The case for biennial retinopathy screening in children and adolescents

Cardiac Autonomic Nerve Dysfunction Predicts Incident Retinopathy and Early Kidney Dysfunction in Adolescents With Type 1 Diabetes

OBJECTIVE

Cardiac autonomic neuropathy (CAN) may contribute to vascular complications in diabetes. We hypothesized that adolescents with CAN are at greater risk of diabetic retinopathy and early kidney dysfunction.

RESEARCH DESIGN AND METHODS

In this prospective longitudinal study of 725 adolescents with type 1 diabetes without retinopathy and albuminuria at baseline, early CAN was defined as one or more abnormalities in seven heart rate tests derived from a 10-min electrocardiogram. Retinopathy was defined as the presence of one or more microaneurysms, early kidney dysfunction as an albumin excretion rate (AER) >7.5 μg/min, and albuminuria as an AER >20 μg/min. Multivariable generalized estimating equations were used to examine the association between CAN and retinopathy or early kidney dysfunction. Cox proportional hazards regression analysis was used to assess cumulative risks of incident retinopathy and albuminuria.

RESULTS

At baseline, the mean age of the sample was 13.6 ± 2.6 years, 52% were male, and mean diabetes duration was 6.1 ± 3.3 years. Over a median follow-up of 3.8 (interquartile range 2.2-7.5) years, the complication rate 27% for retinopathy, 16% for early kidney dysfunction, and 3% for albuminuria. The mean study HbA1c was 72.3 ± 16 mmol/mmol (8.6 ± 1.4%). CAN predicted incident retinopathy (odds ratio 2.0 [95% CI 1.4, 2.9]) and early kidney dysfunction (1.4 [1.0, 2.0]) after adjusting for HbA1c and diabetes duration. CAN also predicted retinopathy (hazard ratio 1.57 [95% CI 1.09, 2.26]) and albuminuria (2.30 [1.05, 5.04]) independently of HbA1c.

CONCLUSIONS

CAN predicted incident retinopathy and kidney dysfunction in adolescents with type 1 diabetes, likely reflecting autonomic microvascular dysregulation contributing to complications. Therefore, screening and interventions to reduce CAN may influence the risk of complications.

Sight-threatening retinopathy in nine adolescents with early onset type 1 diabetes

In adults, there has been a decline in the incidence of diabetic retinopathy (DR) associated with improvements in diabetes management. Data on incident severe DR in adolescents are sparse. In our established diabetes complications assessment service, we recorded nine cases of sight-threatening retinopathy in youth aged 15-17.9 years from 2017 to 2021. Proliferative retinopathy and clinically significant macular oedema were identified. The subjects were diagnosed with type 1 diabetes before the age of 10 years and had a history of poor glycaemic control (HbA1c 86-130 mmol/mol, 10%-15%). Five cases of retinopathy developed rapidly within 2.5 years of a previously normal retinal examination on seven-field stereoscopic retinal photography. Three adolescents required laser photocoagulation therapy. Two adolescents were diagnosed with retinopathy following improvement in diabetes control after being lost to medical follow-up and their retinopathy improved with improved glycaemic control. Thus, we support repeated retinal screening in adolescents with diabetes duration >10 years with suboptimal glycaemic control, even when initial retinal examination is normal, as retinopathy can progress rapidly during adolescence.

Risk factors associated with retinopathy in young people with type 1 diabetes in Bangladesh

Objectives

Diabetic retinopathy (DR) is the most common microvascular complications seen in children and adolescents with type 1 diabetes. The aim of this study was to evaluate the prevalence of retinopathy and its association with other risk factors in young people with type 1 diabetes.

Methods

This study was a cross-sectional study, which was done as part of the ongoing complication assessment in the paediatric diabetes clinic in BIRDEM (Bangladesh Institute of Research and Rehabilitation of Diabetes Endocrine and Metabolic Disorders), a tertiary care hospital. Children, adolescents and young adults with type 1 diabetes who were having diabetes duration >2 years were included in this study. Retinopathy was detected using fundal photography, and grading was done by National Screening Committee of UK by trained ophthalmologists.

Results

Diabetic retinopathy was observed in 44 (6.6%) patients. Majority (95.4%) of them had early diabetic retinopathy in the form of mild NPDR (nonproliferative diabetic retinopathy) (R1). Patients with retinopathy had higher HbA1c 9.6[8.4-12.3] vs 9.1 [7.9-10.8] (P = .013), longer duration of diabetes 7.6 [5.5-10.7] vs 6.0 [4.5-8.2] years (P = .001) and were older 21.5 [18.0-23.0] vs 18 [16.0-21.0] years (P = .0001) compared with those without retinopathy. On multivariate regression analysis, higher age and median HbA1c were significantly associated with DR.

Conclusions

Higher HbA1c was the only modifiable risk factor for development of DR in our study population. Early detection of DR with improvement of glycaemic control may reduce the risk of progression of severe stages of the disease.

Real-World Screening for Retinopathy in Youth With Type 1 Diabetes Using a Nonmydriatic Fundus Camera

OBJECTIVE

To assess the use of a portable retinal camera in diabetic retinopathy (DR) screening in multiple settings and the presence of associated risk factors among children, adolescents, and young adults with type 1 diabetes.

DESIGN AND METHODS

Five hundred youth with type 1 diabetes of at least 1 year's duration were recruited from clinics, diabetes camp, and a diabetes conference and underwent retinal imaging using a nonmydriatic fundus camera. Retinal characterization was performed remotely by a licensed ophthalmologist. Risk factors for DR development were evaluated by a patient-reported questionnaire and medical chart review.

