Eye complications and markers of morbidity and mortality in long-term type 1 diabetes

Prognostic factors for the development and progression of proliferative diabetic retinopathy in people with diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is characterised by neurovascular degeneration as a result of chronic hyperglycaemia. Proliferative diabetic retinopathy (PDR) is the most serious complication of DR and can lead to total (central and peripheral) visual loss. PDR is characterised by the presence of abnormal new blood vessels, so-called "new vessels," at the optic disc (NVD) or elsewhere in the retina (NVE). PDR can progress to high-risk characteristics (HRC) PDR (HRC-PDR), which is defined by the presence of NVD more than one-fourth to one-third disc area in size plus vitreous haemorrhage or pre-retinal haemorrhage, or vitreous haemorrhage or pre-retinal haemorrhage obscuring more than one disc area. In severe cases, fibrovascular membranes grow over the retinal surface and tractional retinal detachment with sight loss can occur, despite treatment. Although most, if not all, individuals with diabetes will develop DR if they live long enough, only some progress to the sight-threatening PDR stage.  OBJECTIVES: To determine risk factors for the development of PDR and HRC-PDR in people with diabetes and DR.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 5), Ovid MEDLINE, and Ovid Embase. The date of the search was 27 May 2022. Additionally, the search was supplemented by screening reference lists of eligible articles. There were no restrictions to language or year of publication.  SELECTION CRITERIA: We included prospective or retrospective cohort studies and case-control longitudinal studies evaluating prognostic factors for the development and progression of PDR, in people who have not had previous treatment for DR. The target population consisted of adults (≥18 years of age) of any gender, sexual orientation, ethnicity, socioeconomic status, and geographical location, with non-proliferative diabetic retinopathy (NPDR) or PDR with less than HRC-PDR, diagnosed as per standard clinical practice. Two review authors independently screened titles and abstracts, and full-text articles, to determine eligibility; discrepancies were resolved through discussion. We considered prognostic factors measured at baseline and any other time points during the study and in any clinical setting. Outcomes were evaluated at three and eight years (± two years) or lifelong.  DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from included studies using a data extraction form that we developed and piloted prior to the data collection stage. We resolved any discrepancies through discussion. We used the Quality in Prognosis Studies (QUIPS) tool to assess risk of bias. We conducted meta-analyses in clinically relevant groups using a random-effects approach. We reported hazard ratios (HR), odds ratios (OR), and risk ratios (RR) separately for each available prognostic factor and outcome, stratified by different time points. Where possible, we meta-analysed adjusted prognostic factors. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.   MAIN RESULTS: We screened 6391 records. From these, we identified 59 studies (87 articles) as eligible for inclusion. Thirty-five were prospective cohort studies, 22 were retrospective studies, 18 of which were cohort and six were based on data from electronic registers, and two were retrospective case-control studies. Twenty-three studies evaluated participants with type 1 diabetes (T1D), 19 with type 2 diabetes (T2D), and 17 included mixed populations (T1D and T2D). Studies on T1D included between 39 and 3250 participants at baseline, followed up for one to 45 years. Studies on T2D included between 100 and 71,817 participants at baseline, followed up for one to 20 years. The studies on mixed populations of T1D and T2D ranged from 76 to 32,553 participants at baseline, followed up for four to 25 years.  We found evidence indicating that higher glycated haemoglobin (haemoglobin A1c (HbA1c)) levels (adjusted OR ranged from 1.11 (95% confidence interval (CI) 0.93 to 1.32) to 2.10 (95% CI 1.64 to 2.69) and more advanced stages of retinopathy (adjusted OR ranged from 1.38 (95% CI 1.29 to 1.48) to 12.40 (95% CI 5.31 to 28.98) are independent risk factors for the development of PDR in people with T1D and T2D. We rated the evidence for these factors as of moderate certainty because of moderate to high risk of bias in the studies.  There was also some evidence suggesting several markers for renal disease (for example, nephropathy (adjusted OR ranged from 1.58 (95% CI not reported) to 2.68 (2.09 to 3.42), and creatinine (adjusted meta-analysis HR 1.61 (95% CI 0.77 to 3.36)), and, in people with T1D, age at diagnosis of diabetes (< 12 years of age) (standardised regression estimate 1.62, 95% CI 1.06 to 2.48), increased triglyceride levels (adjusted RR 1.55, 95% CI 1.06 to 1.95), and larger retinal venular diameters (RR 4.28, 95% CI 1.50 to 12.19) may increase the risk of progression to PDR. The certainty of evidence for these factors, however, was low to very low, due to risk of bias in the included studies, inconsistency (lack of studies preventing the grading of consistency or variable outcomes), and imprecision (wide CIs). There was no substantial and consistent evidence to support duration of diabetes, systolic or diastolic blood pressure, total cholesterol, low- (LDL) and high- (HDL) density lipoproteins, gender, ethnicity, body mass index (BMI), socioeconomic status, or tobacco and alcohol consumption as being associated with incidence of PDR. There was insufficient evidence to evaluate prognostic factors associated with progression of PDR to HRC-PDR.  AUTHORS' CONCLUSIONS: Increased HbA1c is likely to be associated with progression to PDR; therefore, maintaining adequate glucose control throughout life, irrespective of stage of DR severity, may help to prevent progression to PDR and risk of its sight-threatening complications. Renal impairment in people with T1D or T2D, as well as younger age at diagnosis of diabetes mellitus (DM), increased triglyceride levels, and increased retinal venular diameters in people with T1D may also be associated with increased risk of progression to PDR. Given that more advanced DR severity is associated with higher risk of progression to PDR, the earlier the disease is identified, and the above systemic risk factors are controlled, the greater the chance of reducing the risk of PDR and saving sight.

