The 25-year incidence of visual impairment in type 1 diabetes mellitus the wisconsin epidemiologic study of diabetic retinopathy

Non-invasive skin autofluorescence as a screening method for diabetic retinopathy

Diabetic retinopathy (DR) is a public health problem and a common cause of blindness. It is diagnosed by fundus examination; however, this is a costly and time-consuming method. Non-invasive skin autofluorescence (SAF) may be an accessible, fast and simple alternative for screening and early diagnosis of DR. The aim of this study was to evaluate the accuracy of SAF as a screening method for DR. A systematic search of MEDLINE, Scopus, and Web of Science databases was performed. Random effects models for sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR), diagnostic odds ratio (dOR) value and 95% CIs were used to calculate test accuracy. In addition, hierarchical summary receiver operating characteristic curves (HSROC) were used to summarise the overall test performance. Four studies were included in the meta-analysis. Pooled sensitivity and specificity were 0.79 (95% CI 0.72-0.88; I2  = 0.0%) and 0.54 (95% CI 0.32-0.92; I2  = 97.0%), respectively. The dOR value for the diagnosis of DR using SAF was 5.11 (95% CI 1.81-14.48: I2  = 85.9%). The PRL was 2.17 (95% CI 0.62-7.64) and the NRL was 0.27 (95% CI 0.07-1.03). Heterogeneity was not relevant in sensitivity and considerable in specificity. The 95% confidence region of the HSROC included all studies. SAF as a screening test for DR shows sufficient accuracy for its use in clinical settings. SAF may be an appropriate method for DR screening, and further research is needed to recommend it as a diagnostic method.

Doppler ultrasound-based evaluation of hemodynamic changes in the ophthalmic artery and central retinal artery in patients with type 1 diabetes mellitus without retinopathy and with mild non-proliferative retinopathy

Aim

Determination of blood flow parameters in the ophthalmic artery and central retinal artery using Doppler ultrasound in patients with type 1 diabetes mellitus without fundus signs of diabetic retinopathy and with mild non-proliferative retinopathy.

Material and methods

To eliminate the impact of other systemic factors on vascular flow, the study enrolled a total of 80 patients with type 1 diabetes mellitus, aged between 18 and 45 years. The study participants did not have any diabetic complications or other systemic or ocular comorbidities. The control group comprised 81 healthy individuals within a similar age range. Color Doppler ultrasound examinations of the ophthalmic artery and central retinal artery were performed to evaluate selected blood flow parameters including peak systolic velocity, end-diastolic velocity, and resistance index.

Results

Patients with type 1 diabetes mellitus exhibited statistically significant decrease in both systolic and end-diastolic velocities in the central retinal artery, accompanied by an elevation in resistance index, compared to the control group. The study revealed differences in blood flow parameters between the patients without fundus changes and those exhibiting mild non-proliferative retinopathy. Specifically, patients with retinopathy showed a significant decrease in both systolic velocity and end-diastolic velocity in the central retinal artery. No differences were observed for the same parameters in the ophthalmic artery. When analyzing the patients' blood flow parameters in relation to the degree of diabetes control, as determined by glycated hemoglobin levels, a statistically significant reduction in systolic velocity was identified in both the ophthalmic and central retinal arteries in the group with poorly controlled diabetes.

Conclusions

Examination of the orbital vessels using Doppler ultrasound in patients with type 1 diabetes mellitus holds promise as an effective method for early detection of vascular abnormalities.

A Review on Diabetic Retinopathy

Diabetic retinopathy is a well-recognised microvascular complication of diabetes and is among the leading cause of blindness all over the world. Over the last decade, there have been advances in the diagnosis of diabetic retinopathy and diabetic macular edema. At the same time, newer therapies for the management of diabetic retinopathy have evolved. As a result of these advances, a decline in severe vision loss due to diabetes has been witnessed in some developing countries. However, there is a steady increase in the number of people affected with diabetes, and is expected to rise further in the coming years. Therefore, it is prudent to identify diabetic retinopathy, and timely intervention is needed to decrease the burden of severe vision loss. An effort has been made to review all the existing knowledge regarding diabetic retinopathy in this article and summarize the present treatment options for diabetic retinopathy.

Early diabetic eye damage: Comparing detection methods using diagnostic power

It is now clear that retinal neuropathy precedes classical microvascular retinopathy in diabetes. Therefore, tests that underpin useful new endpoints must provide high diagnostic power well before the onset of moderate diabetic retinopathy. Hence, we compare detection methods of early diabetic eye damage. We reviewed data from a range of functional and structural studies of early diabetic eye disease and computed standardized effect size as a measure of diagnostic power, allowing the studies to be compared quantitatively. We then derived minimum performance criteria for tests to provide useful clinical endpoints. This included the criteria that tests should be rapid and easy so that children with type 1 diabetes can be followed into adulthood with the same tests. We also defined attributes that lend test data to further improve performance using Machine/Deep Learning. Data from a new form of objective perimetry suggested that the criteria are achievable.

Automated segmentation of ultra-widefield fluorescein angiography of diabetic retinopathy using deep learning

BACKGROUND/AIMS

Retinal capillary non-perfusion (NP) and neovascularisation (NV) are two of the most important angiographic changes in diabetic retinopathy (DR). This study investigated the feasibility of using deep learning (DL) models to automatically segment NP and NV on ultra-widefield fluorescein angiography (UWFA) images from patients with DR.

METHODS

Retrospective cross-sectional chart review study. In total, 951 UWFA images were collected from patients with severe non-proliferative DR (NPDR) or proliferative DR (PDR). Each image was segmented and labelled for NP, NV, disc, background and outside areas. Using the labelled images, DL models were trained and validated (80%) using convolutional neural networks (CNNs) for automated segmentation and tested (20%) on test sets. Accuracy of each model and each label were assessed.

RESULTS

The best accuracy from CNN models for each label was 0.8208, 0.8338, 0.9801, 0.9253 and 0.9766 for NP, NV, disc, background and outside areas, respectively. The best Intersection over Union for each label was 0.6806, 0.5675, 0.7107, 0.8551 and 0.924 and mean mean boundary F1 score (BF score) was 0.6702, 0.8742, 0.9092, 0.8103 and 0.9006, respectively.

CONCLUSIONS

DL models can detect NV and NP as well as disc and outer margins on UWFA with good performance. This automated segmentation of important UWFA features will aid physicians in DR clinics and in overcoming grader subjectivity.

Short-term peripapillary structural and vascular changes following anti-VEGF vs. Dexamethasone intravitreal therapy in patients with DME

PURPOSE

To evaluate short-term peripapillary structural and vascular changes in DME after treatment with dexamethasone implant (DEX-I) and anti-VEGFs using OCT-A.

METHODS

Sixty-five patients with naïve center-involving DME were enrolled. 33 of sixty five patients (group 1) underwent with single DEX-I 0.7 mg (Ozurdex, Allergan, Inc., USA), 32 of sixty-five (group 2) underwent with intravitreal injection of aflibercept 0.5 mg (Eylea, Bayer, Genentech, San Francisco, USA). The OCT acquisition was completed at the following visits: (i) "T1 visit" corresponding to the intravitreal injection of DEX-I or aflibercept in patients with naïve center-involving DME (ii) "T2 visit" corresponding to the examination performed 2 weeks after intravitreal injection of aflibercept and 1 month after DEX-I. The parameters analyzed were: (i) RPC vasculature density (VD); (ii) peripapillary retinal nerve fiber layer (pRNFL) thickness, and (iii) intraocular pressure (IOP).

RESULTS

The RPC analysis showed a VD increase at T2 in both groups, although values did not reach statistical significance (48.12± 4.17 and 49.04 ± 4.23; P = 0.081 in Group 1 and 46.93± 3.16 and 47.17 ± 3.70; P = 0.087 in Group 2). Likewise, the pRNFL thickness and IOP fluctuations did not show statistically significant changes in in both groups among the different study visits.

CONCLUSIONS

After intravitreal injection (anti-VEGF or DEX-I), no significant short-term changes were found in peripapillary microvasculature, IOP and pRNFL thickness in diabetic eyes treated with anti-VEGF or DEX-I.

Associations between vision impairment and multimorbidity among older Chinese adults: results from the China health and retirement longitudinal study

BACKGROUND

Although several studies have reported the relationship between vision impairment (VI) and multimorbidity in high-income countries, this relationship has not been reported in low- and middle-income countries. This study aimed to explore the relationship between VI with multimorbidity and chronic conditions among the elderly Chinese population.

