Prevalence of diabetic retinopathy in children and adolescents with IDDM. A population-based multicentre study

Acute panendothelial retinal leakage in a patient with diabetes mellitus type 1 with a poor metabolic control

Ophthalmological diabetic complications are one of the main causes of blindness worldwide, so careful diagnostic and management is important. The screening plans implemented in our population made possible an early diagnosis and treatment, trying to reduce the consequences. Diabetic retinopathy is widely known, however we present the case of a rare retinal condition, acute panedothelial retinal leakage. It typically affects patients with type 1 DM and poor glycemic control. Its diagnosis is important since a strict metabolic control is sufficient for its resolution, avoiding aggressive therapies.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Global and Regional Prevalence of Diabetic Retinopathy; A Comprehensive Systematic Review and Meta-analysis

PURPOSE

We conducted a systematic search to estimate DR prevalence in different age and gender groups, and to evaluate the determinants of heterogeneity in its prevalence.

METHODS

A systematic and comprehensive search from inception to August 10, 2020, was done in international databases, including Scopus, PubMed, Web of Science, Embase, and other data sources without any restriction to find cross-sectional studies related to the prevalence of DR.

RESULTS

Of 6399 studies, 90 articles with a sample size of 563460 individuals and 204189 diabetic patients were analyzed. The estimated pooled prevalence of DR in the diabetic population in general; in female and in male was 28.41% (95% CI: 25.98 to 30.84); 25.93% (95% CI: 23.54 to 28.31) and 28.95% (95% CI: 26.57 to 31.32); respectively and the prevalence of DR showed no inter-gender difference. The heterogeneity of the pooled prevalence according to I² was 99% (p < .001). According to the meta-regression results, the variables of WHO region (Coefficient of AMRO vs SEARO: 15.56; p: 0.002), age (Coefficient of above 60 years vs below 40 year: 18.67; p: 0.001), type of DR (Coefficient: 19.01; p < .001), and publication year (Coefficient: -0.60; p: 0.001) had a significant correlation with heterogeneity.

CONCLUSION

One third of diabetic patients suffered from DR, mostly NPDR. DR increased markedly after the age of 60 years, which could be due to the longer duration of diabetes. Age, WHO region, type of DR, and publication year affected the heterogeneity in the prevalence of DR.

Evaluation of Macular and Retinal Nerve Fiber Layer Thickness in Children with Type 1 Diabetes Mellitus without Retinopathy

PURPOSE

There are limited data from Asian countries regarding retinal thickness in children with type 1 diabetes mellitus (T1DM). This study aimed to compare the macular and retinal nerve fiber layer (RNFL) parameters between diabetic children without retinopathy and non-diabetic healthy children. We also evaluated the factors associated with RNFL thickness in children with T1DM.

METHODS

A comparative cross-sectional study was conducted among children with T1DM and healthy children aged 7 to 17 years old in Hospital Universiti Sains Malaysia from 2017 to 2019. Children with retinal disease or glaucoma were excluded. Macular and RNFL thicknesses were measured using spectral-domain optical coherence tomography. Demographic information, duration of diabetes, blood pressure, body mass index, visual acuity, and retinal examination findings were documented. Glycosylated hemoglobin levels, renal function, and blood lipid levels were also collected.

RESULTS

Forty-one children with T1DM and 80 age- and sex-matched children were enrolled. Both sexes were affected. Mean duration of diabetes mellitus was 3.66 years. The mean glycated hemoglobin levels in the T1DM group was 9.99%. The mean macular and RNFL thicknesses in children with T1DM were 277.56 (15.82) µm and 98.85 (12.05) µm, respectively. Children with T1DM had a significantly thinner average macula, superior outer macula, nasal outer macula, mean RNFL, and inferior RNFL thickness compared to controls (p < 0.05). There was a significant association between nephropathy and the mean RNFL thickness.

CONCLUSIONS

Children with T1DM had significantly decreased mean macular and RNFL thicknesses. Nephropathy is associated with an increased RNFL thickness.

Acute panendothelial retinal leakage in a patient with diabetes mellitus type 1 with a poor metabolic control

Ophthalmological diabetic complications are one of the main causes of blindness worldwide, so careful diagnostic and management is important. The screening plans implemented in our population made possible an early diagnosis and treatment, trying to reduce the consequences. Diabetic retinopathy is widely known, however we present the case of a rare retinal condition, acute panedothelial retinal leakage. It typically affects patients with diabetes mellitus (DM) type 1 and poor glycemic control. Its diagnosis is important since a strict metabolic control is sufficient for its resolution, avoiding aggressive therapies.

Prevalence of diabetic retinopathy in children and adolescents at an urban tertiary eye care center

BACKGROUND

Diabetic retinopathy (DR) is a serious complication that can progress to sight-threatening disease. The prevalence of DR in youth with diabetes has been reported to be 3.8% to 20%.

OBJECTIVE

We aimed to evaluate the prevalence of DR among youth with diabetes at a large ophthalmologic referral center. Secondary goals were to determine the risk factors for DR and severity of disease.

METHODS

Retrospective chart review of 343 patients with diabetes, <21 years of age, seen at a tertiary referral eye care center from 2013 to 2018.

RESULTS

The study included 343 patients, of which 293 had type 1 diabetes (T1D) and 50 had type 2 diabetes (T2D). Thirteen of 343 patients had DR, with an overall incidence of 3.8% (3.4% in T1D and 6% T2D). DR severity included nine with mild non-proliferative, three moderate non-proliferative, and one with proliferative DR. Patients with hemoglobin A1c (HbA1c) > 8% had a higher risk of DR (P = .049). In this cohort, none of the patients with an HbA1c <8% had DR. In the multivariate analysis, a higher systolic blood pressure was marginally associated with risk for DR (P = .07).

CONCLUSIONS

We found lower prevalence of DR in youth with diabetes than previously reported. The incidence of DR was higher among patients with T2D and occurred with a shorter duration of disease, as compared with T1D. While the incidence of DR in youth with T1D is low, with the increasing incidence of T2D in adolescents and early risk for DR, early screening must be emphasized.