Evaluation of the Central Effects of Systemic Lentiviral-Mediated Leptin Delivery in Streptozotocin-Induced Diabetic Rats

Type 1 diabetes (T1D) is characterized by hyperphagia, hyperglycemia and activation of the hypothalamic-pituitary-adrenal (HPA) axis. We have reported previously that daily leptin injections help to alleviate these symptoms. Therefore, we hypothesized that leptin gene therapy could help to normalize the neuroendocrine dysfunction seen in T1D. Adult male Sprague Dawley rats were injected i.v. with a lentiviral vector containing the leptin gene or green fluorescent protein. Ten days later, they were injected with the vehicle or streptozotocin (STZ). HPA function was assessed by measuring norepinephrine (NE) levels in the paraventricular nucleus (PVN) and serum corticosterone (CS). Treatment with the leptin lentiviral vector (Lepvv) increased leptin and insulin levels in non-diabetic rats, but not in diabetic animals. There was a significant reduction in blood glucose levels in diabetic rats due to Lepvv treatment. Both NE levels in the PVN and serum CS were reduced in diabetic rats treated with Lepvv. Results from this study provide evidence that leptin gene therapy in STZ-induced diabetic rats was able to partially normalize some of the neuroendocrine abnormalities, but studies with higher doses of the Lepvv are needed to develop this into a viable option for treating T1D.

NOD Mice-Good Model for T1D but Not Without Limitations

The nonobese diabetic (NOD) mouse model of type 1 diabetes (T1D) was discovered by coincidence in the 1980s and has since been widely used in the investigation of T1D and diabetic complications. The current in vivo study was originally designed to prospectively assess whether hyperglycemia onset is associated with physical destruction or functional impairment of beta cells under inflammatory insult during T1D progression in diabetes-prone female NOD mice. Prediabetic 16- to 20-wk-old NOD mice were transplanted with green fluorescent protein (GFP)-expressing reporter islets in the anterior chamber of the eye (ACE) that were monitored longitudinally, in addition to glycemia, with and without immune modulation using anti-CD3 monoclonal antibody therapy. However, there was an early and vigorous immune reaction against the GFP-expressing beta cells that lead to their premature destruction independent of autoimmune T1D development in progressor mice that eventually became hyperglycemic. This immune reaction also occurred in nonprogressor NOD recipients. These findings showed a previously unknown reaction of NOD mice to GFP that prevented achieving the original goals of this study but highlighted a new feature of the NOD mice that should be considered when designing experiments using this model in T1D research.