RESULTS

Of the 500 recruited subjects aged 9-26 years (mean 14.9, SD 3.8), 10 cases of DR were identified (nine mild and one moderate nonproliferative DR) with 100% of images of gradable quality. The prevalence of DR was 2.04% (95% CI 0.78-3.29), at an average age of 20.2 years, with the youngest affected subject being 17.1 years of age. The rate of DR was higher, at 6.5%, with diabetes duration >10 years (95% CI 0.86-12.12, P = 0.0002). In subjects with DR, the average duration of diabetes was 12.1 years (SD 4.6, range 6.2-20.0), and in a subgroup of clinic-only subjects (n = 114), elevated blood pressure in the year before screening was associated with DR (P = 0.0068).

CONCLUSION

This study in a large cohort of subjects with type 1 diabetes demonstrates that older adolescents and young adults (>17 years) with longer disease duration (>6 years) are at risk for DR development, and screening using a portable retinal camera is feasible in clinics and other locations. Recent elevated blood pressure was a risk factor in an analyzed subgroup.

Early signs of microvascular complications in pediatric patients with short duration of type 1 diabetes mellitus seen in southeast Nigeria

Background

Clinically evident microvascular complications are rarely seen among children and adolescents with type 1 diabetes mellitus (T1DM), although early signs develop during childhood and accelerate during puberty.

Aim

The aim of this study was to determine the prevalence of early signs of microvascular complications in children and adolescents aged 9-19 years with a short duration of T1DM by screening for retinopathy and nephropathy.

Methods

A cross-sectional study and participants were consecutively enrolled from the Endocrinology Clinic at Federal Teaching Hospital, Abakaliki. Physical examination and mydriatic ophthalmoscopy were conducted. Three early morning spot urine specimens for albumin/creatinine ratio were estimated 3 months apart. Serum creatinine levels were estimated, and the glomerular filtration rate was calculated. Glycosylated hemoglobin (HbA1c) was determined.

Results

Twenty-four individuals participated, 15 (62.5%) were male and the mean age at diagnosis was 12.4 ± 2.3 years. The mean duration of diabetes was 23.8 ± 20.6 months. The mean HbA1c was 11.4%. Retinopathy was seen in 16.7%, whereas 33.3% had microalbuminuria. Blood pressure range was within the 50^th-90^th percentile for all the participants.

Conclusion

The study outcome demonstrated a high prevalence of early signs of microvascular complications such as retinopathy and nephropathy among youths with short duration of T1DM. Poor glycemic control, if not halted, is associated with early signs of microvascular complications which may become clinically evident; contrary to the belief that they are rare in childhood.

Screening for retinopathy in children with type 1 diabetes in Denmark

BACKGROUND/OBJECTIVE

Children with type 1 diabetes (T1D) are screened regularly for retinopathy with fundus photography to prevent visual impairment. According to Danish national guidelines, screening should take place at age 12, 15, and 18 years after minimum 3 years of diabetes. As glycemic control has improved, prevalence of retinopathy is expected to be decreased. The aim of this study is to investigate the prevalence, degree, and progression of retinopathy in children with T1D and to explore if screening at 12 years is currently indicated in Denmark.

METHODS

Data on all Danish children with onset of T1D from 2003 to 2013 (n = 2943) were collected from the "DanDiabKids" registry. For children with registered screenings (n = 2382), prevalence of retinopathy at 12, 15, and 18 years was determined. In children with retinopathy, subsequent screenings were studied to reveal if retinopathy was persistent or temporary.

RESULTS

Prevalence of retinopathy at 12, 15, and 18 years was 0.9%, 2.3%, and 3.1%, respectively. Minimal background retinopathy was seen in over 90% and 100% at 12 years. In available re-screenings, retinopathy resolved spontaneously in 87.5% of all cases and 100% of cases at 12 years.

CONCLUSIONS

The prevalence of retinopathy in Danish children with T1D was low. At 12 years, prevalence was 0.9% and exclusively minimal background retinopathy with 100% remission in re-screenings. Thus, screening at this age does not seem to have significant clinical relevance. We propose more individualized screening selection before the age of 15.

Associations between circulating inflammatory markers, diabetes type and complications in youth

BACKGROUND

Inflammation is implicated in the pathogenesis of diabetes and its complications in adults. Little is known about the relative contribution of inflammation in common types of diabetes in youth: type 1 diabetes (T1D), type 2 diabetes (T2D), and cystic fibrosis-related diabetes (CFRD). This study investigates inflammatory markers by diabetes type and complication status, and assesses indicators of inflammation and complications.

METHODS

A cross-sectional study of 134 T1D, 32 T2D, 32 CFRD and 48 subjects without diabetes (including 11 with CF and normal glucose tolerance) was undertaken. Inflammation was assessed by sE-selectin by ELISA, hsCRP by turbidimetry, WCC and ESR. Nephropathy was defined by albuminuria, autonomic neuropathy by heart rate variability, and peripheral neuropathy by vibration and thermal threshold testing and retinopathy by seven-field stereoscopic fundus photography. Descriptive statistics, parametric and non-parametric ANOVA and regression analyses were performed, with significance at P < .05.

RESULTS

Of 198 diabetic participants; 49% female, mean (SD) age, median diabetes duration and median HbA1c were 16 (2.5) and 6 (3-9) years, and 8.1 (6.9-9.3)%, respectively. All inflammatory markers were lower in T1D than in other diabetes groups (P < .05) but higher than in non-diabetic controls. T2D (n = 32) and CFRD (n = 32) subjects had comparable elevated levels of inflammation. Body mass index (BMI) was a strong independent explanatory variable of inflammation. In multivariate analysis, hsCRP and ESR were associated with complications in addition to HbA1c, BMI, and diastolic BP.