Vascular Complication in Adolescents With Diabetes Mellitus

Diabetes mellitus is becoming more prevalent and even with new advancements which improve glycaemic control, complications of diabetes are common. Vascular complications of diabetes include the microvascular complications: retinopathy, nephropathy, and peripheral and autonomic neuropathy. Macrovascular complications are also common in patients with diabetes and arguably more concerning as they confer a high mortality risk yet are sometimes under-treated. Risk factors for diabetes complications start to occur in childhood and adolescents and some youths may be diagnosed with complications before transition to adult care. This article discusses the prevalence, risk factors, screening, and treatment recommendations for vascular complications in children and adolescents with diabetes.

Prevalence, incidence and future projection of diabetic eye disease in Europe: a systematic review and meta-analysis

To examine the prevalence and incidence of diabetic eye disease (DED) among individuals with diabetes in Europe, a systematic review to identify all published European prevalence and incidence studies of DED in individuals with diabetes managed in primary health care was performed according to the MOOSE and PRISMA guidelines. The databases Medline, Embase and Web of Science were searched to 2 September 2017. Meta-analyses and meta-regressions were performed. The pooled prevalence estimates were applied to diabetes prevalence rates provided by the International Diabetes Foundation atlas and Eurostat population data, and extrapolated to the year 2050. Data of 35 prevalence and four incidence studies were meta-analyzed. Any diabetic retinopathy (DR) and diabetic macular edema (DME) were prevalent in 25.7% (95% CI 22.8-28.8%) and 3.7% (95% CI 2.2-6.2%), respectively. In meta-regression, the prevalence of DR in persons with type 1 diabetes was significantly higher compared to persons with type 2 diabetes (54.4% vs. 25.0%). The pooled mean annual incidence of any DR and DME in in persons with type 2 diabetes was 4.6% (95% CI 2.3-8.8%) and 0.4% (95% CI 0.5-1.4%), respectively. We estimated that persons with diabetes affected by any DED in Europe will increase from 6.4 million today to 8.6 million in 2050, of whom 30% require close monitoring and/or treatment. DED is estimated to be present in more than a quarter of persons with type 2 diabetes and half of persons with type 1 diabetes underlining the importance of regular monitoring. Future health services need to be planned accordingly.

Analysis of Retinal Perfusion in Children, Adolescents, and Young Adults with Type 1 Diabetes Using Optical Coherence Tomography Angiography

We performed a cross-sectional study to analyze the retinal vasculature in children, adolescent, and young adults with type 1 diabetes using optical coherence tomography angiography (OCTA). Patients underwent funduscopic examination for diabetic retinopathy (DR) screening during an annual visit for the screening of diabetes-related complications which included the evaluation of glycated hemoglobin (HbA1c), microalbuminuria, lipid profile, arterial pressure, and neurological assessment. In addition, OCTA of the retinal vasculature was performed. Quantitative analysis of the OCTA images evaluated the vessel density at the superficial (SCP) and deep (DCP) capillary plexus of the retina. Structural vascular alterations were evaluated qualitatively. Results were compared to those obtained in a group of healthy age-, sex-, and pubertal stage-matched controls. The effect of age, disease duration, age at the disease onset, mean HbA1c since the onset, and lipid profile on vascular density was tested. Fifty-three patients (median age 15.5, IQR 12.4-19.4 years; 57% females) with type 1 diabetes and 48 controls were enrolled. The median (IQR) HbA1c was 7.6% (60 mmol/mol) (6.9-8.1%, 52-65 mmol/mol), and the median (IQR) duration of disease was 6.0 (3.3-10.3) years. Mean vessel density measured with OCTA was lower in patients compared to controls with the temporal sector showing the highest difference both in the SCP (0.55 vs. 0.57, p < 0.001) and the DCP (0.63 vs. 0.65, p < 0.001). None of the predictors was associated with the superficial and deep vascular densities. Only 2 patients had clinically detectable DR. Microvascular structural changes were found on OCTA in both of these patients and in one without funduscopic alterations. In conclusion, patients with type 1 diabetes without clinically detectable DR had decreased capillary density compared to controls on OCTA images. These findings may provide useful information for the screening and the management of patients with type 1 diabetes. Further studies are needed to confirm our results and their clinical relevance.

Management of diabetes complications in youth

Type 1 and type 2 diabetes are increasing in prevalence and diabetes complications are common. Diabetes complications are rarely studied in youth, despite the potential onset in childhood. Microvascular complications of diabetes include retinopathy, diabetic kidney disease or nephropathy, and neuropathy that may be somatic or autonomic. Macrovascular disease is the leading cause of death in patients with type 1 diabetes. Strict glycaemic control will reduce microvascular and macrovascular complications; however, they may still manifest in youth. This article discusses the diagnosis and treatment of complications that arise from type 1 and type 2 diabetes mellitus in youth. Screening for complications is paramount as early intervention improves outcome. Screening should commence from 11 years of age depending on the duration of type 1 diabetes or at diagnosis for patients with type 2 diabetes. Diabetic retinopathy may require invasive treatment such as laser therapy or intravitreal antivascular endothelial growth factor therapy to prevent future blindness. Hypertension and albuminuria may herald diabetic nephropathy and require management with angiotensin converting enzyme (ACE) inhibition. In addition to hypertension, dyslipidaemia must be treated to reduce macrovascular complications. Interventional trials aimed at examining the treatment of diabetes complications in youth are few. Statins, ACE inhibitors and metformin have been successfully trialled in adolescents with type 1 diabetes with positive effects on lipid profile, microalbuminuria and measures of vascular health. Although relatively rare, complications do occur in youth and further research into effective treatment for diabetes complications, particularly therapeutics in children in addition to prevention strategies is required.

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.

Risk of diabetic retinopathy at first screen in children at 12 and 13 years of age

AIMS

To investigate the relationships between age at diagnosis of diabetes, age at diabetic eye screening and severity of diabetic retinopathy at first and subsequent screenings in children aged 12 or 13 years.

METHODS

Data were extracted from four English screening programmes and from the Scottish, Welsh and Northern Irish programmes on all children with diabetes invited for their first and subsequent screening episodes from the age of 12 years. Retinopathy levels at first and subsequent screens, time from diagnosis of diabetes to first screening and age at diagnosis in years were calculated.