Type 1 diabetes mellitus impairs diurnal oscillations in murine extraorbital lacrimal glands

PURPOSE

People with diabetes are at high risk of lacrimal gland dysfunction, but the underlying mechanism is not well understood. In this study, we determined how type 1 diabetes mellitus (T1DM) influences circadian homeostasis of the murine extraorbital lacrimal glands (ELGs).

METHODS

A T1DM animal model was established by systemic streptozotocin injection in C57BL/6J mice. After 5 weeks, ELGs were collected at 3-h intervals over a 24-h circadian cycle. Total extracted RNA was subjected to high-throughput RNA sequencing, and rhythmic transcriptional data were evaluated using the Jonckheere-Terpstra-Kendall algorithm, Kyoto Encyclopedia of Genes and Genomes pathway analysis, Phase Set Enrichment Analysis, and time series cluster analysis to determine the phase, rhythmicity, and unique signature of the transcripts over temporally coordinated expression. Additionally, mass, cell size, histology, and tear secretion of the ELGs were evaluated.

RESULTS

T1DM globally altered the composition of the ELG transcriptome. Specifically, T1DM significantly reprogrammed the circadian transcriptomic profiles of normal ELGs and reorganized core clock machinery. Unique temporal and clustering enrichment pathways were also rewired by T1DM. Finally, normal daily rhythms of mass, cell size, and tear secretion of mouse ELGs were significantly impaired by streptozotocin-induced diabetes.

CONCLUSIONS

T1DM significantly reprograms the diurnal oscillations of the lacrimal glands and impairs their structure and tear secretion. This information may reveal potential targets for improving lacrimal gland dysfunction in patients with diabetes.

Mortality and causes of death in a population with blindness in Korea: A longitudinal follow-up study using a national sample cohort

The influence of visual impairment and blindness on the risk of mortality has been reported in diverse cohort studies. However, the results reported have varied from nonsignificant to significant associations. In the present study, we evaluated the influence of blindness on the risk of mortality from 2002 to 2013 using a longitudinal database with a national sample cohort provided by the Korean National Health Insurance Service. Of a total of 1,125,691 subjects, 1,279 subjects who were registered as blind were enrolled, and 5,116 control participants were matched at a 1:4 ratio for age, sex, income, region of residence, and medical histories of hypertension, diabetes mellitus and dyslipidemia. The life/death information contained in this dataset was used for the analysis; this information was originally recorded by the medical doctors on the death certificates of the participants. The percentage of total deaths during the mean follow-up period of 111.0 ± 41.6 months was 28.1% in the blindness group and 19.7% in the matched control group. The risk of mortality was significantly higher in the blindness group than in the control group according to the Cox proportional hazards model with additional adjustments for ischemic heart disease, stroke, and depression (adjusted hazard ratio [HR] of mortality = 1.54, 95% confidence interval [CI] = 1.37–1.74, P < 0.001). In the subgroup analyses, the adjusted HRs for mortality were significantly higher in the blindness group than in the control group regardless of age (young defined as <60 years old vs old defined as ≥60 years old) and sex. The percentage of death due to metabolic diseases and genitourinary diseases was higher in the blindness group than in the matched control group.

Association between Circulating B-Type Natriuretic Peptide and Diabetic Peripheral Neuropathy: A Cross-Sectional Study of a Chinese Type 2 Diabetic Population