METHODS

The cross-sectional analysis was applied to data from the China Health and Retirement Longitudinal Study (CHARLS) in 2018. A total of 8,108 participants ≥ 60 years old were included, and 15 chronic conditions were used in this study. Logistic regression analysis was used to analyze the relationship between VI with multimorbidity and chronic conditions.

RESULTS

The prevalence of 15 chronic conditions and multimorbidity was higher among the elderly with VI than those without VI. After adjusting for demographic and socioeconomic confounders, 10 chronic conditions were associated with VI (all P < 0.05). Furthermore, positive association was observed between VI and one (odds ratio [OR]: 1.52; 95% confidence intervals [95%CI]: 1.16-2.00; P = 0.002), two (OR: 2.09; 95%CI: 1.61-2.71; P < 0.001), three (OR: 2.87; 95%CI: 2.22-3.72; P < 0.001), four (OR: 3.60; 95%CI: 2.77-4.69; P < 0.001), and five or more (OR: 5.53; 95%CI: 4.32-7.09; P < 0.001) chronic conditions, and the association increased as the number of chronic conditions (P for trend < 0.001). Sensitivity analysis stratified by gender, education, smoking status, and annual per capita household expenditure still found VI to be positively associated with multimorbidity.

CONCLUSIONS

For patients older than 60 years, VI was independently associated with multimorbidity and various chronic conditions. This result has important implications for healthcare resource plans and clinical practice, for example, increased diabetes and kidney function screening for patients with VI.

Revisiting Retinal Degeneration Hallmarks: Insights from Molecular Markers and Therapy Perspectives

Visual impairment and blindness are a growing public health problem as they reduce the life quality of millions of people. The management and treatment of these diseases represent scientific and therapeutic challenges because different cellular and molecular actors involved in the pathophysiology are still being identified. Visual system components, particularly retinal cells, are extremely sensitive to genetic or metabolic alterations, and immune responses activated by local insults contribute to biological events, culminating in vision loss and irreversible blindness. Several ocular diseases are linked to retinal cell loss, and some of them, such as retinitis pigmentosa, age-related macular degeneration, glaucoma, and diabetic retinopathy, are characterized by pathophysiological hallmarks that represent possibilities to study and develop novel treatments for retinal cell degeneration. Here, we present a compilation of revisited information on retinal degeneration, including pathophysiological and molecular features and biochemical hallmarks, and possible research directions for novel treatments to assist as a guide for innovative research. The knowledge expansion upon the mechanistic bases of the pathobiology of eye diseases, including information on complex interactions of genetic predisposition, chronic inflammation, and environmental and aging-related factors, will prompt the identification of new therapeutic strategies.

'I don`t need an eye check-up'. A qualitative study using a behavioural model to understand treatment-seeking behaviour of patients with sight threatening diabetic retinopathy (STDR) in India

Diabetic Retinopathy (DR) affects about 27% of patients with diabetes globally. According to the World Health Organization (WHO), DR is responsible for37 million cases of blindness worldwide. The SMART India study (October 2020-August 2021) documented the prevalence of diabetes, and DR in people40 years and above across ten Indian states and one Union Territory by conducting community screening. About 90% of people with sight threatening diabetic retinopathy (STDR) were referred from this screening study to eye hospitals for management, but failed to attend. This qualitative study, a component of the SMART India study, explored perceptions of referred patients regarding their susceptibility to eye related problems in diabetes and the benefits/barriers to seeking care. Perceived barriers from the viewpoint of ophthalmologists were also explored. Guided by the Health Beliefs Model (HBM), 20 semi structured interviews were carried out with consenting patients diagnosed with STDR. They included nine patients who had sought care recruited from eight eye hospitals across different states in India and eleven patients who did not seek care. Eleven ophthalmologists also participated. Four themes of analysis based on the HBM were, understanding of DR and its treatment, perceptions about susceptibility and severity, perceived barriers, perceived benefits and cues to action. Findings revealed poor understanding of the effects of diabetes on the eye contributing to low risk perception. Prohibitive costs of treatment, difficulties in accessing care services and poor social support were major barriers to seeking care. Ophthalmologists acknowledged that the absence of symptoms and the slow progressive nature of the disease deluded patients into thinking that they were fine. The study attests to the need for greater health literacy around diabetes, DR and STDR; for making treatment more affordable and accessible and for the development of effective patient education and communication strategies towards increasing compliance.

Azelaic acid and guanosine in tears improve discrimination of proliferative from non-proliferative diabetic retinopathy in type-2 diabetes patients: A tear metabolomics study

Background

Diabetic retinopathy (DR) is the microvascular ocular complication of diabetes mellitus (DM), which can lead to irreversible blindness and visual impairment if not properly treated. Tears can be collected non-invasively, and the compositions of tears could be the potential biomarkers for ocular diseases. Here we aimed to delineate the metabolomics signature in tears collected from Chinese type-2 DM patients with DR.

Methods

The metabolomics profiles of tear samples from 41 Chinese type-2 DM patients with DR and 21 non-diabetic subjects were determined by the untargeted liquid chromatography-mass spectrometry. The associated pathways of the differentially abundant metabolites were delineated, and the receiver operating characteristic curve analysis was conducted to identify the metabolites differentiating non-proliferative DR (NPDR) from proliferative DR (PDR).

Results

Total 14 differentially abundant metabolites were identified between total DR and non-diabetic subjects, and 17 differentially abundant metabolites were found between the NPDR and PDR subjects. Moreover, total 18 differentially abundant metabolites were identified between the NPDR and PDR subjects with stratification in DR duration and blood glucose level. d-Glutamine and d-glutamate metabolism was significantly highlighted in the PDR group as compared to the non-diabetic group. For the predictive performance, azelaic acid combined with guanosine achieved the area under receiver operating characteristic curve of 0.855 in the comparison between NPDR and PDR groups.

Conclusion

This study revealed the metabolomics changes in tear samples of DR patients. The metabolites in tears could be the potential biomarkers in the DR analysis.

Hyperglycemia Promotes Mitophagy and Thereby Mitigates Hyperglycemia-Induced Damage

The observation that diabetic retinopathy (DR) typically takes decades to develop suggests the existence of an endogenous system that protects from diabetes-induced damage. To investigate the existance of such a system, primary human retinal endothelial cells were cultured in either normal glucose (5 mmol/L) or high glucose (30 mmol/L; HG). Prolonged exposure to HG was beneficial instead of detrimental. Although tumor necrosis factor-α-induced expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 was unaffected after 1 day of HG, it waned as the exposure to HG was extended. Similarly, oxidative stress-induced death decreased with prolonged exposure to HG. Furthermore, mitochondrial functionality, which was compromised by 1 day of HG, was improved by 10 days of HG, and this change required increased clearance of damaged mitochondria (mitophagy). Finally, antagonizing mitochondrial dynamics compromised the cells' ability to endure HG: susceptibility to cell death increased, and basal barrier function and responsiveness to vascular endothelial growth factor deteriorated. These observations indicate the existence of an endogenous system that protects human retinal endothelial cells from the deleterious effects of HG. Hyperglycemia-induced mitochondrial adaptation is a plausible contributor to the mechanism responsible for the delayed onset of DR; loss of hyperglycemia-induced mitochondrial adaptation may set the stage for the development of DR.

The efficacy of micropulse laser combined with ranibizumab in diabetic macular edema treatment: study protocol for a randomized controlled trial

Background

At present, intraocular injection of anti-VEGF (vascular endothelial growth factor) drugs has replaced traditional laser therapy as the first-line treatment for DME (diabetic macular edema). However, ranibizumab, a commonly used anti-VEGF drug, is expensive and requires multiple intraocular injections. It places a heavy economic burden on patients with DME. Micropulse laser is safer than conventional laser and can reduce edema. Combined treatment with anti-VEGF may reduce the number of intraocular injections. This study will compare the efficacy of micropulse laser combined with ranibizumab treatment to ranibizumab monotherapy in the treatment of DME, providing a new regimen for future DME treatment.

Methods

This study is a prospective randomized double-blind controlled clinical trial (RCT) in patients with DME. After 1-year follow-up, visual acuity and macular edema regression will be compared between micropulse laser combined with ranibizumab group and ranibizumab monotherapy group to determine whether the efficacy of micropulse laser combined with ranibizumab treatment was not lower than that of ranibizumab monotherapy in the treatment of DME. Visual acuity measured by the ETDRS chart is the primary outcome measure. The secondary outcome measures are CMT (central macular thickness) measured by OCT (optical coherence tomography) and the number of injections of two groups. Changes in visual acuity and CMT of the two groups will be compared at 12-month follow-up. Before patients are recruited, we provide them with informed consent, in which we explain to them the purpose and process of the study.

