Individualised screening for diabetic retinopathy with proliferative retinopathy and macular oedema as separate end points.

PURPOSE: A number of algorithms have been developed to calculate screening intervals for diabetic retinopathy on the basis of individual risk factors. However, these approaches have not considered proliferative diabetic retinopathy (PDR) and diabetic macular oedema (DME) as separate end points and death as competing risk. METHODS: A multi-state survival model with death as competing risk was used to predict the screening interval for diabetic retinopathy based on information about all 2446 patients from a well-defined population who had started treatment for either PDR or DME during 25 years. The performance of the model was tested on the existing database and at seven screening sites on patients who had not developed a treatment requiring condition. RESULTS: Testing on the existing database showed that at a risk level of 2% the algorithm could predict a screening interval with a success rate higher than 90% and a 1.75 times average prolongation of the screening interval without failing to detect the development of verified PDR og DME. The model was limited to a diabetes duration shorter than 40 years and depended on knowledge of relevant risk factors. At the other participating screening sites the algorithm predicted shorter intervals than the screener. CONCLUSIONS: Algorithms for individualised screening for diabetic retinopathy can prolong screening intervals without losing patients who develop a vision threatening condition. The calculation of screening intervals requires access to relevant risk factors and should be developed on large data sets that reflect the population in which the algorithm should be used.

Risk of Diabetic Retinopathy According to Subtype of Type 2 Diabetes.

Type 2 diabetes is a heterogeneous disease that can be subdivided on the basis of ß-cell function and insulin sensitivity. We investigated the presence, incidence, and progression of diabetic retinopathy (DR) according to subtypes of type 2 diabetes. In a national cohort, we identified three subtypes of type 2 diabetes: classical, hyperinsulinemic, and insulinopenic type 2 diabetes, based on HOMA2 measurements. From the Danish Registry of Diabetic Retinopathy we extracted information on level of DR. We used several national health registries to link information on comorbidity, medications, and laboratory tests. We found individuals with hyperinsulinemic type 2 diabetes were less likely to have DR at entry date compared with those with classical type 2 diabetes, whereas individuals with insulinopenic type 2 diabetes were more likely to have DR. In multivariable Cox regression analysis, individuals with hyperinsulinemic type 2 diabetes had a decreased risk of both incidence and progression of DR compared to those with classical type 2 diabetes. We did not find any clear difference in risk of incident or progression of DR in individuals with insulinopenic compared to classical type 2 diabetes. These findings indicate that subcategorization of type 2 diabetes is important in evaluating the risk of DR.

Presence and development of diabetic retinopathy in 16 999 patients with type 1 diabetes in the Danish Registry of Diabetic Retinopathy.

PURPOSE: To evaluate the five-year incidence of diabetic retinopathy (DR) and associated risk markers in patients with type 1 diabetes in the national Danish DR-screening programme. METHODS: Based on national data, we included all 16 999 patients with type 1 diabetes in the Danish Registry of Diabetic Retinopathy, who attended the national screening programme in the period 2013-2018. According to the worse eye at first screening, DR was classified (levels 0-4) and linked with various national health registries to retrieve information on diabetes duration, systemic comorbidity, and medication. RESULTS: At first screening, median age and duration of diabetes were 45.0 and 16.7 years, and 57.5% were males. The prevalence and five-year incidences for DR and progression to proliferative DR (PDR) were 44.2%, 8.9% and 2.0%, respectively. In multivariable Cox models, the incidence endpoints were associated with duration of diabetes (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.63-1.89, and HR 2.04, 95% CI 1.73-2.40 per 10 years), moderately low Charlson Comorbidity Index score (HR 1.27, 95% CI 1.10-1.47, and HR 2.80, 95% CI 2.23-3.51), and use of blood pressure lowering medication (HR 1.20, 95% CI 1.05-1.36, and HR 1.98, 95% CI 1.53-2.57). CONCLUSION: In a study of all patients with type 1 diabetes from the Danish DR-screening programme, we identified duration of diabetes, systemic disease and use of anti-hypertensive treatment as consistent risk markers for incident and progressive DR.

Association of continuous subcutaneous insulin therapy and diabetic retinopathy in type 1 diabetes: A national cohort study.

AIM: This study aimed to investigate the short-and long-term effect on diabetic retinopathy (DR) in individuals with type 1 diabetes treated with continuous subcutaneous insulin injections (CSII) compared to those using multiple daily injections (MDI). METHODS: We conducted a register-based matched cohort study utilizing data from the Danish Registry of Diabetic Retinopathy as well as several other national Danish health registers. Our cohort consisted of all individuals with type 1 diabetes who attended the Danish screening program for DR from 2013 to 2022. We included individuals registered with CSII treatment, and compared them to individuals using MDI, matched by age, sex, and DR level. Cox regression analysis was performed to evaluate the outcomes. RESULTS: The study included 674 individuals treated with CSII and 2006 matched MDI users. In our cohort 53.4 % were female and median age was 36 (IQR 27-47). Average follow-up risk-time was 4.8 years. There was no difference in the risk of DR worsening between the CSII group and MDI group (HR 1.05 [95%CI 0.91; 1.22], p = 0.49). However, an increased risk of focal photocoagulation was observed in the CSII group (HR 2.40 [95%CI 1.11; 5.19], p = 0.03). CONCLUSIONS: Our findings indicate that CSII treatment does not confer a significant difference in the overall short- and long-term risk of DR worsening or ocular intervention compared to MDI treatment. These results provide insights into the DR outcomes of CSII treatment in individuals with type 1 diabetes.

Diabetic retinopathy as an independent marker of cardiovascular disease in type 1 diabetes: Results from a nationwide longitudinal matched case-cohort study.

PURPOSE: To investigate diabetic retinopathy (DR) as a potential marker of cardiovascular disease (CVD) in adults with type 1 diabetes attending the Danish DR-screening programme and non-diabetes adults. METHODS: In this registry-based matched case-cohort study, we identified 16 547 adults with type 1 diabetes, who were registered in the Danish Registry of Diabetic Retinopathy (DiaBase). Each case was age- and sex-matched by five non-diabetes individuals (n = 82 399), and odds ratios (ORs) and hazard ratios (HRs) were estimated for incident and upcoming CVD in multivariable models. RESULTS: Adults with type 1 diabetes (median age 44.5 years, 57.6% male) were more likely to have prevalent CVD (OR 1.29; 95% CI, 1.20-1.38) and to develop CVD within 5 years (HR 1.19; 95% CI, 1.08-1.30) as compared to non-diabetes control. However, adults without DR were less likely to develop CVD (HR 0.84; 95% CI, 0.72-0.97) compared to the reference population. For adults with type 1 diabetes, there was an increasing risk for incident CVD for increasing levels of DR (HR 1.33, 1.95, 1.71 and 2.39 for DR-levels 1-4, respectively). Patients with CVD at the time of the first screening had a higher risk to develop DR during follow-up (HR 1.23; 95% CI, 1.02-1.49). CONCLUSION: In a nationwide matched case-cohort study adjusted for potential confounders, DR was identified as an independent marker of prevalent and incident CVD in type 1 diabetes with increasing risk demonstrated for higher levels of DR. Likewise, CVD also independently predicted the risk of incident DR.