Cardiovascular disease which is associated with cardiac dysfunction, usually measured with circulating levels of B-type natriuretic peptide (BNP), has been associated with incidence and progression of diabetic peripheral neuropathy (DPN). The potential relationship of circulating physiological levels of BNP with DPN, however, has not been reported. Circulating levels of BNP were measured in 258 patients with type 2 diabetes mellitus (T2DM), and participants were divided into a DPN group (n = 61) and no DPN group (n = 197). The relationship between circulating physiological levels of BNP and DPN and other parameters was analyzed. Circulating levels of BNP were significantly elevated in T2DM patients with DPN compared to those without (P = 0.001). Circulating levels of BNP were significantly and positively associated with systolic blood pressure (P = 0.035), neutrophil-to-lymphocyte ratio (P = 0.007), creatinine (P = 0.030), vibration perception threshold values (P = 0.021), and the prevalence of diabetic foot ulceration (P = 0.039), peripheral arterial disease (P = 0.013), DPN (P = 0.032), and diabetic nephropathy (P = 0.020) and negatively with lymphocyte count (P = 0.003) and ankle-brachial index (P = 0.038), irrespective of age, sex, and body mass index. Moreover, circulating levels of BNP was an independent decisive factor for the presence of DPN after multivariate adjustment (odds ratio, 1.044; 95% confidence interval, 1.006-1.084; P = 0.024). Additionally, the higher quartiles of circulating BNP were related significantly to an increased risk of DPN compared to the lowest quartile (P = 0.003). Last but most importantly, the analysis of receiver operating characteristic curves revealed that the best cutoff value for circulating levels of BNP to predict DPN was 15.18 pg/mL (sensitivity 78.7% and specificity 48.2%). These findings suggest that high circulating physiological levels of BNP may be associated with the development of DPN and may be a potential biomarker for DPN in patients with T2DM.

The Relationship of Retinal Vessel Geometric Characteristics to the Incidence and Progression of Diabetic Retinopathy

PURPOSE

To examine the relationships of retinal vessel geometric characteristics (RVGCs) to the incidence and progression of diabetic retinopathy (DR).

DESIGN

Observational, prospective cohort study.

PARTICIPANTS

Nine hundred ninety-six persons with type 1 diabetes mellitus (T1DM) and 1370 persons with type 2 diabetes mellitus (T2DM) seen at a baseline examination who were eligible for follow-up examinations at subsequent 5-year intervals. A total of 3846 person-interval data from these follow-up examinations are the basis for the analyses.

METHODS

Diabetic retinopathy and macular edema were assessed by grading of 30° stereoscopic color fundus photographs. Retinal vessel geometric characteristics were assessed using the Singapore I Vessel Assessment program from a digitized copy of 1 of the field 1 fundus photographs obtained at baseline and follow-up.

MAIN OUTCOME MEASURES

The 5-year incidence of any DR, progression of DR, and incidence of proliferative diabetic retinopathy (PDR) and clinically significant macular edema (CSME) in right eyes.

RESULTS

Incident DR occurred in 45%, progression in 32%, PDR in 10%, and CSME in 5%. While adjusting for glycated hemoglobin, duration of diabetes, and other factors, retinal arteriolar simple tortuosity was associated significantly with the incidence of any DR (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.01-1.35). Retinal venular branching angle was associated significantly with progression of DR (OR, 1.18; 95% CI, 1.03-1.36), retinal venular curvature tortuosity was associated significantly with the incidence of PDR (OR, 1.15; 95% CI, 1.01-1.30), and retinal venular branching angle (OR, 1.41; 95% CI, 1.10-1.82) was associated significantly with the incidence of CSME. There were no significant associations of other RVGCs with any of the DR outcomes in the full multivariate model. Inclusion of all possible RVGCs did not improve the predictive value of the models that already included retinal vessel diameter and baseline DR severity level.

CONCLUSIONS

Retinal vessel geometric characteristics of the retinal venules were associated with progression of DR; however, most of the RVGCs measured from digitized fundus photographs added little to the assessment of risk of incidence and progression of DR when other risk factors were considered in T1DM and T2DM.

The Different Faces of the Pancreatic Islet

Type 1 diabetes (T1D) patients who receive pancreatic islet transplant experience significant improvement in their quality-of-life. This comes primarily through improved control of blood sugar levels, restored awareness of hypoglycemia, and prevention of serious and potentially life-threatening diabetes-associated complications, such as kidney failure, heart and vascular disease, stroke, nerve damage, and blindness. Therefore, beta cell replacement through transplantation of isolated islets is an important option in the treatment of T1D. However, lasting success of this promising therapy depends on durable survival and efficacy of the transplanted islets, which are directly influenced by the islet isolation procedures. Thus, isolating pancreatic islets with consistent and reliable quality is critical in the clinical application of islet transplantation.Quality of isolated islets is important in pre-clinical studies as well, as efforts to advance and improve clinical outcomes of islet transplant therapy have relied heavily on animal models ranging from rodents, to pigs, to nonhuman primates. As a result, pancreatic islets have been isolated from these and other species and used in a variety of in vitro or in vivo applications for this and other research purposes. Protocols for islet isolation have been somewhat similar across species, especially, in mammals. However, given the increasing evidence about the distinct structural and functional features of human and mouse islets, using similar methods of islet isolation may contribute to inconsistencies in the islet quality, immunogenicity, and experimental outcomes. This may also contribute to the discrepancies commonly observed between pre-clinical findings and clinical outcomes. Therefore, it is prudent to consider the particular features of pancreatic islets from different species when optimizing islet isolation protocols.In this chapter, we explore the structural and functional features of pancreatic islets from mice, pigs, nonhuman primates, and humans because of their prevalent use in nonclinical, preclinical, and clinical applications.