CONCLUSIONS

Circulating inflammatory markers are elevated in adolescents with diabetes, being higher and comparable in T2D and CFRD than in T1D. Inflammation is independently associated with diabetes complications, consistent with inflammation driving vascular pathology in diabetes.

High rates of ocular complications in a cohort of Haitian children and adolescents with diabetes

BACKGROUND

Ophthalmic complications of pediatric diabetes are rare, and rates are unknown in Haitian youth.

OBJECTIVES

To determine the prevalence and predictors of diabetic retinopathy (DR) and cataracts in a cohort of Haitian youth with insulin-treated diabetes.

METHODS

We performed a cross-sectional retrospective review of pediatric patients with diabetes from a pediatric chronic disease center in Haiti, from December 1, 2012 to November 1, 2016. Data collection included demographic and anthropometric information, total daily insulin dose and result of eye examination by a local ophthalmologist.

RESULTS

Of 67 patients (54% female, mean age at diagnosis 14.6 ± 3.9 years, mean diabetes duration 3.3 ± 3.0 years, mean HbA1c 84 ± 22 mmol/mol (9.8% ± 2.0%), mean current insulin requirement 0.49 ± 0.28 IU/kg/day), DR was diagnosed in 10/57 (18%) and cataracts in 10/62 (16%), at a mean age of 19.0 ± 4.3 and 19.1 ± 3.3 years, respectively. Diabetes duration was 4.9 ± 5.4 and 3.0 ± 1.5 years at the time of diagnosis of DR and cataracts, respectively. Age at complication, insulin requirement, sex, body mass index, family history, mean HbA1c and diabetes duration were not significant predictors of an ocular complication.

CONCLUSIONS

In this cohort of Haitian youth, DR and cataracts occur prematurely. Low-insulin requirements years after diagnosis, possibly allowing for prolonged undetected hyperglycemia prediagnosis, may explain complication risk. The phenotypes of diabetes in pediatric populations of African ancestry may be distinct. Ophthalmologic evaluation should possibly start at diagnosis, and screening guidelines may need to be adapted.

Prevalence of diabetic retinopathy in children and young people living with diabetes: protocol for a systematic review

INTRODUCTION

The frequency of diabetes mellitus in childhood is increasing. Thus, more children and young people are at risk of developing diabetic retinopathy and diabetes related visual impairment. However, there is no consensus on optimal screening strategies for the paediatric population reflecting the lack of clarity about the current burden of disease in this group. We aim to estimate the prevalence of diabetic retinopathy in children and young people living with types 1 or 2 diabetes, and to investigate potential sources of heterogeneity in this figure so as to inform screening strategies for this population.

METHODS AND ANALYSIS

PubMed and EMBASE will be searched from 1995 to 2016 using the OvidSP platform with no language restriction. Additionally, manual review of the references lists of included articles will be conducted. Two investigators will independently screen titles and abstracts for potential eligibility. Studies which report prevalence of diabetic retinopathy among general populations of children and young people with types 1 or 2 diabetes will be included. Pooled prevalence estimates of diabetic retinopathy reported in studies with sample size greater than 200 participants will be calculated by the random effect model. Forest plots will be used to summarise individual and pooled estimates of the prevalence. Heterogeneity between studies will be assessed using the I2 statistic and explored through meta-regressions and subgroup analyses if the necessary data are available.

ETHICS AND DISSEMINATION

Ethics approval is not required as this is a review of anonymised published data. We will report the findings of this systematic review in a peer-reviewed journal, and share it with the relevant professionals including health authorities through our Diabetic Eye disease in Childhood Study collaborative network.

CLINICAL TRAIL REGISTRATION

PROSPERO (CRD42017067178).

Ocular manifestations of Type 1 diabetes mellitus in pediatric population

Context:

To evaluate the necessity of ocular screening in Type 1 diabetes mellitus (DM).

Aims:

This study aims to investigate the diabetes-related ocular changes according to the glycosylated hemoglobin (HbA1c) level and duration of diabetes in children and compare the results with nondiabetic healthy children.

Settings and Design:

Observational cross-sectional study designed by ophthalmology and pediatric endocrinology clinics.

Subjects and Methods:

Forty-two children with Type 1 DM, 42 healthy gender- and age-matched children as controls were enrolled. All patients underwent ophthalmic and physical examination, with a review of medical history and current medication. HbA1c level, best corrected visual acuity, intraocular pressure (IOP), central corneal thickness (CCT), tear break-up time (BUT), Schirmer test, dilated fundus examination findings, central retinal thickness (CRT), and total macular volume (TMV) measurements were noted.

Statistical Analysis:

Descriptive statistics, Student's t-test, Mann–Whitney U-test, Chi-square test for comparison of the group parameters and correlation analyses (Spearman analysis) were performed with SPSS statistical software 17.0 (SPSS Inc., Chicago, IL, USA).

Results:

Type 1 DM group exhibited significantly reduced Schirmer test, increased IOP and decreased retinal thickness relative to the age-matched control group (P < 0.05) but no statistically significant difference was found for the BUT (P = 0.182) and for the CCT (P = 0.495). The correlations between the age, duration, HbA1c and IOP, BUT, Schirmer test, TMV, CRT measurements did not reach statistical significance.

Conclusions:

More frequent screening may be needed for complications, including neuropathy-related dry eye syndrome, IOP changes, and diabetic retinopathy in children with Type 1 DM.