Discussion

Micropulse laser combined with anti-VEGF drugs in the treatment of DME can reduce the number of intravitreal anti-VEGF injections, not only relieve the pain of the patients, but also ease the economic and psychological burden of patients, bringing great benefits. However, there is no treatment consensus for the parameters and specific methods of micropulse laser treatment for DME. There is a lack of clinical research data reference of micropulse laser combined with anti-VEGF therapy in clinical practice. This study intends to provide a new direction for clinical DME treatment and also provide a realistic consideration for the application of micropulse laser in DME treatment.

Trial registration

ClinicalTrials.gov NCT03690947. Registered on 1 October 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06593-2.

Changes in Visual Impairment due to Diabetic Retinopathy During 1980-2019 Based on Nationwide Register Data

OBJECTIVE

To evaluate changes in the incidence, prevalence, severity, and onset age of visual impairment (VI) due to diabetic retinopathy (DR) and compare these trends in the screening and treatment of diabetes during 40 years based on Finnish national register data.

RESEARCH DESIGN AND METHODS

We included people with VI with nonproliferative DR (NPDR; n = 2,490, 73% women) or proliferative DR (PDR; n = 2,026, 53% women) as the main diagnosis for VI during 1980-2019 in the Finnish Register of Visual Impairment. The number of patients with treated diabetes during 1986-2019 was obtained from the Social Insurance Institution of Finland registers based on reimbursed medication data.

RESULTS

The annual incidence of reported VI due to DR has decreased since it peaked in the 1990s: regarding NPDR, it decreased from 102.3 to 5.5 per 100,000 patients with treated diabetes between the 1990s and 2010s; regarding PDR, the respective change was from 39.9 to 7.4. The incidence of patients with diabetes treated for DR increased during this period. Annual prevalence of reported VI and differences between sexes steadily decreased in the 2000s and 2010s. The severity of reported VI has decreased, and the age at the onset of reported VI increased during the 40 years.

CONCLUSIONS

Prevalence and incidence of VI due to DR have dramatically decreased and shifted to older age during the 40 years despite the increasing prevalence of diabetes. These positive trends highlight the successful development and effectiveness of screening and therapies for diabetes and DR.

Mechanistic Pathogenesis of Endothelial Dysfunction in Diabetic Nephropathy and Retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are microvascular complications of diabetes. Microvascular endothelial cells are thought to be the major targets of hyperglycemic injury. In diabetic microvasculature, the intracellular hyperglycemia causes damages to the vascular endothelium, via multiple pathophysiological process consist of inflammation, endothelial cell crosstalk with podocytes/pericytes and exosomes. In addition, DN and DR diseases development are involved in several critical regulators including the cell adhesion molecules (CAMs), the vascular endothelial growth factor (VEGF) family and the Notch signal. The present review attempts to gain a deeper understanding of the pathogenesis complexities underlying the endothelial dysfunction in diabetes diabetic and retinopathy, contributing to the development of new mechanistic therapeutic strategies against diabetes-induced microvascular endothelial dysfunction.

Comparison of different methods of retinal imaging for the screening of diabetic retinopathy: a systematic review

BACKGROUND

Screening for diabetic retinopathy (DR) is recommended to detect sight-threatening complications prior to visual loss. Early Treatment Diabetic Retinopathy Study (ETDRS) seven standard field (7SF) retinal imaging has traditionally been regarded the gold standard for DR classification, but other methods are often preferred clinically. The purpose of this systematic review was to determine whether 7SF is the most optimal screening method for DR grading, or if similar results can be achieved by other methods using a smaller field of view (<7SF) or ultra-wide field (UWF) imaging.

METHODS

Based on Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, two independent reviewers initially identified 7167 publications in PubMed, Cochrane and Embase databases. Of these, 16 publications were included based on predefined inclusion criteria.

RESULTS

7SF was used as reference standard in 12 studies (compared with < 7SF in five studies and UWF in seven studies), and four studies compared other reference standards. Compared to 7SF, studies using < 7SF and UWF images both reported of similar agreement. A lower rate of ungradable images was reported for mydriatic and non-mydriatic UWF as compared to non-mydriatic < 7SF modalities.

CONCLUSION

Retinal imaging of <7SF and UWF both provide acceptable performance compared to 7SF. Given the time-consuming nature of the latter, these methods could be reasonable options in DR screening, even though a high number of ungradable images in non-mydriatic < 7SF may pose a clinical challenge.

Diabetic retinopathy as a potential marker of Parkinson's disease: a register-based cohort study

Neurodegeneration is an early event in the pathogenesis of diabetic retinopathy, and an association between diabetic retinopathy and Parkinson’s disease has been proposed. In this nationwide register-based cohort study, we investigated the prevalence and incidence of Parkinson’s disease among patients screened for diabetic retinopathy in a Danish population-based cohort. Cases (n = 173 568) above 50 years of age with diabetes included in the Danish Registry of Diabetic Retinopathy between 2013 and 2018 were matched 1:5 by gender and birth year with a control population without diabetes (n = 843 781). At index date, the prevalence of Parkinson’s disease was compared between cases and controls. To assess the longitudinal relationship between diabetic retinopathy and Parkinson’s disease, a multivariable Cox proportional hazard model was estimated. The prevalence of Parkinson’s disease was 0.28% and 0.44% among cases and controls, respectively. While diabetic retinopathy was not associated with present (adjusted odds ratio 0.93, 95% confidence interval 0.72–1.21) or incident Parkinson’s disease (adjusted hazard ratio 0.77, 95% confidence interval 0.56–1.05), cases with diabetes were in general less likely to have or to develop Parkinson’s disease compared to controls without diabetes (adjusted odds ratio 0.79, 95% confidence interval 0.71–0.87 and adjusted hazard ratio 0.88, 95% confidence interval 0.78–1.00). In a national cohort of more than 1 million persons, patients with diabetes were 21% and 12% were less likely to have prevalent and develop incident Parkinson’s disease, respectively, compared to an age- and gender-matched control population without diabetes. We found no indication for diabetic retinopathy as an independent risk factor for incident Parkinson’s disease.

Macular and peripapillary microvasculature after dexamethasone injection in diabetic macular edema

PURPOSE

To evaluate the microvascular changes in the macular and peripapillary area after intravitreal dexamethasone implant in diabetic macular edema (DME).

MATERIAL AND METHODS

We included 31 eyes of 31 patients treated with a single dose dexamethasone implant for DME. All subjects underwent swept-source optical coherence tomography (OCT) and OCT angiography imaging before (T0), and one month (T1), two months (T2), and four months (T4) after dexamethasone injection. The foveal avascular zone (FAZ) area of superficial and deep capillary plexus (SCP and DCP) was calculated by delineating the FAZ border using the measurement tool of the device. The vessel density (VD) of SCP and DCP and choriocapillaris (CC) in the macular and peripapillary area were automatically calculated.

RESULTS

There was an insignificant reduction in FAZ area measurements of SCP after dexamethasone injection in DME patients (p = 0.846). The FAZ area of DCP were significantly smaller compared to T0 measurements at T1, T2, and T4 (p = 0.013, p = 0.031, and p = 0.029, respectively). The mean average parafoveal VD measurements were significantly decreased after dexamethasone injection in SCP and DCP (p = 0.004, p = 0.005). The peripapillary VD in retinal capillary plexuses and choriocapillaris showed no significant difference after dexamethasone injection.

CONCLUSION

Intravitreal dexamethasone leads to a significant FAZ area decrease in DCP with a reduction in parafoveal VD measurements. In addition, no significant VD changes were observed in the peripapillary area after dexamethasone. These findings indicate that dexamethasone may improve macular ischemia with no significant effects on peripapillary microvasculature in DME patients.

Risk factors for having diabetic retinopathy at first screening in persons with type 1 diabetes diagnosed under 18 years of age

OBJECTIVE

To determine the risk factors for having diabetic retinopathy (DR) in children and young people (CYP) with type 1 diabetes (T1DM) at first screening.

METHODS

Records from the Diabetes Eye Screening Wales (DESW) service for people in Wales, UK, with T1DM diagnosed under age 18 years were combined with other electronic health record (EHR) data in the Secure Anonymised Information Linkage (SAIL) Databank. Data close to the screening date were collected, and risk factors derived from multivariate, multinomial logistic regression modelling.