RESULTS

Data were available for 2125 children with diabetes screened for the first time at age 12 or 13 years. In those diagnosed with diabetes at 2 years of age or less, the proportion with retinopathy in one or both eyes was 20% and 11%, respectively, decreasing to 8% and 2% in those diagnosed between 2 and 12 years (P < 0.0001). Only three children (aged 8, 10 and 11 years at diagnosis of diabetes) had images graded with referable retinopathy and, of these, two had non-referable diabetic retinopathy at all subsequent screenings. Of 1703 children with subsequent images, 25 were graded with referable diabetic retinopathy over a mean follow-up of 3.1 years, an incidence rate of 4.7 (95% confidence interval, 3.1-7.0) per 1000 per year.

CONCLUSIONS

In this large cohort of children, the low prevalence and incidence rates of referable diabetic retinopathy suggest that screening earlier than age 12 is not necessary.

Fundus Photography as a Screening Method for Diabetic Retinopathy in Children With Type 1 Diabetes: Outcome of the Initial Photography

PURPOSE

To determine the success rate of the initial fundus photography session in producing gradable images for screening diabetic retinopathy in children <18 years of age with type 1 diabetes (T1D), and to analyze outcome-associated factors.

DESIGN

Retrospective observational cohort study.

METHODS

Mydriatic red-free monochromatic 60-degree digital fundus images centered on the macula and optic disc of 213 patients were graded. Photography success was classified as "complete" if both images of both eyes were gradable, "partial" if both images of 1 eye were gradable, "macula-centered image(s) only" if only the macula-centered image of one or both eyes was gradable, and "unsuccessful" if neither macula-centered image was gradable.

RESULTS

Complete success was reached in 97 (46%; 95% confidence interval [CI], 39-52) patients, at least partial success in 153 (72%; 95% CI, 65-78) patients, success of macula-centered image(s) only in 47 (22%; 95% CI, 17-28) patients, and in 13 (6%; 95%CI, 3-10) patients fundus photography was unsuccessful. Macula-centered images were more often gradable in both eyes than optic disc-centered images (P < .001). Success of photography did not differ between right and left eye. Sex, age at diagnosis of T1D, and the duration of diabetes, age, and glycemic control at the time of initial photography were unassociated with complete success. Partial success tended to decrease with increasing age category (P = .093), and the frequency of gradable macula-centered image(s) only increased with increasing age (P = .043).

CONCLUSIONS

Less than half of the children achieved complete success, but in only 6% initial fundus photography was unsuccessful, indicating its value in assessing retinopathy in the pediatric setting.

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.

Diagnosis of retinopathy in children younger than 12 years of age: implications for the diabetic eye screening guidelines in the UK

AimTo assess whether the current starting age of 12 is suitable for diabetic retinopathy (DR) screening and whether diabetes duration should be taken into account when deciding at what age to start screening patients.Materials and methodsA retrospective analysis of 143 patients aged 12 years or younger who attended diabetic eye screening for the first time in the Birmingham, Solihull and Black Country Diabetic Eye Screening Programme was performed.ResultsThe mean age of the patients was 10.7 (7-12) years with 73 out of 143 aged below 12 years and 70 were 12 years of age. 98% had type 1 diabetes and mean diabetes duration was 5 (1 month-11 years) years. For those younger than 12 years, 7/73 (9.6%) had background DR (BDR), of these mean diabetes duration was 7 years (6-8). The youngest patient to present with DR was aged 8 years. In those aged 12 years, 5/70 (7.1%) had BDR; of these mean diabetes duration was 8 years (6-11). No patient developed DR before 6 years duration in either group.ConclusionsThe results show that no patient younger than the age of 12 had sight-threatening DR (STDR), but BDR was identified. Based on the current mission statement of the Diabetic Eye Screening Programme to identify STDR, 12 years of age is confirmed as the right age to start screening, but if it is important to diabetic management to identify first development of DR, then screening should begin after 6 years of diabetes diagnosis.

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.

Interventions for Diabetic Retinopathy in Type 1 Diabetes: Systematic Review and Meta-Analysis

PURPOSE

To systematically review the effectiveness of systemic interventions for diabetic retinopathy (DR) in type 1 diabetes.

DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE and Cochrane Library were searched for studies published from January 1990 to December 2014. Randomized controlled trials and controlled cohort studies reporting incidence or progression of DR following systemic intervention were included. Two reviewers selected studies, extracted data, and assessed risk of bias. For each intervention, pooled outcomes were reported as relative risk (RR) estimates with 95% confidence intervals (CI).

RESULTS

Twenty-four studies involving 9302 patients met inclusion criteria. Incident DR was reduced by intensive vs conventional insulin therapy (RR 0.43; 95% CI 0.23-0.83), insulin pumps vs multiple daily injections (RR 0.45; 95% CI 0.24-0.83), and angiotensin receptor blockade vs placebo (RR 0.65; 95% CI 0.49-0.85). The benefit of insulin pumps over multiple daily infections was independent of HbA1c. DR progression was reduced by intensive vs conventional insulin therapy (RR 0.63; 95% CI 0.43-0.92), angiotensin-converting enzyme inhibition vs placebo (RR 0.60; 95% CI 0.41-0.86), and islet cell transplantation vs medical therapy (RR 0.25; 95% CI 0.08-0.71).

CONCLUSIONS

Intensive insulin therapy, and specifically insulin pump therapy vs multiple daily injections, prevents DR in both adults and adolescents with type 1 diabetes. Antihypertensive agents provide protection in normotensive, normoalbuminuric adults. In patients with type 1 diabetes of longer duration, islet cell transplantation may be more effective than medical therapy. There is insufficient evidence for antilipid therapy or other systemic interventions.

Long-term Outcomes in Youths with Diabetes Mellitus

In this article, the author reviews the long-term outcomes and their precursors of type 1 diabetes starting in youth. The author also contrasts the changing incidence of these long-term complications as we have moved from the pre-Diabetes Control and Complications Trial (DCCT) to the post-DCCT standard of care and reviews the emerging data related to complications in youths with type 2 diabetes. Finally, the author reviews the recent understanding related to the effects of diabetes on the brain and cognition.

Prevalence of retinopathy in patients with type 1 diabetes diagnosed before and after puberty

AIMS

There is conflicting evidence to support the concept that the years with diabetes preceding puberty may not contribute to the development of vascular complications. In this paper, duration-related prevalence of retinopathy was compared in patients who developed type 1 diabetes before and after pubertal age.