Prevalence and risk factors for diabetic retinopathy in a hospital-based population of Australian children and adolescents with type 1 diabetes

BACKGROUND

The aim of this study was to investigate the prevalence of, and traditional and emerging risk factors associated with, retinopathy in a hospital-based population of Australian children and adolescents with type 1 diabetes.

METHODS

This was a cross-sectional study of 483 children and adolescents with type 1 diabetes. Medical files were audited to collect all relevant clinical data. Diabetic retinopathy was assessed from colour retinal images by an ophthalmologist.

RESULTS

Diabetic retinopathy was observed in 11 (2.3%) participants. Logistic regression revealed that the principal components analysis derived risk profile of: higher serum creatinine, older age, higher systolic blood pressures, higher body mass index, abnormal estimated glomerular filtration rate (eGFR) (<59 mL/min), lower high density lipoproteins (HDL) cholesterol, higher serum sodium, longer duration of diabetes and narrower retinal arteriolar calibre was associated with diabetic retinopathy (ExpB=2.60, 95% CI 1.36/4.96, p=0.004).

CONCLUSIONS

These results support the concept that the pathogenesis of diabetic retinopathy is likely due to the combined influence of various risk factors, many already identified.

Natural history of retinopathy in children and young people with type 1 diabetes

PurposeTo describe the prevalence and natural history of retinopathy in a cohort of children and young people with type 1 diabetes attending a tertiary hospital diabetes clinic.MethodsWe analysed retinopathy screening data from 2008 to 2010 on all eligible children using the 'Twinkle' diabetes database and the regional retinal screening database.ResultsA total of 88% (149/169) of eligible children were screened in 2008, median age 14 years, 52% male. The prevalence of retinopathy was 19.5% (30/149). All children had background retinopathy grade R1. There was significant difference in median (range) duration of diabetes, 7.7 years (0.6-13.7) vs 5 years (0.2-12.5) (P<0.001) and median (range) HbA1C, 9.1% (7.2-14) vs 8.6% (5.6-13.1) (P=0.02), between the groups with and without retinopathy. At 2- years follow-up, 12/30 (40%) had unchanged retinopathy grade R1, 10/30 (33.3%) showed resolution of changes (R0), 1/30 progressed to maculopathy, and 7/30 had no follow-up data. Median (range) HbA1C in 2008 and 2010 for the groups with stable vs resolved changes was similar, 9.1% (7.2-14.0) and 9.2% (7-14.0) vs 9.5% (7.8-14.0) and 9.2% (8.7-14.0). Of the 119 without retinopathy in 2008, 27 (22.5%) had developed retinopathy within 2 years, including 1 with pre-proliferative retinopathy and 1 with maculopathy. There was no significant difference in HbA1c between those who progressed to retinopathy (8.7% (7.1-13.1)) (8.7% (7.1-13.1)), and those who did not (8.6% (6.3-12.2)).ConclusionsPrevalence of background retinopathy in our cohort was comparable to the previously published reports, with higher HbA1c and longer duration of diabetes being significant risk factors. On short-term follow-up, Grade 1 retinopathy is likely to resolve in a third of patients and remain unchanged in just over a third.

Ocular Complications in Children with Diabetes Mellitus

PURPOSE

The effectiveness of annual eye examinations in diabetic children is unclear. We sought to determine the prevalence and onset of ocular pathology in children with diabetes mellitus (DM), identify risk factors for ocular disease, and recommend a screening regimen for asymptomatic children.

DESIGN

Retrospective, consecutive cohort study.

PARTICIPANTS

Children aged less than 18 years with type 1 or 2 DM examined over a 4-year period.

METHODS

All children underwent a complete eye examination, including dilated fundoscopy and cycloplegic refraction. A literature review was performed, identifying the youngest reported age and shortest reported duration of DM before the diagnosis of diabetic retinopathy (DR).

MAIN OUTCOME MEASURES

Prevalence of DR, cataract, high refractive error, and strabismus.

RESULTS

A total of 370 children (mean age, 11.2 years; range, 1-17.5 years) had 693 examinations, with a mean DM duration of 5.2 years (range, 0.1-16.2 years) and a mean hemoglobin A1c (HbA1c) of 8.6 (range, 5-≥14). No children had DR. A total of 12 children had cataract; 5 required extraction but were identified by decreased vision, not diabetic screening. A total of 19 children had strabismus; only 1 was microvascular paralytic strabismus. A total of 41 children had high refractive error. There were no associations between these conditions and duration or control of DM. In the literature, the youngest age at diagnosis of severe DR was 15 years, and the shortest duration of disease was 5 years.

CONCLUSIONS

Diabetic retinopathy is rare in children regardless of duration and control of DM. On the basis of our study and literature review, screening examinations for type 1 diabetes could begin at age 15 years or at 5 years after the diagnosis of DM, whichever occurs later, unless the child is judged by the endocrinologist as being at unusually high risk. Other ocular complications are identifiable through existing amblyopia screening methods.