RESULTS

Data from 4172 persons, with median (lower quartile, upper quartile) age 16.3 (13.0, 22.3) years and duration of diabetes 6.6 (2.3, 12.3) years were analysed. 62.6% (n = 2613) had no DR, 26.7% (n = 1112) background DR, and 10.7% (n = 447) had referable DR (RDR). No RDR was observed under 19 years of age. Factors associated with an increased risk of DR were diabetes duration, elevated HbA1c, and diastolic blood pressure. People diagnosed with T1DM at 12 years or older had an additional risk for each year they had diabetes compared to those diagnosed before age 12 controlling for the diabetes duration (odds ratios 1.23 and 1.34, respectively).

CONCLUSIONS

This study found that 37.4% of the study cohort had DR at first screening, the risk being greater the longer the duration of diabetes or higher the HbA1c and diastolic blood pressure. In addition, people diagnosed at 12 years of age or over were more likely to have DR with each additional year with diabetes.

Review of the management of sight-threatening diabetic retinopathy during pregnancy

Diabetes mellitus (DM) is a noncommunicable disease reaching epidemic proportions around the world. It affects younger individuals, including women of childbearing age. Diabetes can cause diabetic retinopathy (DR), which is potentially sight threatening when severe nonproliferative DR (NPDR), proliferative DR (PDR), or sight-threatening diabetic macular oedema (STDME) develops. Pregnancy is an independent risk factor for the progression of DR. Baseline DR at the onset of pregnancy is an important indicator of progression, with up to 10% of women with baseline NPDR progressing to PDR. Progression to sight-threatening DR (STDR) during pregnancy causes distress to the patient and often necessitates ocular treatment, which may have a systemic effect. Management includes prepregnancy counselling and, when possible, conventional treatment prior to pregnancy. During pregnancy, closer follow-up is required for those with a long duration of DM, poor baseline control of blood sugar and blood pressure, and worse DR, as these are risk factors for progression to STDR. Conventional treatment with anti-vascular endothelial growth factor agents for STDME can potentially lead to foetal loss. Treatment with laser photocoagulation may be preferred, and surgery under general anaesthesia should be avoided. This review provides a management plan for STDR from the perspective of practising ophthalmologists. A review of strategies for maintaining the eyesight of diabetic women with STDR with emphasis on prepregnancy counselling and planning, monitoring and safe treatment during pregnancy, and management of complications is presented.

PRE-RETINOPATHY OF TYPE 1 DIABETES IN THE CONTEXT OF FUNCTIONAL, STRUCTURAL AND MICROCIRCULATORY CHANGES IN THE MACULAR AREA

AIM

The authors assessed the development of intraocular changes in type 1 diabetes (T1DM) from the onset of the disease leading to diabetic retinopathy (DR). The quote: &#8220;There must be an intermediate stage between the physiological intraocular finding and the diabetic retinopathy itself &#8220;, (prof. Jan Vav&#345;inec).

METHODS

A two-year study (2018 and 2019) was conducted at the Department of Ophthalmology of the Teaching Hospital Kralovske Vinohrady in Prague (Czech Republic). There were 54 patients aged 17-42 years, the detection of T1DM ranged between the 1st and 14th year of life, with a duration of 12-35 years. Individual patients were always examined simultaneously by three methods: CS (contrast sensitivity), SD-OCT (spectral domain optical coherence tomography) and OCT-A (optical coherence tomography-angiography). We examined 106 eyes once and in a comprehensive manner.

RESULTS

We have shown that there is an intermediate stage between the physiological finding on the retina and DR, so-called diabetic pre-retinopathy (DpR). Subsequent redistribution of the observed into two DpR subgroups was derived from the size of the FAZ, either with its smaller area or with a larger area determining the microvascularity of the central area of the retina. The results of both other methods were assigned to these values. For SD-OCT, the depth of the fovea (the difference between the central retinal thickness and the total average retinal thickness) was determined, which was affected by the increased the macular cubature. In all patients it was on average 10.3 &#956;m3. The retina in the central area was significantly strengthened compared to the healthy population at the level of significance p 0,001. We divided the actual DpR into an image: DpR1 in 26.5 % of eyes - condition with an average shallower fovea only by 21.5 &#956;m below the level of the surrounding retina and an average narrower FAZ: 0.165 mm2 and with a more significant decrease in CS; DpR2 in 40.5 % of eyes - condition with average deeper fovea by 42 &#956;m, i.e., more significantly and average larger FAZ: 0.325 mm2 with lower decrease of CS. At the same time, other changes in microvascularity were noted, such as disorders in the sense of non-perfusion in the central part of the retina of various degrees. This finding differed significantly from changes in already established (non-proliferative) NPDR in 36 % of eyes, when a significant decrease in CS with normal visual acuity was found 4/4 ETDRS. Statistical differences in CS between DpR1 and DpR2 and NPDR were determined - always p 0.001. The average depth of the fovea was NPDR: 29.5 &#956;m. NPDR had the largest average FAZ: 0.56 mm2. Also significant were the most significant changes in non-perfusion and especially the presence of microaneurysms.

CONCLUSIONS

These three non - invasive methods helped to monitor the dynamics of the development of ocular changes in T1DM of better quality than the determination of visual acuity and ophthalmoscopic examination. Increased retinal volume induced hypoxia of visual cells with subsequent dual autoregulatory mechanism conditioning two types of diabetic pre-retinopathy before the onset of DR.

Socioeconomic disparity in global vision loss burden due to diabetic retinopathy: an analysis on time trends from 1990 to 2017

PURPOSE

To describe the trends of socioeconomic disparity in global vision loss burden associated with diabetic retinopathy (DR) based on prevalence and years lived with disability (YLDs).

METHODS

In the Global Burden of Disease (GBD) 2017 study, we extracted global, regional, national, and World Bank categorical epidemiological data in vision impairment by time and age. We searched the Human development index (HDI) from the Human Development Report. Pearson correlation, linear regression, and Kruskal-Wallis test were conducted to analyze the correlation between YLD rates and HDI. We used the Gini coefficient and concentration index to evaluate the socioeconomic inequality trendency.

RESULTS

The global and World Bank categorical prevalence and YLDs increased from 1990 to 2017, and rose with ageing. The age-standardized prevalence and YLD rates varied geographically and highest in the Eastern Mediterranean countries. Higher vision loss burden of DR was concentrated in countries with medium level of socioeconomic development, including lower/upper middle-income and medium/high-HDI countries. The Gini coefficient decreased from 0.572 in 1990 to 0.542 in 2017, showing the decreasing between-country inequality. The concentration index decreased from 0.153 in 2000 to 0.061 in 2017, showing the reducing socioeconomic-associated disparity.

CONCLUSION

The vision loss burden of DR increased in the past few decades, with a notable declining socioeconomic disparity since 2000. Our results highlight the necessity to provide more services to reduce the vision loss burden.

Decreasing prevalence of retinopathy in childhood-onset type 1 diabetes over the last decade: A comparison of two cohorts diagnosed 10 years apart

AIM

To ascertain whether the prevalence of retinopathy has declined over the last 2 decades in individuals with childhood-onset type 1 diabetes and whether this might be explained by changes in lifetime HbA1c.

MATERIALS AND METHODS

A multicentre, retrospective, observational study, comparing 128 subjects with diabetes onset in 2000-2003 assessed for retinopathy in 2016-2019, with a previous cohort of 115 individuals diagnosed in 1990-1993 and assessed for retinopathy in 2007-2009, was conducted. The two cohorts had both a similar diabetes duration and age at diagnosis. Retinal photographs were centrally graded. Lifetime HbA1c and its variability, estimated as the ratio between intrapersonal mean and standard deviation of HbA1c, were evaluated.

RESULTS

The prevalence of any retinopathy in the new and old cohort was 24.2% and 43.5% (P < .003), respectively, and that of severe retinopathy was 1.7% and 9.6% (P = .018). Lifetime HbA1c was lower in the new cohort (7.8% ± 0.8% vs. 8.1% ± 0.8%; P = .002) during all periods following the first 5 years after diagnosis. Patients without retinopathy in the two cohorts had similar levels of HbA1c. Compared with patients without retinopathy, those with retinopathy had higher lifetime HbA1c and long-term HbA1c variability. However, on multiple regression analysis, only lifetime HbA1c was independently associated with retinopathy (P = .0018).

CONCLUSIONS

The risk of developing retinopathy was nearly halved in children who developed type 1 diabetes in the new millennium compared with previous cohorts. These results confirm that maintaining the lowest possible levels of HbA1c throughout lifetime protects from diabetic retinopathy.