METHODS

Retrospective analysis of prospectively collected data of 1,483 patients was screened for retinopathy in 1991-2010, with diabetes onset at age ≤29, who were on insulin treatment and aged ≤60. Prepubertal age was defined as 0-12 in males and 0-11 in females.

RESULTS

A total of 647 patients had developed diabetes before and 836 after puberty. Cumulative prevalence of retinopathy was initially lower among those with prepubertal onset diabetes but rates became superimposable after 20-year duration. Patients with prepubertal onset diabetes had higher lifetime HbA1c and lower blood pressure than those who became diabetic after puberty.

CONCLUSIONS/INTERPRETATION

Retinopathy is infrequent during childhood and develops later than in patients with post-pubertal onset diabetes. After 20-year duration, however, retinopathy becomes just as prevalent suggesting that, in the long term, prepubertal years do contribute to the development of retinopathy. In this series, higher blood pressure may have played a role in the earlier appearance of retinopathy in patients with diabetes onset after puberty, whereas worse metabolic control may have contributed to the late "catch-up" effect in those with prepubertal onset disease.

Epidemiological issues in diabetic retinopathy

There is currently an epidemic of diabetes in the world, principally type 2 diabetes that is linked to changing lifestyle, obesity, and increasing age of the population. Latest estimates from the International Diabetes Federation (IDF) forecasts a rise from 366 million people worldwide to 552 million by 2030. Type 1 diabetes is more common in the Northern hemisphere with the highest rates in Finland and there is evidence of a rise in some central European countries, particularly in the younger children under 5 years of age. Modifiable risk factors for progression of diabetic retinopathy (DR) are blood glucose, blood pressure, serum lipids, and smoking. Nonmodifiable risk factors are duration, age, genetic predisposition, and ethnicity. Other risk factors are pregnancy, microaneurysm count in an eye, microaneurysm formation rate, and the presence of any DR in the second eye. DR, macular edema (ME), and proliferative DR (PDR) develop with increased duration of diabetes and the rates are dependent on the above risk factors. In one study of type 1 diabetes, the median individual risk for the development of early retinal changes was 9.1 years of diabetes duration. Another study reported the 25 year incidence of proliferative retinopathy among population-based cohort of type 1 patients with diabetes was 42.9%. In recent years, people with diabetes have lower rates of progression than historically to PDR and severe visual loss, which may reflect better control of glucose, blood pressure, and serum lipids, and earlier diagnosis.

Transient severe non-proliferative retinopathy in an adolescent with type 1 diabetes and chronic myeloid leukemia

The onset of diabetic retinopathy correlates with the long-term quality of glycemic control. A 17-yr-old adolescent with type 1 diabetes presented unexpectedly with acute non-proliferative retinopathy despite good glycemic control. Two months later chronic myeloid leukemia (CML) was diagnosed. Chemotherapy was initiated and within a few weeks the patient was in full remission concerning leukemia. Retinopathy completely resolved within 8 months. The patient was in good metabolic control throughout the course. To our knowledge, this is the first report of CML-triggered retinopathy in a well-controlled diabetic adolescent. In case of unexpected retinopathy in patients with type 1 diabetes, other potential causes of retinopathy should be considered.

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.

Role of blood pressure in development of early retinopathy in adolescents with type 1 diabetes: prospective cohort study

OBJECTIVE

To examine the relation between blood pressure and the development of early retinopathy in adolescents with childhood onset type 1 diabetes.

DESIGN

Prospective cohort study.

SETTING

Diabetes Complications Assessment Service at the Children's Hospital at Westmead, Sydney, Australia.

PARTICIPANTS

1869 patients with type 1 diabetes (54% female) screened for retinopathy with baseline median age 13.4 (interquartile range 12.0-15.2) years, duration 4.9 (3.1-7.0) years, and albumin excretion rate of 4.4 (3.1-6.8) microg/min plus a subgroup of 1093 patients retinopathy-free at baseline and followed for a median 4.1 (2.4-6.6) years.

MAIN OUTCOME MEASURES

Early background retinopathy; blood pressure.

RESULTS

Overall, retinopathy developed in 673 (36%) participants at any time point. In the retinopathy-free group, higher systolic blood pressure (odds ratio 1.01, 95% confidence interval 1.003 to 1.02) and diastolic blood pressure (1.01, 1.002 to 1.03) were predictors of retinopathy, after adjustment for albumin excretion rate (1.27, 1.13 to 1.42), haemoglobin A(1c) (1.08, 1.02 to 1.15), duration of diabetes (1.16, 1.13 to 1.19), age (1.13, 1.08 to 1.17), and height (0.98, 0.97 to 0.99). In a subgroup of 1025 patients with albumin excretion rate below 7.5 microg/min, the cumulative risk of retinopathy at 10 years' duration of diabetes was higher for those with systolic blood pressure on or above the 90th centile compared with those below the 90th centile (58% v 35%, P=0.03). The risk was also higher for patients with diastolic blood pressure on or above the 90th centile compared with those below the 90th centile (57% v 35%, P=0.005).

CONCLUSIONS

Both systolic and diastolic blood pressure are predictors of retinopathy and increase the probability of early retinopathy independently of incipient nephropathy in young patients with type 1 diabetes.

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.

Deterioration of visual acuity associated with growth hormone therapy in a child with extreme short stature and high hypermetropia

BACKGROUND

Growth hormone (GH) has long been implicated in the pathogenesis of diabetic retinopathy, although its precise role remains ill-defined. In 1998, an association between exogenous human GH and retinal pathology in non-diabetic subjects was described.

CASE REPORT

A female child with extreme short stature of unknown aetiology (height -7.38 SD at 11.3 years) and severe hypermetropia developed retinopathy with visual deterioration during two separate empiric trials of GH therapy. On the first occasion, a relatively high dose of GH (10.5 mg/m2/week) administered from age 4.4 to age 4.7 years was associated with the development of central serous retinopathy, resulting in marked reduction in visual acuity. On cessation of GH, the macular oedema resolved, and visual acuity improved. At age 5.6 years, GH therapy was re-introduced at a lower dose (3.9 mg/m2/week) and her vision monitored closely. Bilateral retinal oedema recurred after 3 months, and GH therapy was stopped. Once again, the macular oedema regressed, and visual acuity improved following withdrawal of GH. These ophthalmic changes contra-indicated further GH therapy.