Extending the diabetic retinopathy screening interval beyond 1 year: systematic review

To determine whether the recommended screening interval for diabetic retinopathy (DR) in the UK can safely be extended beyond 1 year. Systematic review of clinical and cost-effectiveness studies. Nine databases were searched with no date restrictions. Randomised controlled trials (RCTs), cohort studies, prognostic or economic modelling studies which described the incidence and progression of DR in populations with type 1 diabetes mellitus or type 2 diabetes mellitus of either sex and of any age reporting incidence and progression of DR in relation to screening interval (vs annual screening interval) and/or prognostic factors were included. Narrative synthesis was undertaken. 14 013 papers were identified, of which 11 observational studies, 5 risk stratification modelling studies and 9 economic studies were included. Data were available for 262 541 patients of whom at least 228 649 (87%) had type 2 diabetes. There were no RCTs. Studies concluded that there is little difference between clinical outcomes from screening 1 yearly or 2 yearly in low-risk patients. However there was high loss to follow-up (13–31%), heterogeneity in definitions of low risk and variation in screening and grading protocols for prior retinopathy results. Observational and economic modelling studies in low-risk patients show little difference in clinical outcomes between 1-year and 2-year screening intervals. The lack of experimental research designs and heterogeneity in definition of low risk considerably limits the reliability and validity of this conclusion. Cost-effectiveness findings were mixed. There is insufficient evidence to recommend a move to extend the screening interval beyond 1 year.

Current trends in the monitoring and treatment of diabetic retinopathy in young adults

The diagnosis and treatment of diabetic retinopathy (DR) in young adults have significantly improved in recent years. Research methods have widened significantly, for example, by introducing spectral optical tomography of the eye. Invasive diagnostics, for example, fluorescein angiography, are done less frequently. The early introduction of an insulin pump to improve the administration of insulin is likely to delay the development of diabetic retinopathy, which is particularly important for young patients with type 1 diabetes mellitus (T1DM). The first years of diabetes occurring during childhood and youth are the most appropriate to introduce proper therapeutic intervention before any irreversible changes in the eyes appear. The treatment of DR includes increased metabolic control, laserotherapy, pharmacological treatment (antiangiogenic and anti-inflammatory treatment, enzymatic vitreolysis, and intravitreal injections), and surgery. This paper summarizes the up-to-date developments in the diagnostics and treatment of DR. In the literature search, authors used online databases, PubMed, and clinitrials.gov and browsed through individual ophthalmology journals, books, and leading pharmaceutical company websites.

Screening intervals for diabetic retinopathy and incidence of visual loss: a systematic review

Screening for diabetic retinopathy can help to prevent this complication, but evidence regarding frequency of screening is uncertain. This paper systematically reviews the published literature on the relationship between screening intervals for diabetic retinopathy and the incidence of visual loss. The PubMed and EMBASE databases were searched until December 2012. Twenty five studies fulfilled the inclusion criteria, as these assessed the incidence/prevalence of sight-threatening diabetic retinopathy in relation to screening frequency. The included studies comprised 15 evaluations of real-world screening programmes, three studies modelling the natural history of diabetic retinopathy and seven cost-effectiveness studies. In evaluations of diabetic retinopathy screening programmes, the appropriate screening interval ranged from one to four years, in people with no retinopathy at baseline. Despite study heterogeneity, the overall tendency observed in these programmes was that 2-year screening intervals among people with no diabetic retinopathy at diagnosis were not associated with high incidence of sight-threatening diabetic retinopathy. The modelling studies (non-economic and economic) assessed a range of screening intervals (1-5 years). The aggregated evidence from both the natural history and cost-effectiveness models favors a screening interval >1 year, but ≤2 years. Such an interval would be appropriate, safe and cost-effective for people with no diabetic retinopathy at diagnosis, while screening intervals ≤1 year would be preferable for people with pre-existing diabetic retinopathy. A 2-year screening interval for people with no sight threatening diabetic retinopathy at diagnosis may be safely adopted. For patients with pre-existing diabetic retinopathy, a shorter interval ≤1 year is warranted.

Clinical characteristics influence screening intervals for diabetic retinopathy

AIMS/HYPOTHESIS

Most guidelines recommend annual screening for diabetic retinopathy (DR) but limited resources and the slow progression of DR suggest that longer recall intervals should be considered if patients have no detectable lesions. This study aimed to identify the cumulative incidence and time of development of referable DR in patients with no DR at baseline, classified by clinical characteristics.

METHODS

Analysis was performed of data collected prospectively over 20 years in a screening clinic based in a teaching hospital according to a consensus protocol. The cumulative incidence, time of development and relative risk of developing referable retinopathy over 6 years following a negative screening for DR were calculated in 4,320 patients, stratified according to age at onset of diabetes (<30 or ≥ 30 years), being on insulin treatment at the time of screening and known duration of diabetes (<10 or ≥ 10 years).

RESULTS

The 6 year cumulative incidence of referable retinopathy was 10.5% (95% CI 9.4, 11.8). Retinopathy progressed within 3 years to referable severity in 6.9% (95% CI 4.3, 11.0) of patients with age at onset ≥ 30 years, who were on insulin treatment and had a known disease duration of 10 years or longer. The other patients, especially those with age at onset <30 years, on insulin and <10 years duration, progressed more slowly.

CONCLUSIONS/INTERPRETATION

Screening can be repeated safely at 2 year intervals in any patient without retinopathy. Longer intervals may be practicable, provided all efforts are made to ensure adherence to standards in procedures and to trace and recall non-attenders.