Noninvasive Retinal Markers in Diabetic Retinopathy: Advancing from Bench towards Bedside

The retinal vascular system is the only part of the human body available for direct, in vivo inspection. Noninvasive retinal markers are important to identity patients in risk of sight-threatening diabetic retinopathy. Studies have correlated structural features like retinal vascular caliber and fractals with micro- and macrovascular dysfunction in diabetes. Likewise, the retinal metabolism can be evaluated by retinal oximetry, and higher retinal venular oxygen saturation has been demonstrated in patients with diabetic retinopathy. So far, most studies have been cross-sectional, but these can only disclose associations and are not able to separate cause from effect or to establish the predictive value of retinal vascular dysfunction with respect to long-term complications. Likewise, retinal markers have not been investigated as markers of treatment outcome in patients with proliferative diabetic retinopathy and diabetic macular edema. The Department of Ophthalmology at Odense University Hospital, Denmark, has a strong tradition of studying the retinal microvasculature in diabetic retinopathy. In the present paper, we demonstrate the importance of the retinal vasculature not only as predictors of long-term microvasculopathy but also as markers of treatment outcome in sight-threatening diabetic retinopathy in well-established population-based cohorts of patients with diabetes.

Association between microfibrillar-associated protein 4 (MFAP4) and micro- and macrovascular complications in long-term type 1 diabetes mellitus

AIMS

To evaluate microfibrillar-associated protein 4 (MFAP4) as a marker of micro- and macrovascular complications in patients with type 1 diabetes.

METHODS

This cross-sectional study included 203 persons with a long duration of type 1 diabetes from a population-based cohort ascertained in the former Funen County, Denmark. Detection of plasma-MFAP4 (pMFAP4) was performed by the AlphaLISA Technique. Diabetic retinopathy (DR) was graded in accordance with the Early Treatment Diabetic Retinopathy Study adaptation of the modified Airlie House classification. A monofilament test was used to test for neuropathy, and nephropathy was evaluated in a single spot urine sample. Data describing macrovascular disease were obtained from the Danish National Patient Register.

RESULTS

Median age and duration of diabetes were 58.7 and 43 years, respectively, and 61% were males. High levels of pMFAP4 were found in participants of old age, in women and in non-smokers (p < 0.05). In a multiple logistic regression model, patients with high levels of pMFAP4 were more likely to have diabetic neuropathy (OR 2.47 for quartile 4 versus quartile 1, 95% CI 1.01-6.03). No association was found between pMFAP4 and proliferative diabetic retinopathy, nephropathy or macrovascular disease.

CONCLUSIONS

No association between pMFAP4 and macrovascular vascular complications was found. However, high levels of pMFAP4 correlated independently with diabetic neuropathy. Further studies on the predictive value of increased circulating MFAP4 in diabetic neuropathy are warranted.

Inter-Eye Agreement in Measurement of Retinal Vascular Fractal Dimension in Patients with Type 1 Diabetes Mellitus

PURPOSE

To investigate inter-eye agreement in retinal vascular fractal dimension (FD) in patients with type 1 diabetes.

METHODS

In a cross-sectional study, both eyes were exained in 178 patients with type 1 diabetes. All vessels in a zone 0.5-2.0 disc diameters from the optic disc were traced and FD calculated with the box-counting method using SIVA-Fractal semiautomatic software. The modified Early Treatment Diabetic Retinopathy Study (ETDRS) scale was used to grade diabetic retinopathy (DR). Pitman's test of difference in variance was used to calculated inter-eye agreement in FD according to level of DR.