CONCLUSION

We suggest that GH may be a risk factor in the development of retinopathy in certain non-diabetic patients, especially in the presence of a severe refractive error.

Low cumulative incidence of proliferative retinopathy in childhood-onset type 1 diabetes: a 24-year follow-up study

AIMS/HYPOTHESIS

We estimated cumulative incidence of proliferative diabetic retinopathy (PDR) and risk factors for developing diabetic retinopathy (DR) in childhood-onset type 1 diabetes.

MATERIALS AND METHODS

A sample of 294 patients with childhood-onset type 1 diabetes (<15 years) diagnosed in Norway between 1973 and 1982 was examined for retinopathy at baseline between 1989 and 1990 and at follow-up from 2002 to 2003. At follow-up, mean age was 33 years (range: 21-44), mean diabetes duration 24 years (19-30) and total person-time contributed 7,152 person-years. Retinal photographs were taken at baseline and follow-up. Associations between baseline factors and PDR were estimated using Cox regression models.

RESULTS

Overall, 262 of 294 (89.1%) developed DR from diabetes onset, of whom 31 developed PDR. The 25-year cumulative incidence of PDR was 10.9% (95% CI 7.3-14.5). Among 194 without retinopathy at baseline, 163 (84%) developed DR and nine (5%) progressed to PDR. Among 97 patients with non-proliferative DR at baseline, 19 (20%) progressed to PDR. Significant predictors for developing PDR were retinopathy at baseline (relative risk [RR]=3.71, 95% CI 1.59-8.68), HbA(1c) (RR=2.05, 1.44-2.93), and triglycerides (RR=1.55, 1.06-1.95).

CONCLUSIONS/INTERPRETATION

Nine out of every ten patients diagnosed with type 1 diabetes developed DR, but only one out of ten developed PDR within their first 25 years of diabetes duration. The cumulative incidence of PDR is lower than previously reported from other countries. Potentially modifiable risk factors predict the development of DR and PDR.

A multifocal electroretinogram model predicting the development of diabetic retinopathy

The prevalence of diabetes has been accelerating at an alarming rate in the last decade; some describe it as an epidemic. Diabetic eye complications are the leading cause of blindness in adults aged 25-74 in the United States. Early diagnosis and development of effective preventatives and treatments of diabetic retinopathy are essential to save sight. We describe efforts to establish functional indicators of retinal health and predictors of diabetic retinopathy. These indicators and predictors will be needed as markers of the efficacy of new therapies. Clinical trials aimed at either prevention or early treatments will rely heavily on the discovery of sensitive methods to identify patients and retinal locations at risk, as well as to evaluate treatment effects. We report on recent success in revealing local functional changes of the retina with the multifocal electroretinogram (mfERG). This objective measure allows the simultaneous recording of responses from over 100 small retinal patches across the central 45 degrees field. We describe the sensitivity of mfERG implicit time measurement for revealing functional alterations of the retina in diabetes, the local correspondence between functional (mfERG) and structural (vascular) abnormalities in eyes with early nonproliferative retinopathy, and longitudinal studies to formulate models to predict the retinal sites of future retinopathic signs. A multivariate model including mfERG implicit time delays and 'person' risk factors achieved 86% sensitivity and 84% specificity for prediction of new retinopathy development over one year at specific locations in eyes with some retinopathy at baseline. A preliminary test of the model yielded very positive results. This model appears to be the first to predict, quantitatively, the retinal locations of new nonproliferative diabetic retinopathy development over a one-year period. In a separate study, the predictive power of a model was assessed over one- and two-year follow-ups. This permitted successful prediction of new retinopathy development in eyes with and without retinopathy at baseline. Finally, we briefly describe our current research efforts to (a) locally predict future sight-threatening diabetic macular edema, (b) investigate local retinal function change in adolescent patients with diabetes, and (c) better understand the physiological bases of the mfERG delays. The ability to predict the retinal locations of future retinopathy based on mfERG implicit time provides clinicians a powerful tool to screen, follow-up, and even consider early prophylactic treatment of the retinal tissue in diabetic patients. It also aids identification of 'at risk' populations for clinical trials of candidate therapies, which may greatly reduce their cost by decreasing the size of the needed sample and the duration of the trial.

Lower-than-expected prevalence and severity of retinopathy in an incident cohort followed during the first 4-14 years of type 1 diabetes: the Wisconsin Diabetes Registry Study

The authors examined the development of diabetic retinopathy in a population-based cohort of persons with incident type 1 diabetes to investigate the possibility of lowered retinopathy prevalence and severity compared with previous US studies. A total of 474 diabetic persons from Wisconsin were followed from diagnosis through 4-14 years' duration during 1990-2002. Retinopathy was determined by fundus photography at 4, 7, 9, and 14 years' duration. Risk of developing retinopathy was modeled on demographic and diabetes-care characteristics by means of a generalized linear model using the complementary log-log link for interval-censored data. Prevalence of retinopathy increased with duration of diabetes, from 6% at 4 years to 73% at 14 years, and was highest among adults (> or =20 years of age). Risk of developing retinopathy increased with increasing duration, worse glycemic control, and age up to 20 years. Indicators of diabetes care were related to retinopathy through their effect on glycemic control. Improvements in diabetes care leading to better glycemic control may have contributed to the much lower prevalence and less severe retinopathy observed than expected on the basis of a previous report from the same region of Wisconsin. The observed decreased prevalence has important implications for persons with type 1 diabetes, since retinopathy is a serious microvascular complication.

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.

Telepaediatrics and diabetic retinopathy screening of young people with diabetes in Queensland

We have examined the feasibility of a telemedicine-enabled screening service for children and adolescents with diabetes in Queensland. There are approximately 1400 young people with diabetes in Queensland and only about two-thirds of them are screened in accordance with international guidelines. A regional retinal screening service was established using a nonmydriatic digital retinal camera. Seven centres volunteered to participate in the study. During a five-month pilot trial, 83 of the young people with diabetes who attend these centres underwent digital retinal screening (3.7%). Retinal images were sent via email to a paediatric ophthalmologist for review and results were returned via email. A copy of each participant's results was forwarded by mail to the referring diabetes doctor and the participant and family. The majority of the image files (96%) were rated as excellent or good. Only one participant was identified as having an abnormal result. Participants and their families expressed satisfaction with the digital retinal screening process.