ETOILE: Real-World Evidence of 24 Months of Ranibizumab 0.5 mg in Patients with Visual Impairment Due to Diabetic Macular Edema

Purpose

To evaluate the real-world effectiveness of intravitreal ranibizumab 0.5 mg (Lucentis) in improving visual acuity (VA) in adults with decreased VA due to diabetic macular edema (DME).

Patients and Methods

Real-world prospective observational 24-month study. Ranibizumab-naïve patients (n=116) were enrolled, treated and followed up according to investigators’ usual procedures. Outcomes included change from baseline to month 24 in best-corrected VA (BCVA; primary outcome), central retinal thickness (CRT), treatment exposure and safety.

Results

Overall, 62.9% of patients completed the study per protocol, 68.6% completed the induction phase (first three injections one month apart). On average, patients had 12.5 ophthalmologist visits and 5.74 injections in year 1, decreasing to 4.6 visits and 1.94 injections in year 2. Mean baseline BCVA was 58.4 letters, mean gain at M24 was +6.08 letters (95% CI: 2.95, 9.21). Gains were higher for patients who completed induction, and for patients who did not switch treatment. Mean CRT improved by 149.17 μm at M24. There were no new safety signals. BCVA variation of ≥6 letters by M3 was predictive of BCVA gains at M24 (p=0.007), as was hypertension medication at baseline (p=0.022).

Conclusion

Real-world ranibizumab treatment improved VA in DME patients, despite fewer injections than recommended.

Blood-retinal barrier as a converging pivot in understanding the initiation and development of retinal diseases

Clinical ophthalmologists consider each retinal disease as a completely unique entity. However, various retinal diseases, such as uveitis, age-related macular degeneration, diabetic retinopathy, and primary open-angle glaucoma, share a number of common pathogenetic pathways. Whether a retinal disease initiates from direct injury to the blood-retinal barrier (BRB) or a defect/injury to retinal neurons or glia that impairs the BRB secondarily, the BRB is a pivotal point in determining the prognosis as self-limiting and recovering, or developing and progressing to a clinical phenotype. The present review summarizes our current knowledge on the physiology and cellular and molecular pathology of the BRB, which underlies its pivotal role in the initiation and development of common retinal diseases.

PATIENTS PRESENTING EMERGENTLY WITH PROLIFERATIVE DIABETIC RETINOPATHY: Follow-up and Factors Associated With Compliance

PURPOSE

To determine the rate of follow-up after emergent encounters for proliferative diabetic retinopathy and to identify patient or visit characteristics associated with follow-up compliance.

METHODS

A retrospective cohort study of patients presenting to an ophthalmic emergency department with active proliferative diabetic retinopathy between May 2014 and December 2016 was conducted. Demographic data and encounter data were gathered for each emergency department visit. Compliance with follow-up was defined as a completed clinic visit as scheduled after the emergency encounter.

RESULTS

A total of 590 emergency department encounters were included. The overall follow-up rate was 61.9%. Married patients and those with Public Health Trust insurance had increased odds of compliance (odds ratio [OR]: 1.507, P = 0.04; OR: 2.749, P < 0.0001). Patients with Medicaid had reduced odds (OR: 0.543, P = 0.004). Patients with longer emergency department encounters and longer intervals to follow-up had reduced odds (OR: 0.948, P = 0.001; OR of 0.941, P < 0.0001). The other characteristics were not significantly associated with follow-up compliance.

CONCLUSION

Patients who present emergently with active proliferative diabetic retinopathy are at high risk of following up noncompliance. Characteristics with significant effects on the odds of follow-up compliance include specific insurance payer, marriage status, length of visit, and interval to follow-up.

Inverse Cross-sectional and Longitudinal Relationships between Diabetic Retinopathy and Obstructive Sleep Apnea in Type 2 Diabetes

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Upregulation of long non-coding RNA SNHG16 promotes diabetes-related RMEC dysfunction via activating NF-κB and PI3K/AKT pathways

Diabetic retinopathy (DR) is a severe diabetes-induced eye disease, in which its pathological phenomena basically include abnormal proliferation, migration, and angiogenesis of microvascular endothelial cells in the retina. Long non-coding RNAs (lncRNAs) have been proven to be important regulators in various biological processes, but their participation in DR remains largely undiscovered. In the present study, we aimed to unveil the role of lncRNA small nucleolar RNA host gene 16 (SNHG16) in regulating the functions of human retinal microvascular endothelial cells (hRMECs) under a high-glucose (HG) condition. We found that SNHG16 expression was significantly upregulated in hRMECs treated with HG. Functionally, SNHG16 could facilitate hRMEC proliferation, migration, and angiogenesis. Moreover, SNHG16 was associated with nuclear factor κB (NF-κB) and phosphatidylinositol 3-kinase (PI3K)/AKT pathways. Mechanistically, SNHG16 could promote hRMEC dysfunction by sequestering microRNA (miR)-146a-5p and miR-7-5p to act as a competing endogenous RNA (ceRNA) with interleukin-1 receptor-associated kinase 1 (IRAK1) and insulin receptor substrate 1 (IRS1). In conclusion, our results illustrated the potential role of SNHG16 in facilitating hRMEC dysfunction under HG treatment, providing a novel approach for DR therapy.

Predictors for diabetic retinopathy progression-findings from nominal group technique and Evidence review

Objectives

Risk stratification is needed for patients referred to hospital eye services by Diabetic Eye Screening Programme UK. This requires a set of candidate predictors. The literature contains a large number of predictors. The objective of this research was to arrive at a small set of clinically important predictors for the outcome of the progression of diabetic retinopathy (DR). They need to be evidence based and readily available during the clinical consultation.

Methods and analysis

Initial list of predictors was obtained from a systematic review of prediction models. We sought the clinical expert opinion using a formal qualitative study design. A series of nominal group technique meetings to shorten the list and to rank the predictors for importance by voting were held with National Health Service hospital-based clinicians involved in caring for patients with DR in the UK. We then evaluated the evidence base for the selected predictors by critically appraising the evidence.

Results

The source list was presented at nominal group meetings (n=4), attended by 44 clinicians. Twenty-five predictors from the original list were ranked as important predictors and eight new predictors were proposed. Two additional predictors were retained after evidence check. Of these 35, 21 had robust supporting evidence in the literature condensed into a set of 19 predictors by categorising DR.

Conclusion

We identified a set of 19 clinically meaningful predictors of DR progression that can help stratify higher-risk patients referred to hospital eye services and should be considered in the development of an individual risk stratification model.

Study design

A qualitative study and evidence review.

Setting

Secondary eye care centres in North East, Midlands and South of England.

Circulating Metabolites and Lipids Are Associated to Diabetic Retinopathy in Individuals With Type 1 Diabetes

Omics-based methods may provide new markers associated to diabetic retinopathy (DR). We investigated a wide omics panel of metabolites and lipids related to DR in type 1 diabetes. Metabolomic analyses were performed using two-dimensional gas chromatography with time-of-flight mass spectrometry and lipidomic analyses using an ultra-high-performance liquid chromatography quadruple time-of-flight mass spectrometry method in 648 individuals with type 1 diabetes. Subjects were subdivided into no DR, mild nonproliferative DR (NPDR), moderate NPDR, proliferative DR, and proliferative DR with fibrosis. End points were any progression of DR, onset of DR, and progression from mild to severe DR tracked from standard ambulatory care and investigated using Cox models. The cohort consisted of 648 participants aged a mean of 54.4 ± 12.8 years, 55.5% were men, and follow-up was 5.1-5.5 years. Cross-sectionally, 2,4-dihydroxybutyric acid (DHBA), 3,4-DHBA, ribonic acid, ribitol, and the triglycerides 50:1 and 50:2 significantly correlated (P < 0.042) to DR stage. Longitudinally, higher 3,4-DHBA was a risk marker for progression of DR (n = 133) after adjustment (P = 0.033). We demonstrated multiple metabolites being positively correlated to a higher grade of DR in type 1 diabetes and several triglycerides being negatively correlated. Furthermore, higher 3,4-DHBA was an independent risk marker for progression of DR; however, confirmation is required.

Real-World Outcomes after 36-Month Treatment with Ranibizumab 0.5 mg in Patients with Visual Impairment due to Diabetic Macular Edema (BOREAL-DME)

PURPOSE

To assess the efficacy, safety, and follow-up of 36-month treatment with ranibizumab in patients with diabetic macular edema (DME) in real-life setting.

METHODS

This is a prospective phase 4 observational study. Between December 2013 and April 2015, 84 ophthalmologists enrolled a total of 290 adult patients initiating ranibizumab for visual impairment due to DME and treated them according to their routine practice. The primary outcome (mean change in best-corrected visual acuity [BCVA] after 12 months) was previously reported. Here, we present outcomes after 36 months of follow-up for BCVA and change in central subfield thickness (CSFT) and report how participating ophthalmologists treated DME over a 3-year period (number of visits and injections and evolution of treatment strategy).

