Classification of diabetic retinopathy: Past, present and future

Diabetic retinopathy (DR) is a leading cause of visual impairment and blindness worldwide. Since DR was first recognized as an important complication of diabetes, there have been many attempts to accurately classify the severity and stages of disease. These historical classification systems evolved as understanding of disease pathophysiology improved, methods of imaging and assessing DR changed, and effective treatments were developed. Current DR classification systems are effective, and have been the basis of major research trials and clinical management guidelines for decades. However, with further new developments such as recognition of diabetic retinal neurodegeneration, new imaging platforms such as optical coherence tomography and ultra wide-field retinal imaging, artificial intelligence and new treatments, our current classification systems have significant limitations that need to be addressed. In this paper, we provide a historical review of different classification systems for DR, and discuss the limitations of our current classification systems in the context of new developments. We also review the implications of new developments in the field, to see how they might feature in a future, updated classification

Glaucoma Detection by Learning from Multiple Informatics Domains

We present a comprehensive and fully automatic glaucoma detection approach that uses machine learning techniques over multiple informatics domains, consisting of personal profile data, genetic data, and retinal image data. This approach, referred to as MKLclm, enriches the feature set of the multiple kernel learning (MKL) framework through the incorporation of classemes, which represent the outputs of multiple class-specific classifiers trained from the data of each informatics domain. We validate our MKLclm framework on a population- based dataset consisting of 2258 subjects, achieving an AUC of 94.9% ± 1.7% and a specificity of 88.5% ± 2.7% at 85% sensitivity, which is significantly better than the current clinical standard of care which uses intraocular pressure (IOP) for glaucoma detection. The experiments also demonstrate that MKLclm outperforms the standard SVM method using data from individual domains, as well as the traditional MKL method, showing that this deeper integration of data from different informatics domains can lead to significant gains in holistic glaucoma diagnosis and screening

Sleep Duration and Diabetic Kidney Disease

Aims: Abnormally short or long durations of sleep have been proposed as a risk factors for diabetes and its micro- and macro-vascular complications. However, the relationship between sleep duration and diabetic kidney disease (DKD) has not been well-characterized. Thus, we aimed to examine the association of sleep duration with DKD in two Asian populations.Methods: We included 1,258 persons (Malay, n = 403; Indian, n = 855) aged 40–80 years with diabetes from a population-based cross-sectional sample from Singapore. DKD was defined by low estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m2) and albuminuria (urinary albumin-to-creatinine ratio ≥30 mg/g, only measured in Indian participants). Self-reported habitual sleep duration was categorized into 4 categories: very short (<5 h), short (5–6.9 h), normal (7–8 h) and long (>8 h). The associations of sleep duration with low eGFR and albuminuria were analyzed using multivariable logistic regression models adjusted for multiple potential confounders (including classic risk factors such as HbA1c and hypertension).Results: In total, 268 (21.3%) participants had low eGFR, and 271 (34.7% in Indians) had albuminuria. The number (%) of individuals with very short, short, normal, and long durations of sleep were 117 (9.3%), 629 (50.0%), 429 (34.1%), and 83 (6.6%), respectively. Long sleep duration was associated with a higher odds of renal insufficiency compared to normal sleep duration (OR [95% CI]: 2.31 [1.27–4.19]) on multivariable analysis. Similarly, both long and very short durations of sleep were associated with higher odds of albuminuria (OR [95%]: 2.44 [1.36, 4.38] and 2.37 [1.25, 4.50], respectively) in Indian participants (where data on albuminuria were available).Conclusions: Our study suggests that abnormally short or long durations of sleep were associated with DKD, manifesting as either a reduced eGFR or increased albuminuria. However, further longitudinal data would be required for confirmation

Automated Tessellated Fundus Detection in Color Fundus Images

In this work, we propose an automated tessellated fundus detection method by utilizing texture features and color features. Color moments, Local Binary Patterns (LBP), and Histograms of Oriented Gradients (HOG) are extracted to represent the color fundus image. After feature extraction, a SVM classifier is trained to detect the tessellated fundus. Both linear and RBF kernels are applied and compared in this work. A dataset with 836 fundus images is built to evaluate the proposed method. For linear SVM, the mean accuracy of 98% is achieved, with sensitivity of 0.99 and specificity of 0.98. For RBF kernel, the mean accuracy is 97%, with sensitivity of 0.99 and specificity of 0.95. The detection results indicate that color features and texture features are able to describe the tessellated fundus

Plasma lipoprotein subfraction concentrations are associated with lipid metabolism and age-related macular degeneration