The case for biennial retinopathy screening in children and adolescents

OBJECTIVE

Current guidelines recommend annual retinopathy screening 2 years after onset (for pubertal-onset type 1 diabetes) and after 5 years (or age 11, whichever is earlier) for prepubertal onset. Our aim was to describe the natural history of retinopathy and to explore optimal retinal screening intervals for children and adolescents (aged <20 years) screened according to these guidelines.

RESEARCH DESIGN AND METHODS

More than 1,000 children and adolescents, followed longitudinally, were screened for retinopathy using seven-field stereoscopic fundus photography through dilated pupils. Of these, 668 had baseline and follow-up retinal screening. Using generalized estimating equations, we compared the risk of retinopathy with baselines at yearly intervals, in older and younger groups, in higher risk groups (diabetes duration >10 years or HbA(1c) >10% at any screening), and after stratification </=10 and <10 years in duration.

RESULTS

After 1 year, retinopathy did not increase significantly in the older group (n = 618, median HbA(1c) 8.7%, range 8.0-9.5), younger group (n = 50, median HbA(1c) 8.5%, range 8.0-9.2), or the higher-risk groups. Retinopathy increased significantly after 2 years in the older group (P = 0.003) but not until 6 years in the younger group (P = 0.01). In the group with HbA(1c) >10% recorded at any visit, retinopathy increased significantly after 2 years (P = 0.001) but not until 3 years in the group whose HbA(1c) was always </=10% (P = 0.003). After the second eye assessment, retinopathy did not increase significantly until 3 and 6 years later in the older and younger groups, respectively (P = 0.028 and 0.014).

CONCLUSIONS

These results suggest that adolescents (in reasonable metabolic control) could safely be screened every 2 years rather than the currently recommended 1-year interval. In younger children, the next screening interval could be >2 years later. Individuals with especially poor control, duration >10 years, or significant retinopathy should be screened more frequently.

Epidemiology of diabetic retinopathy and macular oedema: a systematic review

AIMS

To systematically review the literature on the prevalence and incidence of diabetic retinopathy (DR) and macular oedema (MO).

METHODS

A search of the bibliographic databases (Medline, Embase, CINAHL) was conducted up to October 2001. Selected relevant studies were scrutinized and included in the review.

RESULTS

A total of 359 studies were included. The studies were reported in nearly 100 different journals and in over 50 countries. The majority of the studies were US-based, with large studies such as the Wisconsin Epidemiologic Study of Diabetic Retinopathy dominating the literature. The studies were quite dated and highly heterogeneous in nature in terms of patient selection with variable inclusion criteria (age range, gender, diabetes duration and type, ethnicity, comorbidity, and DR status, assessment, and classification).

CONCLUSIONS

There are inconsistencies between epidemiological studies, and differences in study methods may contribute to conflicting reports of prevalence and incidence of DR and MO in diabetic populations. As new therapies for DR and its associated complications emerge, the need to capture and monitor new epidemiological data becomes increasingly important to be able to assess the impact and effectiveness of these therapies. Robust, longitudinal capture of patient data is, therefore, essential to evaluate the impact of current practice on the epidemiology of diabetic eye complications.

Pre-pubertal onset of type 1 diabetes and appearance of retinopathy

OBJECTIVES

It was suggested that the years of diabetes preceding puberty may not contribute to the development of retinopathy but evidence for this is conflicting. To verify the influence of pre-pubertal diabetes, we compared the correlations between prevalence of retinopathy and diabetes duration in patients who developed type 1 diabetes before and after puberty.

METHODS

Six hundred and twenty-eight patients with diabetes onset at age< or =29, on insulin treatment and aged< or =60 at the time of screening for retinopathy were considered retrospectively. Pre-pubertal age was defined as 0-12 in males and 0-11 in females. Two hundred patients had developed diabetes before puberty and 428 after puberty. Screening was by ophthalmoscopy + 35 mm photography or digital photography.

RESULTS

Prevalence of retinopathy was lower among patients with pre-pubertal onset and diabetes durations 10-14 and 15-19 years (p=0.006 and p=0.003, respectively) but prevalence rates became similar after 20 yrs duration.

CONCLUSION

That retinopathy is infrequent and mild during childhood, is probably due to the short duration of diabetes rather than a specific protective effect of pre-puberty. After 20 years' duration, however, the prevalence of retinopathy is no longer influenced by age at onset, suggesting that, in the longer term, pre-pubertal years do contribute to the onset of retinopathy.

Early glycemic control, age at onset, and development of microvascular complications in childhood-onset type 1 diabetes: a population-based study in northern Sweden

OBJECTIVE

The aim of this work was to study the impact of glycemic control (HbA(1c)) early in disease and age at onset on the occurrence of incipient diabetic nephropathy (MA) and background retinopathy (RP) in childhood-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

All children, diagnosed at 0-14 years in a geographically defined area in northern Sweden between 1981 and 1992, were identified using the Swedish Childhood Diabetes Registry. From 1981, a nationwide childhood diabetes care program was implemented recommending intensified insulin treatment. HbA(1c) and urinary albumin excretion were analyzed, and fundus photography was performed regularly. Retrospective data on all 94 patients were retrieved from medical records and laboratory reports.

RESULTS

During the follow-up period, with a mean duration of 12 +/- 4 years (range 5-19), 17 patients (18%) developed MA, 45 patients (48%) developed RP, and 52% had either or both complications. A Cox proportional hazard regression, modeling duration to occurrence of MA or RP, showed that glycemic control (reflected by mean HbA(1c)) during the follow-up was significantly associated with both MA and RP when adjusted for sex, birth weight, age at onset, and tobacco use as potential confounders. Mean HbA(1c) during the first 5 years of diabetes was a near-significant determinant for development of MA (hazard ratio 1.41, P = 0.083) and a significant determinant of RP (1.32, P = 0.036). The age at onset of diabetes significantly influenced the risk of developing RP (1.11, P = 0.021). Thus, in a Kaplan-Meier analysis, onset of diabetes before the age of 5 years, compared with the age-groups 5-11 and >11 years, showed a longer time to occurrence of RP (P = 0.015), but no clear tendency was seen for MA, perhaps due to lower statistical power.

