Improving visual prognosis of the diabetic patients during the past 30 years based on the data of the Finnish Register of Visual Impairment

Global certification of visual impairment registries: A scoping review

BACKGROUND

Visual impairment is a global problem which is predicted to rise in the coming years. Some of the biggest causes of visual impairment globally include uncorrected refractive error, cataract and age-related macular degeneration. People with a visual impairment often require support and so many countries hold registers of visual impairment. These registers can sit at a national, regional or local level. This scoping review aims to identify which countries hold visual impairment registries and have published data from them.

METHODS

Medline All, Embase and EBSCOHost were searched using several search terms after consulting an information specialist. All papers after the year 2000 were included in the scoping review. All results are shown using a PRISMA diagram and presented narratively.

RESULTS

The total number of articles and papers identified was 1266; after screening and review, 57 articles were included in the review from 2000 to 2024. These articles came from 19 different countries and encompassed national, regional and local visual impairment databases. Many countries cited age-related macular degeneration as the major cause of blindness with diabetic retinopathy and glaucoma following. In less economically developed countries, refractive error was the main cause of sight loss. There were papers which focused on specific eye conditions such as glaucoma and diabetic retinopathy or on specific cohorts including working-age population and children. The leading causes of blindness in children appeared to be inherited retinal diseases, albinism and cerebral visual impairment.

CONCLUSION

Certification of visual impairment is held differently across the world. There is commonality among different countries regarding the major causes of visual impairment in both adults and children. The importance of holding visual impairment registers to support people with a visual impairment and to plan services is essential.

Long-term results of cataract surgery in type 2 diabetics, a 20-year prospective longitudinal study

PURPOSE

To investigate the 20-year outcome, in best-corrected visual acuity (BCVA), and subjective visual function (VF-questionnaire, VF-14) after cataract surgery in type 2 diabetics, compared with non-diabetics.

METHODS

109 type 2 diabetics and 698 non-diabetics, who had cataract surgery during 1 year at one institution, were included in this prospective, longitudinal, population-based cohort study. BCVA and VF-14 responses were recorded pre- and postoperatively, and every 5 years up to 20 years after surgery. Retinopathy was graded before surgery.

RESULTS

There was no significant difference between diabetics and non-diabetics, in change in BCVA from 10 years or more after surgery, p = 0.45, p = 0.44 and p = 0.83, at 10, 15 and 20 years, respectively, as well as in self-perceived visual function (VF-14) at any time after surgery, p = 0.72, p = 0.20 and p = 0.78, 10-20 years, respectively. At any follow-up, there was no significant difference in BCVA in relation to retinopathy level before surgery, p = 0.1 at 20 years. There was a trend from 10 years after surgery and onward that patients with no retinopathy at baseline lost fewer letters during the 20 years than diabetics with retinopathy. Patients with known type 2 diabetes at surgery had a significantly lower survival compared with the non-diabetics at each follow-up, p = 0.003.

CONCLUSION

In surviving diabetics, BCVA and subjective visual function were retained in most cases up to 20 years after cataract surgery. Cataract extraction is effective in causing a sustainable improvement in visual function also in type 2 diabetics. Knowledge of these long-term outcomes is essential when counselling diabetics for cataract surgery.

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Changes in the Epidemiology of Diabetic Retinopathy in Spain: A Systematic Review and Meta-Analysis

Background. The aim of the present study was to determine the prevalence and incidence of diabetic retinopathy (DR) and its changes in the last 20 years in type 2 diabetes mellitus (T2DM) patients in Spain. Methods. A systematic review with a meta-analysis was carried out on the studies published between 2001–2020 on the prevalence and incidence of DR and sight-threatening diabetic retinopathy (STDR) in Spain. The articles included were selected from four databases and publications of the Spanish Ministry of Health and Regional Health Care System (RHCS). The meta-analysis to determine heterogeneity and bias between studies was carried out with the MetaXL 4.0. Results. Since 2001, we have observed an increase in the detection of patients with DM, and at the same time, screening programs for RD have been launched; thus, we can deduce that the increase in the detection of patients with DM, many of them in the initial phases, far exceeds the increased detection of patients with DR. The prevalence of DR was higher between 2001 and 2008 with values of 28.85%. These values decreased over the following period between 2009 and 2020 with a mean of 15.28%. Similarly the STDR prevalence decrease from 3.67% to 1.92% after 2008. The analysis of the longitudinal studies determined that the annual DR incidence was 3.83%, and the STDR annual incidence was 0.41%. Conclusion. In Spain, for T2DM, the current prevalence of DR is 15.28% and 1.92% forSTDR. The annual incidence of DR is 3.83% and is 0.41% for STDR.