RESULTS

Of the 290 patients enrolled, 187 (64.5%) completed the 36 months of the study (entire cohort). In the entire cohort, 97 patients were treated exclusively with ranibizumab throughout the study, and 90 patients switched to other intravitreal treatments. Mean BCVA was 64.2 (20.1) letters, representing a gain of +4.1 (19.9) letters from baseline to month 36 (M36). CSFT improved over the study, and by M36 had decreased by 127 (138) µm compared to baseline. Over the 36 months of follow-up, patients in the entire cohort paid their ophthalmologists a mean of 30.9 (12.2) visits and had a mean of 7.6 (5.2) any injections. Results for quality of life questionnaires NEI-VFQ25 and HUI-3 remained stable throughout the study. Multivariate analysis on the 145 patients with evaluable BCVA data at M36 found that male gender and milder baseline DME characteristics (BCVA ≥59 and CSFT <500 µm) were predictive factors for achieving a BCVA of ≥70 letters at M36. This study did not find any new safety signals, compared to the known profile of ranibizumab.

CONCLUSIONS

Gains in BCVA in this real-life study were lower than those observed in randomized clinical trials with ranibizumab, mainly due to undertreatment. Safety analysis of ranibizumab did not yield any new safety concerns.

New developments in angiography for the diagnosis and management of diabetic retinopathy

The most common microvascular complication of diabetes is diabetic retinopathy, the leading cause of blindness in adults of working age. Our understanding of the vascular changes in diabetic retinopathy was enhanced by the demonstration of fluorescein angiography (FA) in the human retina for the first time in 1961. It was subsequently integrated with digital fundoscopic imaging to become an invaluable technique in evaluation of the retinal vasculature. The recent development of OCT-angiography (OCT-A) has revolutionized the clinician's ability to examine the retinal vasculature without the need for injection of a contrast dye. By coupling OCT, which can provide noninvasive cross-sectional imaging of the central retina, with angiography in OCT-A, one can reveal retinal perfusion by allowing visualization of the depth-resolved retinal capillary plexus. OCT-A has allowed for more precise delineation of changes in the retinal microvasculature, specifically the alterations of retinal vasculature and loss of capillary perfusion from chronic microvascular occlusion in diabetic retinopathy.

Alterations in retinal arteriolar microvascular structure associate with higher treatment burden in patients with diabetic macular oedema: results from a 12-month prospective clinical trial

PURPOSE

This study was based on data from a 12-month prospective clinical trial and aimed to examine changes in retinal microvascular structure in eyes treated with intravitreal aflibercept in combination with focal/grid laser photocoagulation for diabetic macular oedema (DME).

METHODS

We included 32 treatment naïve eyes of 22 patients with centre involving DME. The treatment algorithm comprised a loading phase of three monthly injections of aflibercept and focal/grid laser photocoagulation [baseline (BL)-month 3 (M3)] followed by a pro re nata (PRN) aflibercept phase until month 12 (M12). Eyes were divided into groups with and without need for PRN treatment after loading. Parameters of retinal microvascular structure were measured in 45° optic disc centred fundus images at BL, M3 and M12 using a semi-automated software (VAMPIRE®, Vessel Assessment and Measurement Platform for Images of the Retina, Universities of Dundee and Edinburgh, UK).

RESULTS

A significant decrease in retinal arteriolar calibre was demonstrated at both M3 (-11.2 μm, p = 0.005) and M12 (-11.5 μm, p = 0.04) as compared to BL in eyes that needed PRN treatment during follow-up. In contrast, arteriolar calibre remained unchanged in eyes without need for PRN treatment (M3: -1.6 μm, p = 0.79 and M12: -7.0 μm, p = 0.22). For retinal venules, vessel calibre decreased both in eyes with and without need for PRN therapy at M3 (-9.5 μm, p = 0.01 and -11.6 μm, p = 0.01) as well as at M12 (-15.6 μm, p = 0.001 and -11.0 μm, p = 0.04).

CONCLUSION

Early changes in retinal arteriolar calibre are associated with an increased treatment burden during the first year of DME treatment.

Relationships among Retinal Nonperfusion, Neovascularization, and Vascular Endothelial Growth Factor Levels in Quiescent Proliferative Diabetic Retinopathy

Purpose: To investigate the relationships among the retinal nonperfusion (NP) area, neovascularization (NV) area, and aqueous humor vascular endothelial growth factor (VEGF) levels in quiescent proliferative diabetic retinopathy (PDR). Methods: Forty-seven eyes from 47 patients with treatment-naïve PDR that did not show macular edema or vitreous hemorrhage were enrolled. NP area, NV number, and NV area were quantitatively measured using ultra-widefield fluorescein angiography in an automated manner. Aqueous humor VEGF level was measured using a bead assay. Results: The NP areas of the total, posterior pole, peripheral retinae, and NV area positively correlated with each other (all p < 0.034). NV number correlated with total NP area, peripheral NP area, and NV area (all p ≤ 0.001). VEGF levels were significantly positively correlated with total, posterior polar, and peripheral NP areas and NV area (r = 0.575, 0.422, 0.558, and 0.362, respectively; all p ≤ 0.012). In eyes with NV in the disc area, the VEGF level was higher compare to eyes without NV in the disc area (208.89 ± 192.77 pg/mL vs. 103.34 ± 132.66, p = 0.010). A multiple linear regression model using NP area, NV area, and NVD demonstrated good prediction for VEGF level (R2 = 0.417, p < 0.001) and revealed a significant contribution of the peripheral NP area in predicting the VEGF level (β = 0.497, p = 0.002). Conclusions: Aqueous humor VEGF levels in quiescent PDR eyes were associated with NP and NV areas, which had positive correlations with each other. In addition, the NP area of the peripheral retina was the most important predictor of VEGF level.

Inhibition of β-elemene on the expressions of HIF-lα, VEGF and iNOS in diabetic rats model

AIM

To evaluate the effect of β-elemene on the expressions of hypoxia-inducible factor (HIF)-lα, vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) in a streptozotocin (STZ) induced diabetic Sprague-Dawley (SD) rat model.

METHODS

SD rats were administered an abdominal injection of STZ and induced to a diabetic model. After 6wk course of diabetes, the treatment groups were given β-elemene through periocular and intravitreous injection separately and the control groups were given blank emulsion injection. HE staining was used to observe the morphology of retina. The mRNA expressions of HIF-1α, VEGF and iNOS was assayed by real-time polymerase chain reaction (PCR) and the protein expression was measured by Western blot and immunocytochemistry methods.

RESULTS

The results indicated that the protein and mRNA expressions of HIF-1α, VEGF and iNOS after treated by β-elemene periocularly and intravitreally injections were all found to be reduced compared with the levels in the diabetic rats group (P<0.05). The inhibitory effect of intravitreal injection was more remarkable.

CONCLUSION

The results show β-elemene protect the retina of diabetic rats from high glucose damage by downregulating the expression of HIF-1α, VEGF and iNOS.

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.

Why are there gender inequalities in visual impairment?

BACKGROUND

In high-income countries, the prevalence of blindness and visual impairment is higher among women, regardless of age although the mechanisms that produce these gender inequalities are not well understood. The objectives of this study were to analyse gender inequalities in the prevalence of blindness and visual impairment, age of onset, diagnosed and undiagnosed status and related eye diseases among visually impaired individuals.

METHODS

Data were obtained from the 2008 Spanish Survey on 'Disability, Personal Autonomy and Dependency Situations' (n = 213 626) participants 360 blind (160 men and 200 women), and 5560 with some visual impairment (2025 men and 3535 women). The prevalence of blindness and visual impairment, age of onset of visual impairment and diagnosed and undiagnosed eye diseases was calculated. Hierarchical multiple logistic regression models were fit to test gender differences.

RESULTS

Women were more likely to report visual impairment (crude OR = 1.6 [95% CI: 1.56-1.74]). Prevalence of diagnosed cataract was higher among visually impaired women (crude OR = 1.4 [95% CI: 1.25-1.67]) whereas undiagnosed eye disease (crude OR = 0.7 [95% CI: 0.64-0.81]) or diagnosed glaucoma (aORsex = 0.8 [95% CI: 0.65-0.93]) were more frequent among visually impairment men. These associations were not explained by age or educational level.