CONCLUSIONS

Despite modern insulin treatment, >50% of patients with childhood-onset type 1 diabetes developed detectable diabetes complications after approximately 12 years of diabetes. Inadequate glycemic control, also during the first 5 years of diabetes, seems to accelerate time to occurrence, whereas a young age at onset of diabetes seems to prolong the time to development of microvascular complications.

Diabetes mellitus and retinopathy

The role of somatostatin and growth hormone in eye diseases recently became a matter of interest because of its link with proliferative diabetic retinopathy. In diabetic patients the pathologic proliferation of blood vessels as a result of retinal ischemia is a major cause of blindness. The hypoxic portions of the retina release angiogenic factors, stimulating neovascularization. Somatostatin is a natural peptide hormone that affects the release of a number of other hormones, such as growth hormone, glucagon, insulin and gastrin. The somatostatin analog promises to be safe and effective treatment for severe diabetic retinopathy. This compound has been shown to block the local and systemic production of insulin-like growth factor 1 and growth hormone, which promote the angiogenesis and endothelial cell proliferation associated with proliferative retinopathy. Several studies have confirmed that using somatostatin analogs to block insulin-like growth factor 1 production is effective in reducing neovascularization and preventing disease progression to proliferative stage of diabetic retinopathy. Long-acting somatostatin analogs are currently being tested for the treatment of diabetic retinopathy. The development of somatostatin analogs with increased selectivity for receptor subtypes will provide improved outcomes in the management of patients with diabetic retinopathy.

Diabetes: classification and strategies for integrated care

This article is the third in a series of three in-depth literature reviews on diabetes. The first article (Vol 12(18): 1091-5) detailed the history of diabetes from the first recorded mention of the disease in the Ebers papyrus through to the discovery of insulin. The second (Vol 12(19): 1137-41) dealt with the history of insulin over the past 80 years and the development of possible alternatives. This final article in the series details the new classifications for diabetes and addresses the aetiology, pathophysiology and complications of the disease. While discussing both type 1 and type 2 diabetes, the article concentrates on the newly defined type 1 diabetes mellitus. An examination of the recently released National Service Framework for Diabetes: Delivery Strategy (DoH, 2003) is included, healthcare provision is discussed, as is the role of the diabetes specialist nurse. An insight is given into the challenges and opportunities available for healthcare practitioners to work in partnership to reform the way in which diabetes services are managed.

Retinopathy in juvenile diabetes: a 10-year (1990-2000) review

Diabetic retinopathy (DR) is the most frequent complication of diabetes and a leading cause of impaired vision in the Western world. There is general agreement that early diagnosis and treatment of DR can slow its progression and help to prevent blindness. However, as a result of its asymptomatic nature and its etiopathogenesis, which is still unclear due to its multifactorial complexity, DR-related blindness has a growing social impact in industrialized countries. Therefore, in order to gain a better understanding of this serious disease, the author performed an updated 10-year review of risk factors and management of DR in type 1 diabetes.

Diabetic retinopathy in childhood: long-term follow-up by fluorescein angiography beginning in the first months of disease

BACKGROUND

Little is known about minimal retinal lesions occurring in the first months of disease in children with type 1 diabetes mellitus (DM).

OBJECTIVE

To detect any early retinal change and to evaluate its progression in children diagnosed with type 1 DM.

PATIENTS

From 1979 to 1997 we examined by fluorescein angiography at diagnosis or within 15 months from the onset of DM 130 young patients with type 1 DM (mean age at diagnosis 10.08 +/- 2.62 yr). In 112 patients follow-up by fluorescein angiography was performed every 1.26 years with a mean of 5.41 fluorescein angiographies/patient.

METHODS

The stage of retinopathy was graded to detect minimal lesions. We also considered sex, pubertal stage, HLA, family history of DM, disease duration and HbA1c levels.

RESULTS

At first examination, 14 out of 127 (11%) readable angiographies showed minimal retinal changes. There was no statistically significant difference between the patients with or without lesions for all parameters considered. The 112 patients examined during follow-up were divided as follows: Group A: no retinopathy at first examination; Group A1: no retinopathy during follow-up; Group A2: retinal changes during follow-up; Group B: retinal changes at the first examination. Mean HbA1c value evaluated during the whole follow-up was lower in group A1 than in group A2. HbA1c levels at onset of the disease were significantly different in the three groups: in group A1 it was lower than in group A2 and in group B.

CONCLUSIONS

The presence of early lesions in the first year of disease in 11% of patients is probably due to the method of examination, which may detect even minimal retinal changes. This may be correlated to the acute metabolic failure present at the onset of disease. The prolonged follow-up seems to demonstrate that the early changes are not necessarily a negative prognostic factor in the evolution of diabetic retinopathy. We confirm that duration of DM and metabolic control are the main factors influencing the course of retinopathy in these young patients. Early fluorescein angiography is not particularly useful in the management of children with DM.

Relationship between elastin-derived peptides and the development of microvascular complications: a longitudinal study in children with Type 1 (insulin-dependent) diabetes mellitus

Levels of elastin-derived peptides (EDP) were determined by enzyme-linked immunosorbent assay (ELISA) in sera of 28 children with Type 1 (insulin-dependent) diabetes mellitus (mean age 11.6+/-2.8 years, diabetes duration 5.1+/-2.5 years). None of the children had clinical or laboratory evidence of vascular complications. The children were followed over a period of 6 years, and 24 healthy children of similar age and sex served as a control group. During the investigative period, 10 diabetic patients had increased EDP levels, with 9 having been diabetic for more than 5 years and 1 patient less than 5 years. Seven of these patients developed diabetic microvascular complications. In this group, EDP were independently associated with age (r=.39, P=.047), retinopathy (r=.48, P=.034), and antibodies to advanced glycation endproducts (AGE) (r=.52, P=.018). The data of this pilot study are not strong enough to appear that EDP are a useful predictor of subsequent development of microvascular complications. This may be due to the small number of subjects, short duration of the study, manner in which EDP or the endpoints were measured, or frequency of which EDP measurements were made. Further prospective and longer studies of larger populations are needed to identify the role of EDP as an early marker for the development of diabetic microvascular complications.