Long-term trends in incidence and prevalence of severe sight impairment due to diabetes in South East Scotland before and after implementation of diabetic retinopathy screening

The study set out to examine the impact of the introduction of a national diabetic retinopathy screening programme in Scotland in 2006 on incidence and trends in severe sight impairment (SSI) certification due to diabetes over three decades.

We analysed SSI certification due to diabetic eye disease in Fife, Scotland, between 2010 and 2019 and compared it to previously published estimates from 1990 onwards. Population estimates of the general population and those with diabetes were obtained from the National Records of Scotland and the National Diabetes Register, NHS SCI Diabetes, respectively. Mean annual incidence of SSI in the population with diabetes, 1990–2019, before and after the introduction of diabetic retinopathy screening was compared using a Mann–Whitney U Test.

Mean incidence in 2007–2019 was 19.8/100,000 and was significantly less than the period before the systematic screening, 1990–2006 (57.5/100,000, p < .001). Mean SSI incidence due to diabetes in Fife between 2010 and 2019 was significantly lower than in the previous decades ( p < .001) at 16.4 per 100,000 for the population with diabetes, per year ( SD 10.0; 95% confidence interval: [9.2, 23.5]) compared to 42.7 per 100,000 in 2000–2009 and 64.3 per 100,000 in 1990–1999.

This study demonstrates a significant reduction in the annual incidence of SSI due to diabetes before and after the introduction of the screening programme provides evidence for the benefit of systematic diabetic retinopathy screening programmes. Other factors including improved management of diabetes and risk factors will have also had an impact emphasizing the importance of a multidisciplinary approach to the prevention of sight loss in diabetes.

Diabetic retinopathy and visual impairment in a Norwegian diabetic coast population with a high dietary intake of fish oils. An observational study

PURPOSE

To present retinal and visual findings in a Norwegian west coast diabetic population and to elucidate the effect of dietary intake of marine polyunsaturated fatty acids (PUFAs) on the development of diabetic retinopathy (DR).

METHODS

In an eye practice in an archipelago of 314 km², serving a population of about 40 000, we recorded the prevalence of visual impairment and DR in a referred diabetic population. 510 consecutive patients were included, 238 females and 272 males. 50 patients had type I and 460 had type II diabetes mellitus (DM). Self-reported medication, diet supplements, HbA1c and fish consumption were registered.

RESULTS

In the type I group, the median age was 44.5 and median DM duration 11.5 years [1-44]. 48% had photographic evidence of DR, 8 patients (16%) had proliferative retinopathy (PDR), and 6 patients (12%) had diabetic macular oedema (DME). All had best-corrected visual acuity (BCVA) of 0.5 (log MAR 0.3) or better in the best eye. In the type II group, the median DM duration was 8 years [1-53], and median age was 66. 98% had best eye BCVA at or better than 0.5 (log MAR 0.3) in the best eye.

CONCLUSION

None of the 510 patients had BCVA worse than 0.3 (log MAR 0.48) due to diabetic retinopathy. Compared to similar studies, we found a very low visual impairment rate. A possible protective effect of PUFA on the prevalence and progression of diabetic microangiopathy including retinopathy is discussed.

Diabetic Retinopathy Screening and Registration in Europe-Narrative Review

Diabetic retinopathy (DR) is a leading cause of preventable vision impairment and blindness in the European Region. Despite the fact that almost all European countries have some kind of prophylactic eye examination for people with diabetes, the examinations are not properly arranged and are not organized according to the principles of screening in medicine. In 2021, the current COVID-19 pandemic moved telemedicine to the forefront healthcare services. Due to that, a lot more patients could benefit from comfortable and faster access to ophthalmology specialist care. This study aimed to conduct a narrative literature review on current DR screening programs and registries in the European Union for the last 20 years. With the implementation of telemedicine in daily medical practice, performing screening programs became much more attainable. Remote assessment of retinal pictures simultaneously saves countries time, money, and other resources.

The contribution of the English NHS Diabetic Eye Screening Programme to reductions in diabetes-related blindness, comparisons within Europe, and future challenges

The aim of the English NHS Diabetic Eye Screening Programme (DESP) is to reduce the risk of sight loss amongst people with diabetes by the prompt identification and effective treatment if necessary of sight-threatening diabetic retinopathy, at the appropriate stage during the disease process, with a long-term aim of preventing blindness in people with diabetes.For the year 2009-2010, diabetic retinopathy (DR) was no longer the leading cause of blindness in the working age group. There have been further reductions in DR certifications for WHO severe vision impairment and blindness from 1,334 (5.5% of all certifications) in 2009/2010 to 840 (3.5% of all certifications) in 2018/2019. NHS DESP is a major contributor to this further reduction, but one must also take into account improvements in glycaemic and blood pressure control, timely laser treatment and vitrectomy surgery, improved monitoring techniques for glycaemic control, and vascular endothelial growth factor inhibitor injections for control of diabetic macular oedema. The latter have had a particular impact since first introduced in the UK in 2013.Current plans for NHS DESP include extension of screening intervals in low-risk groups and the introduction of optical coherence tomography as a second line of screening for those with screen positive maculopathy with two dimensional markers. Future challenges include the introduction of automated analysis for grading and new camera technologies.