Prevalence of diabetic retinopathy in various ethnic groups: a worldwide perspective

The alarming rise in diabetes prevalence is a global public health and economic problem. Diabetic retinopathy is the most common complication of diabetes and the leading cause of blindness among working-age populations in the Western world. Screening and prompt treatment of diabetic retinopathy are not top priorities in many regions of the world, because the impacts of other causes of preventable blindness remain an issue. Ethnicity is a complex, independent risk factor for diabetic retinopathy. Observations from white populations cannot be extrapolated fully to other ethnic groups. The prevalence of diabetic retinopathy, sight-threatening diabetic retinopathy, and clinically significant macular edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the white population. Although all ethnic groups are susceptible to the established risk factors of diabetic retinopathy-such as length of exposure and severity of hyperglycemia, hypertension, and hyperlipidemia-ethnic-specific risk factors also may influence these rates. Such risk factors may include differential susceptibility to conventional risk factors, insulin resistance, differences in anthropometric measurements, truncal obesity, urbanization, variations in access to healthcare systems, genetic susceptibility, and epigenetics. The rates of nonproliferative diabetic retinopathy appear to be declining in the United States, supporting the observation that better medical management of diabetes and prompt treatment of sight-threatening diabetic retinopathy substantially improve the long-term diabetic retinopathy incidence; studies from other parts of the world are limited and do not mirror this finding, however. We examine the ethnicity and region-based prevalence of diabetic retinopathy around the world and highlight the need to reinforce ethnicity-based screening and treatment thresholds in diabetic retinopathy.

Retinopathy screening in patients with type 1 diabetes diagnosed in young age using a non-mydriatic digital stereoscopic retinal imaging

BACKGROUND

Diabetic retinopathy seriously impairs patients' quality of life, since it represents the first cause of blindness in industrialized countries.

AIM

To estimate prevalence of retinopathy in young Type 1 diabetes patients using a non-mydriatic digital stereoscopic retinal imaging (NMDSRI), and to evaluate the impact of socio-demographic, clinical, and metabolic variables.

SUBJECTS AND METHODS

In 247 young patients glycated hemoglobin (HbA1c), gender, age, pubertal stage, presence of diabetic ketoacidosis (DKA), HLA-DQ heterodimers of susceptibility for Type 1 diabetes, and β-cell autoimmunity at clinical onset were considered. At retinopathy screening, we evaluated age, disease duration, pubertal stage, body mass index (BMI-SDS), insulin requirement, HbA1c levels, other autoimmune diseases, diabetes-related complications, serum concentrations of cholesterol and triglycerides, systolic and diastolic blood pressure.

RESULTS

Retinopathy was found in 26/247 patients: 25 showed background retinopathy, and 1 had a sight-threatening retinopathy. A significant relationship between retinopathy and female gender (p=0.01), duration of disease ≥15 yr (p<0.0001), serum triglycerides levels >65 mg/dl (p=0.012) and mean HbA1c ≥7.5% or >9% (p=0.0014) were found at the multivariate logistic analysis.

CONCLUSIONS

Metabolic control is the most important modifiable factor and promotion of continuous educational process to reach a good metabolic control is a cornerstone to prevent microangiopathic complications. Symptoms appear when the complication is already established; a screening program with an early diagnosis is mandatory to prevent an irreversible damage.

Microvascular disease in children and adolescents with type 1 diabetes and obesity

The incidence of type 1 diabetes (T1D) is increasing worldwide and is associated with a significant burden, mainly related to the development of vascular complications. Over the last decades, concomitant with the epidemic of childhood obesity, there has been an increasing number of cases of type 2 diabetes (T2D) among children and adolescents. Microvascular complications of diabetes, which include nephropathy, retinopathy and neuropathy, are characterized by damage to the microvasculature of the kidney, retina and neurons. Although clinically evident microvascular complications are rarely seen among children and adolescents with diabetes, there is clear evidence that their pathogenesis and early signs develop during childhood and accelerate during puberty. Diabetic vascular complications are often asymptomatic during their early stages, and once symptoms develop, there is little to be done to cure them. Therefore, screening needs to be started early during adolescence and, in the case of T2D, already at diagnosis. Identification of risk factors and subclinical signs of complications is essential for the early implementation of preventive and therapeutic strategies, which could change the course of vascular complications and improve the prognosis of children, adolescents and young adults with diabetes.

[Microvascular and macrovascular complications in children and adolescents with type 1 diabetes mellitus]

Diabetes-related microvascular and macrovascular complications, as retinopathy, nephropathy and neuropathy are life-threatening complications in children and adolescents with type 1 diabetes mellitus (T1DM). Risk factors for the development of complications are longer duration of diabetes, older age and puberty. Further risk factors include smoking, hypertension, higher body mass index and dyslipoproteinaemia. Therefore prevention and screening for complications is an important part in the care of children and adolescents with T1DM. Target levels to reduce the risk of microvascular and macrovascular complications in children and adolescents with T1DM are the following: HbA1c<7.5%, lipids in normal range, blood pressure<90th percentile by age, sex and height, BMI<95th percentile, no smoking and physical activity. Screening for retinopathy and microalbuminuria should start from 11 years with two years diabetes duration and from 9 years with 5 years duration and after 2 years diabetes duration in an adolescent. Thereafter screening should be performed annually. Blood pressure should be measured at least annually. Screening for fasting blood lipids should be performed soon after diagnosis in all children with T1DM aged over 12 years. If normal results are obtained, this should be repeated every 5 years.

Prevention and treatment of microvascular disease in childhood type 1 diabetes

INTRODUCTION

The incidence of type 1 diabetes (T1D) is increasing worldwide, particularly in children, and is associated with a significant burden, mainly related to the development of vascular complications. The prevention and treatment of microvascular complications, which include nephropathy, retinopathy and neuropathy, are of paramount importance to decrease the associated mortality and morbidity.

SOURCES OF DATA

A literature search was performed on Medline and articles on microvascular complications, with particular emphasis on the increasing incidence of childhood T1D and its implications on prevention and treatment of complications, were selected.

AREAS OF AGREEMENT

The incidence of childhood T1D is increasing. Early identification of subjects at risk for long-term complications and early implementation of preventive and therapeutic strategies are fundamental in order to reduce the burden associated with microvascular complications of diabetes. Improving glycaemic control is the principle way of preventing and treating T1D complications.