How do the results of the diabetes control and complications trial relate to the practice of pediatrics: who should have intensive management?

The DCCT showed that any improvement in glycemic control decreases the risk of long-term complications. Although expensive, time consuming, and associated with increased risks of hypoglycemia and obesity, improved glycemic control is of benefit as long as hypoglycemia is avoided. Specific HbA1c target levels must be individualized and age appropriate.

Diabetes complication screening in 937 children and adolescents

Results are presented of diabetes complication screening in children and adolescents aged 6-20 years. Their diabetes duration was 0.02-18.4 yr and median HbA1c over the preceding 36 months was 8.4% [IQR 7.8-9.3]. Gradable retinal photographs were obtained in 937: 110 less than 11 years (< 11 yr Gp). Albumin excretion rate (AER) was obtained from 3 timed overnight urine collections in 691: 100 in < 11 yr Gp. Early retinopathy was found in 27% (9% in < 11 yr Gp). Microalbuminuria (AER > or = 20 micrograms/min) was found in 4%. Significant individual risk factors for both complications were higher blood pressure, cholesterol, HbA1c, pubertal staging, older age and longer diabetes duration. Using multiple logistic regression, significant risk factors for retinopathy were longer duration and older age and in addition higher HbA1c. Diabetes complication screening detected early subclinical disease in children and adolescents who may benefit from lowering blood pressure and improving metabolic control. Screening should commence after five years of duration in young children, and after two years of duration in adolescents.

Monitoring for retinopathy in children and adolescents with type 1 diabetes

In children with an average diabetes onset at 11 y of age, the first retinal changes can be expected after a median diabetes duration of 9 y, while the median time until clinically relevant background retinopathy is 14 y. Periodic examinations of the retinal status become necessary with the onset of puberty or after 5 y of diabetes duration. Only sensitive methods should be used for retinopathy screening; the minimum recommended standard is a stereoscopic slit-lamp biomicroscopic examination in mydriasis. The degree of glycaemic control, both before and after puberty, appears to be of outstanding importance for the development of retinopathy, but the contribution of other factors (arterial blood pressure, lipid abnormalities, sex steroids, smoking and genetic factors) may be of varying relevance in the individual patient. Thus, to improve the long-term prognosis for children with diabetes appropriate screening for retinopathy and associated risk factors is mandatory.

Diabetic retinopathy in pediatric patients with type-1 diabetes: effect of diabetes duration, prepubertal and pubertal onset of diabetes, and metabolic control

OBJECTIVE

The objective of this study was to determine the contribution of prepubertal and pubertal onset and duration of diabetes to the development of diabetic retinopathy.

STUDY DESIGN

A total of 1391 standardized fundus examinations (stereo fundus-photography) were performed in 441 children or adolescents with type-1 diabetes (median age 15.5 years, median duration of diabetes 6.3 years).

RESULTS

Mild nonproliferative retinopathy was present in 72 patients (median age 19.9 years). Life table analysis revealed a median duration of diabetes until retinopathy was first diagnosed at 16.6 years (95% confidence interval: 15.3 to 18.3). Patients were stratified according to diabetes onset before or in puberty (> or = 10.4 years in girls, > or = 12.2 years in boys). In children with a prepubertal onset of diabetes, retinopathy occurred after a pubertal duration of 10.9 years compared with 15.1 years in children with onset of diabetes in puberty (p < 0.01), demonstrating the additional risk conveyed by the prepubertal years of diabetes. Long-term metabolic control had a significant influence on the prevalence of retinopathy: patients with a median HbA1c > or = 7.5% had development of retinopathy on average after 15.5 years compared with 18.3 years in patients with lower HbA1c values (p < 0.05).

CONCLUSION

Both prepubertal and pubertal duration of diabetes are relevant for the development of background retinopathy. Good metabolic control should be attempted irrespective of age.

Randomised placebo-controlled trial of human recombinant insulin-like growth factor I plus intensive insulin therapy in adolescents with insulin-dependent diabetes mellitus

BACKGROUND

Good glycaemic control in insulin-dependent diabetes mellitus (IDDM) to prevent complications may be difficult to achieve during adolescence, because abnormalities in production of growth hormone or insulin-like growth-factor-I (IGF-I) can lead to lower insulin sensitivity. Recombinant human IGF-I (rhIGF-I) given as an adjunct to insulin therapy in IDDM, might improve glycaemic control in adolescents; we investigated the effects of the addition of IGF-I in a randomised, double-blind, placebo-controlled trial.

METHODS

53 patients with IDDM (26 male, 27 female) with a median age of 16.1 years (range 10.8-20.6) and diabetes of more than 2 years' duration were randomly assigned subcutaneous rhIGF-I (20 or 40 microg/kg daily [n=18, n=18, respectively]) or placebo (n=17), both in addition to multiple-injection insulin therapy for 24 weeks. The primary endpoint, glycated haemoglobin (HbA1c) and routine biochemistry were measured every 4 weeks. Retinal photographs and glomerular-filtration rates were assessed at base line and at the end of the study. Data were analysed by intention to treat.

FINDINGS

With a dose of 40 microg/kg rhIGF-I daily, we found significant reductions in HbA1c compared with placebo (p=0.03), without changes in body-mass index, rate of hypoglycaemia, insulin dose, or circulating concentrations of IGF-binding proteins 1 and 3. The greatest median change in HbA1c of -0.6% (range -2.8 to -1.5%) was seen with rhIGF-I 40 microg/kg at week 12, but was not sustained at week 24. The greatest reductions in HbA1c at week 24 were seen among patients with the greatest changes in IGF-I concentrations (r=-0442, p=0.002). Retinal photographs, renal function (glomerular filtration rate and urinary albumin excretion), and routine biochemistry showed no adverse events.

INTERPRETATION

Our data confirm that rhIGF-I as an adjunct to insulin therapy can improve HbA1c values in adolescents with IDDM without overt toxic effects, but they raise questions about whether these effects can be sustained in cases of poor compliance or reduced bioefficacy.