CONCLUSIONS

Strong gender inequalities were observed, with a higher prevalence of visual impairment and related cataracts among women, which could be related to gender inequalities in access to health care, and undiagnosed eye disease and related glaucoma among men, which could be related to their gender socialization resulting in less frequent and effectively use of health care services.

Treatment of Diabetic Macular Edema

PURPOSE OF REVIEW

Diabetes mellitus is a global epidemic which is growing in prevalence, and diabetic macular edema (DME) is a leading cause of visual impairment among patients affected by this disease. Our objective is to review current and upcoming therapeutic approaches to DME.

RECENT FINDINGS

Once considered the gold standard in treatment of DME, focal/grid laser is now reserved mostly for non-center-involving DME, while anti-vascular endothelial growth factor (anti-VEGF) therapy has become the first-line treatment. However, suboptimal responders to anti-VEGF and the burden of frequent injections have stimulated the development of novel approaches. Corticosteroids can be effective in treating DME, but adverse effects such as intraocular pressure elevation and cataract formation must be considered. Emerging therapeutics and drug delivery systems in the pipeline offer exciting potential solutions to this vision-threatening disease. Multiple types of therapeutics targeting various pathways implicated in the pathogenesis of DME may help lessen the global burden of vision loss from diabetes.

Earliest Evidence of Preclinical Diabetic Retinopathy Revealed Using Optical Coherence Tomography Angiography Perfused Capillary Density

PURPOSE

To compare perfused capillary density (PCD) in diabetic patients and healthy controls using optical coherence tomography angiography (OCTA).

METHODS

Forty controls, 36 diabetic subjects without clinical retinopathy (NoDR), 38 with nonproliferative retinopathy (NPDR), and 38 with proliferative retinopathy (PDR) were imaged using spectral-domain optical coherence tomography. A 3 × 3-mm full-thickness parafoveal OCTA scan was obtained from each participant. Following manual delineation of the foveal avascular zone (FAZ), FAZ area, perimeter, and acircularity index were determined. Seven consecutive equidistant 200-μm-wide annular segments were drawn at increasing eccentricities from the FAZ margin. Annular PCD (%) was defined as perfused capillary area divided by the corresponding annulus area after subtraction of noncapillary blood vessel areas. Nonparametric Kruskal-Wallis testing with Bonferroni correction was performed in pairwise comparisons of group PCD values.

RESULTS

The NoDR group demonstrated consistently higher PCD compared to the control group in all 7 annuli, reaching statistical significance (36.6% ± 3.30% vs 33.6% ± 3.98%, P = .034) at the innermost annulus (FAZ margin to 200 μm out). The NPDR and PDR groups demonstrated progressively decreasing PCD. Differences in FAZ metrics between the NoDR and control groups did not reach statistical significance.

CONCLUSIONS

Relative to healthy controls, increased PCD values in the NoDR group likely represent an autoregulatory response to increased metabolic demand, while the decrease in PCD that follows in NPDR and PDR results largely from an incremental loss of capillary segments. These findings, consistent with previous studies, demonstrate the potential of OCTA as a clinical tool for earlier objective detection of preclinical diabetic retinopathy. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Ethanol Extract of Chinese Propolis Attenuates Early Diabetic Retinopathy by Protecting the Blood-Retinal Barrier in Streptozotocin-Induced Diabetic Rats

Propolis has been shown to reduce the level of blood glucose and suppress the histopathological changes in diabetics. However, it still remains unknown if propolis has a similar effect on diabetic retinopathy (DR). Our study aimed to evaluate the effect of the ethanol extract of Chinese propolis (EECP) on early DR in streptozotocin (STZ)-induced diabetic rats. EECP was given to diabetic rats by oral intubation for 12 weeks. The concentrations of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), malondialdehyde (MDA), reactive oxygen species (ROS), and reactive nitrogen species (RNS) were measured. Pathological examinations, including hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), and immunofluorescence, were also conducted to provide further evidence of EECP's effect on early DR. EECP was able to attenuate diabetes via directly decreasing the levels of FBG and HbA1c, which also resulted in the reduction of MDA, ROS, and RNS. Furthermore, EECP could protect against the damages of photoreceptor cells, as well as retinal thickening. And the inhibition of blood-retinal barrier (BRB) leakage was also observed in EECP-treated diabetic rats, along with the inhibition the loss of tight junction proteins (occludin, ZO-1). These results suggest that EECP has an ameliorating effect on early DR by inhibition of blood-retinal barrier breakdown. PRACTICAL APPLICATION: This study sheds light on the protective effect of the ethanol extract of Chinese propolis on early diabetic retinopathy and the molecular actions underlying the inhibition of blood-retinal barrier breakdown. Our study suggests that ethanol extract of Chinese propolis can be considered as a potential therapeutic agent in the treatment of early diabetic retinopathy.

Global trends in diabetes complications: a review of current evidence

In recent decades, large increases in diabetes prevalence have been demonstrated in virtually all regions of the world. The increase in the number of people with diabetes or with a longer duration of diabetes is likely to alter the disease profile in many populations around the globe, particularly due to a higher incidence of diabetes-specific complications, such as kidney failure and peripheral arterial disease. The epidemiology of other conditions frequently associated with diabetes, including infections and cardiovascular disease, may also change, with direct effects on quality of life, demands on health services and economic costs. The current understanding of the international burden of and variation in diabetes-related complications is poor. The available data suggest that rates of myocardial infarction, stroke and amputation are decreasing among people with diabetes, in parallel with declining mortality. However, these data predominantly come from studies in only a few high-income countries. Trends in other complications of diabetes, such as end-stage renal disease, retinopathy and cancer, are less well explored. In this review, we synthesise data from population-based studies on trends in diabetes complications, with the objectives of: (1) characterising recent and long-term trends in diabetes-related complications; (2) describing regional variation in the excess risk of complications, where possible; and (3) identifying and prioritising gaps for future surveillance and study.

Evidence-based Danish guidelines for screening of diabetic retinopathy

PURPOSE

Diabetic retinopathy (DR) is among the leading causes of visual loss in the working-age population. It is generally accepted that screening of DR is cost-effective and can detect DR before it becomes sight-threatening to allow timely treatment.

METHODS

A group of retinal specialists was formed by the Danish Ophthalmological Society with the aim to formulate contemporary evidence-based guidelines for screening of DR in order to implement these in the Danish screening system.

RESULTS

We hereby present evidence for DR-screening regarding (1) classification of DR, (2) examination techniques, (3) screening intervals and (4) automated screening. It is our recommendation that the International Clinical Retinopathy Disease Severity Scale should be used to classify DR. As a minimum, mydriatic two-field disc- and macular-centred images are required. In the case of suspected clinically significant diabetic macular oedema, supplementary optical coherence tomography can increase the diagnostic accuracy. There is solid evidence to support a flexible, individualized screening regimen. In particular, it is possible to prolong screening intervals to 24-48 months for patients with no or mild nonproliferative diabetic retinopathy (NPDR), but it is also possible to use extended intervals of 12-24 months for patients with moderate NPDR given that these are well-regulated regarding glycaemic control (HbA1c ≤ 53 mmol/mol) and blood pressure (≤130/80 mmHg). Automated screening of DR is encouraging but is not ready for implementation at present.

CONCLUSION

Danish evidenced-based guidelines for screening of DR support high-quality imaging and allow flexible, individualized screening intervals with a potential for extension to patients with low risk of DR progression.

The vasodilating effect of glucose differs among vessels at different branching level in the porcine retina ex vivo

Diabetic retinopathy is characterized by retinal lesions related to disturbances in retinal blood flow. The metabolic dysregulation in diabetes involves hyperglycemia which in both clinical and experimental studies has been shown to induce dilatation of larger retinal vessels, which has been suggested to be mediated by nitric oxide (NO). However, the effects of glucose on the diameter of smaller retinal vessels that are the site of development of diabetic retinopathy are unknown. Diameter changes in porcine retinal arterioles, pre-capillary arterioles and capillaries were studied ex vivo during acute changes in intraluminal glucose concentrations that mimicked changes in plasma glucose in diabetic patients. The experiments were repeated during blocking of NO-synthesis. Intravascular application of 2 mM glucose dilated arterioles and capillaries significantly, while 20 mM glucose dilated precapillary arterioles significantly. Intravascular application of 20 mM glucose dilated precapillary arterioles previously exposed to 2 mM glucose, while no significant diameter changes were observed after application of 2 mM glucose in vessels previously exposed to 20 mM glucose. No diameter changes were observed after application of 5.5 mM glucose in vessels previously exposed to both 2 mM and 20 mM glucose in either order. There was no significant difference between the diameter responses in the absence and presence of NO-synthesis blocker. Glucose induced dilatation of porcine precapillary arterioles ex vivo differs from the response in larger arterioles and capillaries, and the response is unaffected by the blocking of NO-synthesis. This may have implications for understanding the pathophysiology of diseases in the retinal microcirculation, such as diabetic retinopathy.