AREAS OF CONTROVERSY

In adults with T1D and microvascular complications, treatment with anti-hypertensive drugs and statins is increasingly common, whereas there are no definitive indications for treatment with these drugs in children and adolescents with early signs of complications.

GROWING POINTS

There is growing interest in the development of new preventive and therapeutic strategies targeting specific pathways implicated in the pathogenesis of microvascular complications.

AREAS TIMELY FOR DEVELOPING RESEARCH

Investigations to clarify genetic and environmental factors implicated in the pathogenesis of microvascular complications could lead to the identification of biochemical markers with high predictive values, to be used as a guide for screening and intervention programmes.

Retinal vascular fractal dimension and risk of early diabetic retinopathy: A prospective study of children and adolescents with type 1 diabetes

OBJECTIVE

To examine the prospective association of retinal vascular fractal dimension with diabetic retinopathy risk in young people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a hospital-based prospective study of 590 patients aged 12-20 years with type 1 diabetes free of retinopathy at baseline. All patients had seven-field retinal photographs taken of both eyes. Incident retinopathy was ascertained from retinal photographs taken at follow-up visits. Fractal dimension was measured from baseline photographs using a computer-based program following a standardized protocol.

RESULTS

Over a mean +/- SD follow-up period of 2.9 +/- 2.0 years, 262 participants developed mild nonproliferative diabetic retinopathy (15.0 per 100 person-years). After adjusting for age, sex, diabetes duration, A1C, and other risk factors, we found no association between retinal vascular fractal dimension and incident retinopathy.

CONCLUSIONS

Retinal vascular fractal dimension was not associated with incident early diabetic retinopathy in this sample of children and adolescents with type 1 diabetes.

Quantitative assessment of early diabetic retinopathy using fractal analysis

OBJECTIVE

Fractal analysis can quantify the geometric complexity of the retinal vascular branching pattern and may therefore offer a new method to quantify early diabetic microvascular damage. In this study, we examined the relationship between retinal fractal dimension and retinopathy in young individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study of 729 patients with type 1 diabetes (aged 12-20 years) who had seven-field stereoscopic retinal photographs taken of both eyes. From these photographs, retinopathy was graded according to the modified Airlie House classification, and fractal dimension was quantified using a computer-based program following a standardized protocol.

RESULTS

In this study, 137 patients (18.8%) had diabetic retinopathy signs; of these, 105 had mild retinopathy. Median (interquartile range) retinal fractal dimension was 1.46214 (1.45023-1.47217). After adjustment for age, sex, diabetes duration, A1C, blood pressure, and total cholesterol, increasing retinal vascular fractal dimension was significantly associated with increasing odds of retinopathy (odds ratio 3.92 [95% CI 2.02-7.61] for fourth versus first quartile of fractal dimension). In multivariate analysis, each 0.01 increase in retinal vascular fractal dimension was associated with a nearly 40% increased odds of retinopathy (1.37 [1.21-1.56]). This association remained after additional adjustment for retinal vascular caliber.

CONCLUSIONS

Greater retinal fractal dimension, representing increased geometric complexity of the retinal vasculature, is independently associated with early diabetic retinopathy signs in type 1 diabetes. Fractal analysis of fundus photographs may allow quantitative measurement of early diabetic microvascular damage.

Methylenetetrahydrofolate reductase and methionine synthase reductase gene polymorphisms and protection from microvascular complications in adolescents with type 1 diabetes

Folate status has been associated with endothelial dysfunction in adolescents with type 1 diabetes, and elevated total plasma homoocyst(e)ine (tHcy) is a risk for vascular disease in the non-diabetic population. Polymorphisms in genes involved in folate and homocysteine metabolism are implicated in vascular disease. We aimed to determine whether polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes are risk factors for early microvascular disease in a large group of adolescents with type 1 diabetes. Four hundred and eighty adolescents were screened annually for retinopathy and microalbuminuria for a median of 4 yr. Molecular analysis for the polymorphisms 677C-->T, 1298A-->C in MTHFR, and 66A-->G in MTRR was performed. The MTRR 66GG genotype reduced the risk for elevated albumin excretion rate (AER) (OR 0.47, CI 0.25, 0.88, p = 0.018) and showed a trend to reduced risk for microalbuminuria (OR 0.27, CI 0.06-1.21, p = 0.09). Survival without elevated AER was increased with the MTRR 66GG genotype (12.4 vs. 9.7 yr, p = 0.04) and with the MTHFR 1298CC genotype (15.2 vs. 10.2 yr, p = 0.007). Conversely, survival without retinopathy was reduced with the MTHFR 677TT and MTRR 66GG combined genotype (6.2 vs. 10.2 yr, p = 0.015). The MTRR 66GG and MTHFR 1298 CC genotypes may confer protection against early nephropathy, possibly because they are associated with lower tHcy. The MTHFR 677 TT was only related to earlier onset retinopathy in combination with MTRR 66GG.