RESULTS

Mean age and duration of diabetes was 37.0 years and 29.5 years, respectively, and 49.4% of participants were male. Mean FD of right and left eyes was 1.4540 and 1.4472, respectively. FD did not differ between eyes in patients with no or non-proliferative DR (NPDR) in both eyes. This was true for patients with the same level of DR in both eyes (n = 74, p = 0.73), as well as for patients in which the ETDRS level of DR between the eyes differed by 1 (n = 43, p = 0.99) or more (n = 9, p = 0.53). In patients treated for proliferative DR in one eye, FD was significantly lower in this eye compared to the other (n = 10, p = 0.03).

CONCLUSION

FD did not differ significantly between the two eyes of patients with no DR or NPDR, despite differences in severity of DR.

HIF-1α SUMOylation affects the stability and transcriptional activity of HIF-1α in human lens epithelial cells

PURPOSE

High blood glucose can induce oxidative damage and result in diabetic cataract. Oxidative stress induces various signal pathways including HIF-1α transcriptional signal to attenuate the damage of lenses. Whether HIF-1α SUMOylation can increase the activation of HIF-1α or if high glucose can affect the SUMOylation of HIF-1α in cultured human lens epithelial cells (HLECs) is still unknown, as well as the function of HIF-1α SUMOylation in oxidative damage induced by high glucose in HLECs. In the present study, we examined SUMO and SUMO E3 (Cbx4 and PIASy) expression induced by high glucose, and investigated SUMO or SUMO E3 overexpression that enhanced HIF-1α SUMOylation in HLECs.

METHODS

SRA01/04 cells, one kind of human lens epithelial cell line, were addressed in media with 5.5 mmol/l (normal control group), 25 mmol/l (high glucose1 group) and 50 mmol/l (high glucose2 group) final glucose respectively. Expression of SUMO1 ~ 4, Cbx4, PIASy, HIF-1α, GLUT1, and VEGFA were detected in the mRNA and protein levels by RT-PCR and Western blot analysis. Protein expression localization and co-localization were examined by immunofluorescence and co-immunofluorescence. The effects of SUMO overexpression, SUMO E3 overexpression, and Proteasome inhibitor MG132 respectively on the stability and transcriptional activity of HIF-1α were analyzed by immunoblot.

RESULTS

High glucose treatment induced SUMO1-4 expression and enhanced the expression of Cbx4 and PIASy. It also increased the expression of HIF-1α, GLUT1, and VEGFA. The co-localization of HIF-1α and SUMO was mainly in the nucleus induced by high glucose. Further studies showed that SUMO overexpression or SUMO E3 overexpression could enhance HIF-1α stability and transcriptional activity in HLECs. Proteasome inhibitor MG132 protected the stability and transcriptional activity of HIF-1α in the SRA01/04 cells.

CONCLUSIONS

HIF-1α SUMOylation affected the stability and transcriptional activity of HIF-1α in cultured human lens epithelial cells; SUMO overexpression or SUMO E3 overexpression enhanced the expression of HIF-1α, which is involved in inhibiting cell apoptosis and protecting lens opacification, and presumably plays a key role in protecting lenses from diabetic cataract.