Angiogenic and Immunologic Proteins Identified by Deep Proteomic Profiling of Human Retinal and Choroidal Vascular Endothelial Cells: Potential Targets for New Biologic Drugs

PURPOSE

Diseases that involve retinal or choroidal vascular endothelial cells are leading causes of vision loss: age-related macular degeneration, retinal ischemic vasculopathies, and noninfectious posterior uveitis. Proteins differentially expressed by these endothelial cell populations are potential drug targets. We used deep proteomic profiling to define the molecular phenotype of human retinal and choroidal endothelial cells at the protein level.

METHODS

Retinal and choroidal vascular endothelial cells were separately isolated from 5 human eye pairs by selection on CD31. Total protein was extracted and digested, and peptide fractions were analyzed by reverse-phase liquid chromatography tandem mass spectrometry. Peptide sequences were assigned to fragment ion spectra, and proteins were inferred from openly accessible protein databases. Protein abundance was determined by spectral counting. Publicly available software packages were used to identify proteins that were differentially expressed between human retinal and choroidal endothelial cells, and to classify proteins that were highly abundant in each endothelial cell population.

RESULTS

Human retinal and/or choroidal vascular endothelial cells expressed 5042 nonredundant proteins. Setting the differential expression false discovery rate at 0.05, 498 proteins of 3454 quantifiable proteins (14.4%) with minimum mean spectral counts of 2.5 were differentially abundant in the 2 cell populations. Retinal and choroidal endothelial cells were enriched in angiogenic proteins, and retinal endothelial cells were also enriched in immunologic proteins.

CONCLUSIONS

This work describes the different protein expression profiles of human retinal and choroidal vascular endothelial cells, and provides multiple candidates for further study as novel treatments or drug targets for posterior eye diseases. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Type 1 Diabetic Subjects with Diabetic Retinopathy Show an Unfavorable Pattern of Fat Intake

Medical nutrition therapy is an important part of the management of type 1 diabetes mellitus (T1DM). Proper adherence to a healthy diet may have a favorable impact on diabetes management and its diabetic complications. Our aim was to assess differences in food and nutrient intake of type 1 diabetic patients with and without diabetic retinopathy (DR). This was a two-center, cross-sectional study in patients with T1DM, with and without DR. Subjects were recruited from the outpatient clinic of the two participating centers. A validated food frequency questionnaire was administered. A total of 103 T1DM patients with DR and 140 T1DM patient without DR were recruited. Subjects with DR showed a lower intake of total fat (p = 0.036) than that of their non-DR counterparts. DR was associated with increasing age (p = 0.004), hypertension (p < 0.001), and diabetes duration (p < 0.001), however there was a negative association with high educational level (p = 0.018). The multivariate-adjusted analysis showed that the intake of complex carbohydrates was positively related to the presence of DR (p = 0.031). In contrast, the intakes of total fat (p = 0.009), monounsaturated fatty acids (MUFAs) (p = 0.012), oleic acid (p = 0.012), and vitamin E (p = 0.006) were associated with the absence of DR. As conclusions, the intake of total MUFAs, oleic acid, and vitamin E is associated with a lower frequency of DR in patients with T1DM. These results suggest a potential protective effect of these lipid components for DR.

Diabetic retinopathy in type 1 diabetes patients in Western Norway

PURPOSE

To describe the prevalence of diabetic retinopathy (DR), associated risk factors and health-related quality of life (HRQoL) in a population-based cohort of patients with type 1 diabetes mellitus (DM1).

METHODS

All patients underwent a general and ophthalmic examination including seven-field stereo fundus photography for grading of DR and diabetic macular oedema (DMO). Kaplan-Meier survival analyses were performed to evaluate disease progression in relation to diabetes duration, age and year of diabetes onset. HRQoL and its association with DR were assessed by the Medical Outcomes Study Short Form 36 (SF-36) questionnaire.

RESULTS

A total of 237 DM1 patients were included. Mean age at inclusion was 34 years (range, 4-75 years), and mean diabetes duration was 19 years (range, 5 months-63 years). A total of 145 patients (61%) had DR. Sixty-two patients (26%) had mild, 39 (16%) moderate and 13 (5%) severe nonproliferative DR, while 31 (13%) had proliferative DR. The prevalence of DMO was 8%. The most important risk factors predicting severity of DR were diabetes duration (p < 0.0001) and HbA1c level (p < 0.0001). Neuropathy (p = 0.006), nephropathy (p = 0.004) and male gender (p = 0.02) were also significant predictors of DR. Compared to normative SF-36 data, there was a linear trend of decreasing HRQoL with increasing severity of DR that was statistically significant for the four physical dimension scores.

CONCLUSION

The prevalence of DR in DM1 was largely within the range of previous reports. Diabetes duration, HbA1c level, neuropathy, nephropathy and male gender were all significant predictors of DR severity. The patients with more severe DR had lower HRQoL.

Risk factors for development and progression of diabetic retinopathy in Dutch patients with type 1 diabetes mellitus

Purpose

To investigate risk factors for the development and progression of diabetic retinopathy (DR) and long‐term visual outcomes in Dutch patients with type 1 diabetes mellitus (T1DM).

Methods

Cumulative incidences were calculated for DR, vision‐threatening DR (VTDR), defined as (pre)proliferative DR and diabetic macular oedema, and best‐corrected visual acuity (BCVA) <0.5 and <0.3 at the most recent eye examination. The following factors were assessed: duration of diabetes, age of onset of T1DM, gender, mean HbA1c, HbA1c variability (defined as coefficient of variation of five separate HbA1c measurements), mean arterial blood pressure, body mass index, albuminuria and lipid profile. We used multivariable Cox regression models to identify factors associated with DR development and progression to VTDR.

Results

We found 25‐year cumulative incidences of 63% for DR, 21% for VTDR, 2% for BCVA <0.5, and 1% for BCVA <0.3. Mean HbA1c (HR 1.023, p < 0.001), HbA1c variability (HR 1.054, p < 0.001), age of onset of T1DM (HR 1.024, p < 0.001), HDL cholesterol (HR 0.502, p = 0.002) and total cholesterol (HR 1.210, p = 0.029) showed an independent association with faster development of any form of DR. The mean HbA1c (HR 1.023, p < 0.001) and the presence of albuminuria (HR 2.940, p = 0.028) were associated with faster progression to VTDR.

Conclusion

These data show relatively low cumulative incidences of DR, VTDR and visual impairment. Higher mean HbA1c, HbA1c variability, age of onset of T1DM and total cholesterol were independently associated with the risk of DR development, and a protective association was found for HDL cholesterol in subjects with T1DM. Mean HbA1c and presence of albuminuria were associated with progression of DR.

Peripheral capillary non-perfusion in treatment-naïve proliferative diabetic retinopathy associates with postoperative disease activity 6 months after panretinal photocoagulation

Background/aims

With the perspective to provide individualised panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR), we evaluated if retinal peripheral capillary non-perfusion (PCNP) and oximetry, as non-invasive markers of retinal metabolism and function, could predict disease activity 6 months after PRP.

Methods

We performed a prospective, interventional study of patients with treatment-naïve PDR. Retinal oximetry and ultra-widefield fluorescein angiography were performed at baseline (BL) and three (3M) and 6 months (6M) after PRP by a navigated laser system. At 6M follow-up, patients were divided according to disease activity: active or inactive.

Results

We included 33 eyes, and 69.6% were men. At BL, the median age and duration of diabetes (with IQRs) were 51.6±23.4 and 20.0±15.0 years. Haemoglobin A_1c was 63.0±17.0 mmol/mol and blood pressure was 152±37/82±24 mm Hg. At BL and M6, patients with postoperative disease activity (30.3.%, n=10) had a larger area with PCNP than those with inactive PDR (BL: 51%–75% vs 26%–50%, p=0.03; 6M: 51%–75% vs 26%–50%, p=0.03). The area of PCNP did not change from BL to 6M in either group (inactive PDR: p=0.38, active PDR: p=0.87). Changes in retinal oxygen saturation were not found to be clinical relevant.

Conclusion

We found the area of PCNP at all timepoints to be statistically larger in patients with active PDR 6 months after PRP treatment. Therefore, the area of PCNP, at baseline, may serve as a potential predictive marker for PDR activity after treatment.