Identifying children at particular risk of long-term diabetes complications

Formerly a 'taboo' subject, long-term complications are now being increasingly discussed with the family by the health-care team. Identifying potential predictors and establishing early intervention can change the course of these complications in the young patient with diabetes. Although the most recognized risk factor is glycaemic exposure, the development of diabetes complications is likely to result from an interaction between genetic and environmental factors. Other major environmental risk factors are hypertension, smoking, higher body mass index and lipid disorders. This article will concentrate on specific paediatric aspects, including the impact of puberty; endothelial dysfunction and genetic susceptibility. Endothelial function assessed by flow-mediated dilatation is a non-invasive method that has been suitable for use in children and adolescents. In type 1 diabetes mellitus children, endothelium dysfunction has been documented among patients with short diabetes duration and has been correlated to folate status, triglyceride and low-density lipoprotein cholesterol levels. Studies in the paediatric population have also revealed an association of diabetes complications with genetic variants in the renin-angiotensin system, polyol pathway, lipid oxidation and folate metabolism. Currently, achieving the best glycaemic control remains the gold standard for prevention of long-term diabetes complications in the clinical context. However, recent identification of genetic markers and development of research tools that predict long-term complications might have a potential role as instruments in assessing the effectiveness of intervention in the early course of the disease.

Prevalence of diabetic retinopathy in children and adolescents with type-1 diabetes attending summer camps in France

OBJECTIVE

To evaluate, using fundus photography, the prevalence of diabetic retinopathy (DR) in young diabetic subjects attending summer camps run by the Aide aux Jeunes Diabétiques Association (Aid to Young Diabetics).

RESEARCH DESIGN AND METHODS

Five hundred and four children and adolescents (250 boys and 254 girls), with type 1 diabetes mellitus, aged 10-18 years (mean:13+/-2), were screened for DR using non mydriatic photography, during their stay in a holiday camp. Demographic and clinical data recorded on subjects' arrival in the camp included date of birth, height, weight, treatment, blood pressure, and duration of diabetes. HbA(1c) was determined with a DCA 2000 kit.

RESULTS

Mean diabetes duration was 4.8+/-3.4 years and mean HbA(1c) was 8.5+/-1.3%. Mild non proliferative DR was diagnosed in 23 children (4.6%). Compared to subjects without DR, those with DR were significantly older (P<10(-3)), had a longer duration of diabetes (P=0.001), higher systolic blood pressure (P=0.04), and had higher (but not significantly so) HbA(1c) (P=0.15). After adjustment for age, only longer duration remained significantly associated with DR (P=0.01).

CONCLUSION

The prevalence of DR in these young patients was low compared to that reported in previous studies. The decrease may be due to modern diabetes care with multiple insulin injections. However, early detection of DR in adolescents, especially in their late teens, remains important, because it allows the identification of patients at high risk of progression towards severe stages of DR.

Contemporary Australian outcomes in childhood and adolescent type 1 diabetes: 10 years post the Diabetes Control and Complications Trial

The reporting of the results of the Diabetes Control and Complications Trial in 1993 has led to a major reappraisal of management practices and outcomes in type 1 diabetes in children and adolescents. A considerable body of outcome data has been generated from Australia in this post-Diabetes Control and Complications Trial era relating to incidence, metabolic control, growth, hypoglycaemia, microvascular and macrovascular complications, cognition, behaviour and quality of life. These data are important in planning future management strategies and resource allocation and as a basis for future research.

Prevalence of diabetes complications in adolescents with type 2 compared with type 1 diabetes

OBJECTIVE

To compare the prevalence of diabetes complications and their risk factors in youth with type 1 versus type 2 diabetes.

RESEARCH DESIGN AND METHODS

We performed a comparative clinic-based study of 1,433 patients with type 1 diabetes and 68 patients with type 2 diabetes aged <18 years from New South Wales, Australia. Retinopathy was assessed by seven-field stereoscopic retinal photography; albumin excretion rate from three consecutive, timed, overnight urine collections; peripheral neuropathy by thermal and vibration threshold; and autonomic neuropathy by pupillometry. HbA(1c) (A1C) and lipids were measured in all patients and C-peptide in patients with type 2 diabetes.

RESULTS

In patients with type 1 versus type 2 diabetes, median (interquartile range) age was 15.7 years (13.9-17.0) and 15.3 years (13.6-16.4), respectively (P = 0.2), whereas median diabetes duration was 6.8 years (4.7-9.6) and 1.3 years (0.6-3.1), respectively (P < 0.0001). Retinopathy was significantly more common in patients with type 1 diabetes (20 vs. 4%, P = 0.04), while microalbuminuria and hypertension were significantly less common (6 and 16% in type 1 diabetes vs. 28 and 36% in type 2 diabetes). Rates of peripheral and autonomic neuropathy were similar (27 and 61% in type 1 diabetes vs. 21 and 57% in type 2 diabetes). In multivariate analyses, microalbuminuria was significantly associated with older age (odds ratio 1.3 [95% CI 1.2-1.5], P < 0.001) and systolic hypertension (3.63 [2.0-6.3], P < 0.001) in type 1 diabetes, while only higher A1C (1.7 [1.3-2.9], P = 0.002) was significant in patients with type 2 diabetes.

CONCLUSIONS

Youth with type 2 diabetes have significantly higher rates of microalbuminuria and hypertension than their peers with type 1 diabetes, despite shorter diabetes duration and lower A1C. The results of this study support recommendations for early complications screening and aggressive targeting of glycemic control in patients with type 2 diabetes.

Complications of diabetes mellitus in childhood

Complications of diabetes include retinopathy, nephropathy, neuropathy, macrovascular disease, and associated autoimmune diseases. Clinical manifestations of complications uncommonly present in childhood and adolescence. Screening during the early years can identify subclinical disease and it offers an opportunity for early intervention. The Diabetes and Complications Control Trial has provided evidence for the long-term benefits of good glycemic control in preventing and delaying the onset of microvascular complications. Complications begin to manifest during adolescence, during which time all efforts should be made to educate and support young persons in achieving optimal diabetes control.