Cataract prevalence and prevention in Europe: a literature review

This literature review is aimed at the evaluation of the potential for cataract prevention in Europe. It was performed using PubMed with Mesh and free-text terms. Studies included were (i) performed on a population of Caucasian origin at an age range of 40-95 years, (ii) cataract was clinically verified, (iii) drug record of prescriptions, their indication, a record of every diagnosis, dosage and quantity of prescribed medicine were available, (iv) sample size >300 and (v) published between 1990 and 2009. The results of 29 articles were reviewed. Former [3.75 (2.26-6.21)] or current smoking [2.34 (1.07-5.15)], diabetes of duration >10 years [2.72 (1.72-4.28)], asthma or chronic bronchitis [2.04 (1.04-3.81)], and cardiovascular disease [1.96 (1.22-3.14)] increased the risk of cataract. Cataract was more common in patients taking chlorpromazine during ≥90 days with a dosage ≥300 mg [8.8 (3.1-25.1)] and corticosteroids >5 years [3.25 (1.39-7.58)] in a daily dose >1600 mg [1.69 (1.17-2.43)]. Intake of a multivitamin/mineral formulation [2.00 (1.35-2.98)] or corticosteroids [2.12 (1.93-2.33)] also increased the risk of cataract. Corticosteroids applied orally [3.25 (1.39-7.58)], parenteral [1.56 (1.34-1.82)] or inhalational [1.58 (1.46-1.71)] lead to cataract more frequently than those applied topically: nasal [1.33 (1.21-1.45)], ear [1.31 (1.19-1.45)] or skin [1.43 (1.36-1.50)]. Outpatient cataract surgery was negatively associated with total cataract surgery costs, and chlorpromazine, corticosteroids and multivitamin/mineral formation increase the risk of posterior subcapsular cataract dependent on dose, treatment application and duration. This review presented a comprehensive overview of specific and general cataract risk factors and an update on most recent experimental studies and randomized control trials directed at cataract prevention.

Screening and public health strategies for diabetic retinopathy in the Eastern Mediterranean region

Diabetic retinopathy (DR) is a complication of diabetes mellitus that can cause blindness. As the prevalence of diabetes increases globally and patients live longer, the cases of DR are increasing. To address the visual disabilities due to DR, screening of all diabetics is suggested for early detection. The rationale and principles of DR screening are discussed. Based on the available evidence, the magnitude of DR in countries in the Eastern Mediterranean region (EMR) is presented. Public health strategies to control visual disabilities due to DR are discussed. These include generating evidence for planning, implementing standard operating procedures, periodic DR screening, focusing on primary prevention of DR, strengthening DR management, health information management and retrieval systems for DR, rehabilitating DR visually disabled, using low-cost technologies, adopting a comprehensive approach by integrating DR care into the existing health systems, health promotion/counseling, and involving the community. Although adopting the public health approach for DR has been accepted as a priority by member countries of EMR, challenges in implementation remain. These include limitations in the public health approach for DR compared to that for cataract, few skilled workers, poor health systems and lack of motivation in affecting health-related lifestyle changes in diabetics.Visual disabilities due to DR are likely to increase in the coming years. An organized public health approach must be adopted and all stakeholders must work together to control severe visual disabilities due to DR.

Patterns of multimorbidity in the aged population. Results from the KORA-Age study

Multimorbidity is a common problem in aged populations with a wide range of individual and societal consequences. The objective of the study was to explore patterns of comorbidity and multimorbidity in an elderly population using different analytical approaches. Data were gathered from the population-based KORA-Age project, which included 4,127 persons aged 65–94 years living in the city of Augsburg and its two surrounding counties in Southern Germany. Information on the presence of 13 chronic conditions was collected in a standardized telephone interview and a self-administered questionnaire. Patterns of comorbidity and multimorbidity were analyzed using prevalence figures, logistic regression models and exploratory tetrachoric factor analysis. The prevalence of multimorbidity (≥2 diseases) was 58.6% in the total sample. Hypertension and diabetes (Odds Ratio [OR] 2.95, 99.58% confidence interval [CI] [2.19–3.96]), as well as hypertension and stroke (OR 2.00, 99.58% CI [1.26–3.16]) most often occurred in combination. This association was independent of age, sex and the presence of other conditions. Using factor analysis, we identified four patterns of multimorbidity: the first pattern includes cardiovascular and metabolic diseases, the second includes joint, liver, lung and eye diseases, the third covers mental and neurologic diseases and the fourth pattern includes gastrointestinal diseases and cancer. 44% of the persons were assigned to at least one of the four multimorbidity patterns; 14% could be assigned to both the cardiovascular/metabolic and the joint/liver/lung/eye pattern. Further common pairs were the mental/neurologic pattern combined with the cardiovascular/metabolic pattern (7.2%) or the joint/liver/lung/eye pattern (5.3%), respectively. Our results confirmed the existence of co-occurrence of certain diseases in elderly persons, which is not caused by chance. Some of the identified patterns of multimorbidity and their overlap may indicate common underlying pathological mechanisms.