Prostaglandin E2 promotes pathological retinal neovascularisation via EP4R-EGFR-Gab1-AKT signaling pathway

Proliferative retinopathies, such as proliferative diabetic retinopathy (PDR) and retinopathy of prematurity (ROP) are major causes of visual impairment and blindness in industrialized countries. Prostaglandin E2 (PGE2) is implicated in cellular proliferation and migration via E-prostanoid receptor (EP4R). The aim of this study was to investigate the role of PGE2/EP4R signaling in the promotion of retinal neovascularisation. In a streptozotocin (STZ)-induced diabetic model and an oxygen-induced retinopathy (OIR) model, rats received an intravitreal injection of PGE2, cay10598 (an EP4R agonist) or AH23848 (an EP4R antagonist). Optical coherence tomography, retinal histology and biochemical markers were assessed. Treatment with PGE2 or cay10598 accelerated pathological retinal angiogenesis in STZ and OIR-induced rat retina, which was ameliorated in rats pretreated with AH23848. Serum VEGF-A was upregulated in the PGE2-treated diabetic rats vs non-treated diabetic rats and significantly downregulated in AH23848-treated diabetic rats. PGE2 or cay10598 treatment also significantly accelerated endothelial tip-cell formation in new-born rat retina. In addition, AH23848 treatment attenuated PGE2-or cay10598-induced proliferation and migration by repressing the EGF receptor (EGFR)/Growth factor receptor bound protein 2-associated binder protein 1 (Gab1)/Akt/NF-κB/VEGF-A signaling network in human retinal microvascular endothelial cells (hRMECs). PGE2/EP4R signaling network is thus a potential therapeutic target for pathological intraocular angiogenesis.

SWATH-MS Proteomic Analysis of Oxygen-Induced Retinopathy Reveals Novel Potential Therapeutic Targets

Purpose

Oxygen-induced retinopathy (OIR) is the most widely used model for ischemic retinopathies such as retinopathy of prematurity (ROP), proliferative diabetic retinopathy (PDR), and retinal vein occlusion (RVO). The purpose of this study was to perform the most comprehensive characterization of OIR by a recently developed technique, sequential window acquisition of all theoretical mass spectra (SWATH-MS) proteomics.

Methods

Control and OIR retina samples collected from various time points were subjected to SWATH-MS and detailed data analysis. Immunohistochemistry from mouse retinas as well as neovascular membranes from human PDR and RVO patients were used for the detection of the localization of the proteins showing altered expression in the retina and to address their relevance to human ischemic retinopathies.

Results

We report the most extensive proteomic profiling of OIR to date by quantifying almost 3000 unique proteins and their expression differences between control and OIR retinas. Crystallins were the most prominent proteins induced by hypoxia in the retina, while angiogenesis related proteins such as Filamin A and nonmuscle myosin IIA stand out at the peak of angiogenesis. Majority of the changes in protein expression return to normal at P42, but there is evidence to suggest that proteins involved in neurotransmission remain at reduced level.

Conclusions

The results reveal new potential therapeutic targets to address hypoxia-induced pathological angiogenesis taking place in number of retinal diseases. The extensive proteomic profiling combined with pathway analysis also identifies novel molecular networks that could contribute to the pathogenesis of retinal diseases.

Visual impairment and mortality in patients with type 2 diabetes

OBJECTIVE

To evaluate whether visual acuity impairment was an independent predictor of mortality in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This is a 19-year follow-up of a cohort of 1241 patients newly diagnosed with type 2 diabetes and aged 40 years or over. Visual acuity was assessed by practicing ophthalmologists both at diabetes diagnosis and after 6 years. The logarithmic value of the visual acuity (logMAR) was the exposure. Multivariable Cox regression models were adjusted for multiple potential confounders including cardiovascular disease, and censored for potential mediators, that is, fractures/trauma. Primary outcomes were from national registers: all-cause mortality and diabetes-related mortality.

RESULTS

Visual impairment at diabetes diagnosis was robustly associated with subsequent 6-year all-cause mortality. Per 1 unit reduced logMAR acuity the incidence rate of all-cause mortality increased with 51% (adjusted HR: 1.51; 95% CI 1.12 to 2.03) and of fractures/trauma with 59% (HR: 1.59; 95% CI 1.18 to 2.15), but visual acuity was not associated with diabetes-related mortality. After censoring for fractures/trauma, visual acuity was still an independent risk factor for all-cause mortality (HR: 1.68; 95% CI 1.23 to 2.30). In contrast, visual acuity 6 years after diabetes diagnosis was not associated with the subsequent 13 years' incidence of any of the outcomes, as an apparent association with all-cause mortality and diabetes-related mortality was explained by confounding from comorbidity.