10.1194/jlr.M073684Journal of Lipid Research5891785-179

Obesity and the microvasculature

Overweight and obesity are thought to significantly influence a person's risk of cardiovascular disease, possibly via its effect on the microvasculature. Retinal vascular caliber is a surrogate marker of microvascular disease and a predictor of cardiovascular events. The aim of this systematic review and meta-analysis was to determine the association between body mass index (BMI) and retinal vascular caliber. Relevant studies were identified by searches of the MEDLINE and EMBASE databases from 1966 to August 2011. Standardized forms were used for data extraction. Among over 44,000 individuals, obese subjects had narrower arteriolar and wider venular calibers when compared with normal weight subjects, independent of conventional cardiovascular risk factors. In adults, a 1 kg/m(2) increase in BMI was associated with a difference of 0.07 μm [95% CI: -0.08; -0.06] in arteriolar caliber and 0.22 μm [95% CI: 0.21; 0.23] in venular caliber. Similar results were found for children. Higher BMI is associated with narrower retinal arteriolar and wider venular calibers. Further prospective studies are needed to examine whether a causative relationship between BMI and retinal microcirculation exists

Is Routine Pupil Dilation Safe among Asian Patients with Diabetes?

PURPOSE. To investigate the risk of acute angle closure (AAC), changes in intraocular pressure (IOP), and factors associated with these outcomes after routine pupil dilation in a cohort of Asian subjects with diabetes mellitus. METHODS. The study was a prospective observational case series of 1910 consecutive Asian subjects newly referred for assessment of diabetic retinopathy at a tertiary clinic. All subjects underwent routine pupil dilation unless there was a prior history of angle-closure glaucoma. Noncontact air-puff tonometry was used to assess IOP, which was measured by the same observer before and 1 hour after pupil dilation. Subjects were assessed for signs and symptoms of AAC before leaving the clinic, and their charts were also subsequently reviewed for revisits with AAC. RESULTS. Of the 1910 subjects who participated, none developed AAC. Sixty-nine subjects (3.6%, 95% CI: 2.8%-4.5%) showed an increase in IOP of Ն5 mm Hg in the either eye, 37 subjects (1.9%, 95% CI: 1.4%-2.6%) had a postdilation IOP Ͼ25 mm Hg in either eye, and only 10 subjects (0.52%, 95% CI: 0.25%-0.96%) had an increase in IOP Ն5 mm Hg and had a postdilation IOP Ͼ25 mm Hg in either eye. The level of predilation IOP and a known history of glaucoma were significant risk factors for a postdilation IOP Ն25 mm Hg. CONCLUSIONS. In this cohort of Asian persons with diabetes, the risk of AAC was insignificant after routine dilation of pupils for fundus examination. These data substantiate the safety of routine dilation of pupils in Asian patients with diabetes. (Invest Ophthalmol Vis Sci. 2009;50:4110 -4113

Retinal microvascular abnormalities and risk of renal failure in Asian populations

10.1371/journal.pone.0118076PLoS ONE102e011807

Is chronic kidney disease associated with diabetic retinopathy in Asian adults?

Background: Diabetic nephropathy (DN) is commonly associated with diabetic retinopathy (DR). Few studies have demonstrated that chronic kidney disease (CKD) is associated with DR. However, it is not clear if CKD in the absence of albuminuria is associated with DR. Methods: We included 301 participants with diabetes (Chinese, Malay and Indian ethnicity aged ≥24 years who participated in the Singapore Prospective Study Program (2003-2007). Retinal photographs taken from both eyes were graded for DR using the modified Airlie House Classification. We examined the association of CKD defined by low estimated glomerular filtration rate (eGFR) (&lt;60mL/min per 1.73m2, n=54), and albuminuria (urinary albumin-to-creatinine ratio ≥30, n = 116) with any-DR (n=99) in logistic regression models. We replicated this analysis in another independent population-based sample of Malay adults (n=265) with similar methodology in Singapore. Results: 41% of those with low-eGFR had normoalbuminuria. In separate models, while albuminuria was significantly associated with any-DR, low-eGFR was not significantly associated with any-DR. In a model combining both markers, compared to the referent group (normal-eGFR+normoalbuminuria), the odds ratio (OR) (95% confidence interval [CI]) of any-DR were: 2.33 (1.27-4.27) for normal-eGFR+albuminuria, 1.38 (0.49-3.91) for low-eGFR + normoalbuminuria, and 2.64 (1.05-6.63) for low-eGFR+albuminuria. Similar findings for any-DR were observed in the replication cohort of Malay persons (3.56 [1.49-8.54] for normal-eGFR+albuminuria, 1.69 (0.52-5.55) for low-eGFR+normoalbuminuria, 4.34 [1.68-11.24] for low-eGFR+albuminuria.Conclusion: We demonstrated that CKD is associated with DR only in the presence of albuminuria suggesting that CKD is more likely related to diabetes in the presence of albuminuria.</p