater than the corresponding values in group 2 (248.34, 237.55, and 236.45 μm) and group 3 (239.81, 234.62, and 233.94 μm), but was not significantly different from corresponding values in group 1 (259.46, 246.12, and 251.00 μm).

Conclusion

HbA1c values have a significant correlation with choroidal thickness in diabetic patients, and better glycemic control with HbA1c ≤ 7% may prevent choroidal thinning.

Changes in choroidal thickness and volume are related to urinary albumin excretion in type 2 diabetic patients without retinopathy

Purpose

To evaluate choroidal thickness and volume in patients with type 2 diabetes and microalbuminuria using spectral-domain optical coherence tomography.

Methods

We recruited 37 diabetic patients without diabetic retinopathy (18 normoalbuminuric and 19 microalbuminuric) and 21 healthy controls. Choroidal thickness and volume were mapped using the automated Early Treatment Diabetic Retinopathy Study grid and a topographic map of thickness was generated manually. Choroid was also measured at 10 locations under the fovea, temporally and nasally.

Results

Mean choroidal thickness and volume among patients with diabetes and microalbuminuria was reduced in all locations compared to controls (P<0.05). A sectoral decrease of choroidal thickness and volume was shown between microalbuminuric and normoalbuminuric groups.

Conclusion

Choroidal changes were present in type 2 diabetic patients before clinical development of retinopathy. Microalbuminuria was associated with a decrease in choroidal thickness and volume in diabetic patients without diabetic retinopathy.