CONCLUSIONS

Visual acuity measured by ophthalmologists in patients newly diagnosed with type 2 diabetes was an independent predictor of mortality in the short term.

Early glycaemic control for maintaining visual function in type 1 diabetes: The Oulu cohort study of diabetic retinopathy

PURPOSE:

The purpose of this study was to evaluate the visual function and the ophthalmic status of young Finnish adults with long duration of type 1 diabetes in relation to the history of the metabolic control.

METHODS:

A population-based cohort of children with type 1 diabetes examined in the Northern Ostrobothnia hospital district in 1989 (n = 216) was re-examined 18 years later. High-contrast visual acuity (best-corrected visual acuity), contrast sensitivity, refractive error, lens status, intraocular pressure, stage of diabetic retinopathy and received treatments were evaluated. The metabolic control was reflected by the mean of glycated haemoglobin A1 or glycated haemoglobin A1c values of the years 1983-1989 and 1992-2007, respectively.

RESULTS:

In all, 96 men and 76 women age 30 ± 3 years with type 1 diabetes duration of 23 ± 4 years attended the re-evaluation. About 60% (103/172) had normal best-corrected visual acuity and 3% had low vision. Contrast sensitivity was abnormal in two-thirds. Half had myopia. Four patients had cataract surgery. Low childhood glycated haemoglobin A1 was indicative, and favourable glycated haemoglobin A1c during youth was a significant predictor of better contrast sensitivity and ocular state in adulthood.

CONCLUSION:

The majority of the patients have useful vision, although minor functional impairments are commonly detectable. Long duration of type 1 diabetes in association with non-optimal glycaemic control threatens visual function already at young adulthood. Thus, strong emphasis to control diabetes from onset is important in maintaining good visual function.

Visual impairment certification due to diabetic retinopathy in North and Eastern Devon

PURPOSE

To determine certifications of visual impairment (CVIs) due to diabetic retinopathy (DR) in a region that has operated diabetic screening since 1992.

METHODS

A retrospective review of all CVIs due to DR was conducted, with mid-year population estimates and a diabetes prevalence model used to determine the annual incidence of certification from 2010 to 2013. For 2013, CVIs due to DR were also compared to all CVIs in the region.

RESULTS

The total number of certifications due to DR was 75; 52 were sight impaired (SI) and 23 severely sight impaired (SSI) certifications; 25% of patients had type 1, and 75% had type 2 diabetes mellitus. The mean age at time of CVI was 65.5 years. The mean duration of known diabetes was 22.0 years. The incidence of CVI due to DR ranged from 30.8 to 77.4 per million population per year between 2010 and 2013. The incidence of CVI in the diabetic population was estimated at 0.47 to 1.21 per 1000 patients per year with diabetes for 2010-2013. In 2013, DR was a main or contributing cause in 4.3% of all CVIs, but did not contribute to any SSI certifications in the working age population.

CONCLUSION

The incidence of CVI due to DR was comparable to that reported in other regions. Nationwide, DR was the second most common cause of blindness in working age adults, but did not contribute to any SSI certifications in our population. Our results are consistent with the success of a long-standing retinal screening programme.

The role of retinopathy distribution and other lesion types for the definition of examination intervals during screening for diabetic retinopathy

PURPOSE

It has previously been shown that the intervals between screening examinations for diabetic retinopathy can be optimized by including individual risk factors for the development of the disease in the risk assessment. However, in some cases, the risk model calculating the screening interval may recommend a different interval than an experienced clinician. The purpose of this study was to evaluate the influence of factors unrelated to diabetic retinopathy and the distribution of lesions for discrepancies between decisions made by the clinician and the risk model.

METHODS

Therefore, fundus photographs from 90 screening examinations where the recommendations of the clinician and a risk model had been discrepant were evaluated. Forty features were defined to describe the type and location of the lesions, and classification and ranking techniques were used to assess whether the features could predict the discrepancy between the grader and the risk model.

RESULTS

Suspicion of tumours, retinal degeneration and vascular diseases other than diabetic retinopathy could explain why the clinician recommended shorter examination intervals than the model. Additionally, the regional distribution of microaneurysms/dot haemorrhages was important for defining a photograph as belonging to the group where both the clinician and the risk model had recommended a short screening interval as opposed to the other decision alternatives.

CONCLUSIONS

Features unrelated to diabetic retinopathy and the regional distribution of retinal lesions may affect the recommendation of the examination interval during screening for diabetic retinopathy. The development of automated computerized algorithms for extracting information about the type and location of retinal lesions could be expected to further optimize examination intervals during screening for diabetic retinopathy.