Prevalence of Diabetic Retinopathy Linked to Duration, Age in Type 1 Diabetes

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A recent cross-sectional study evaluated the prevalence of diabetic retinopathy in patients with type 1 diabetes (T1D) and assessed the associated risk factors for its presence and progression among the population.¹

The descriptive and analytical study of ≥350 patients with T1D revealed that the frequency of retinopathy increased with increasing age, poorer glycemic control, and the duration of disease, particularly for an extent of ≥5 years.

“Systematic diabetic retinopathy screening aims to reduce the risk of vision impairment and blindness because early detection is the key to preserving sight and preventing irreversible retinal damage,” wrote the investigative team, led by Hanane Latrech, the department of Endocrinology-Diabetology and Nutrition, Mohammed VI University Hospital Center.

Considering the rising worldwide incidence of T1D, the number of individuals at risk for developing diabetic retinopathy has also increased, as it is one of the most frequent microvascular complications of diabetes.² Although crucial advances have been made across both medicine and medical technology, clinicians cannot definitively prevent the visual impairment linked to diabetic retinopathy, as its diagnosis and management are often delayed.

Notably, this delay can correspond with the absence of visual impairment symptoms during early disease stages, suggesting the importance of centering screening. The investigative team estimated the prevalence of retinopathy in patients with T1D and evaluated the associated risk factors among the population.¹ The descriptive and analytical study included 359 patients with T1D admitted to the department of endocrinology, diabetology, and nutrition at the investigator’s institution in Morocco.

Interview and physical examination data were collected from medical records, including height, weight, body mass index (BMI), and blood pressure measurements. Glycemic control was determined using data from the daily blood glucose self-monitoring and glycated hemoglobin (HbA1c) assays. Screening and staging of retinopathy were performed during the regular ophthalmological assessments using biomicroscopic examination after dilation, supplemented by fundus photographs.

Among the 359 patients with T1D, the average age was 24.2 years and 50.8% were men. Patients had a mean duration of diabetes of 11.8 years and an average HbA1c at admission of 10.1%. Approximately 30% of patients had diabetic retinopathy, including 28.4% with minimal non-proliferative diabetic retinopathy (NPDR), 19.1% with moderate NPDR, 19.1% with severe NPDR, and 33.3% with proliferative diabetic retinopathy.

Participants with diabetic retinopathy were significantly older than those without retinopathy and often had a higher BMI. Notably, the prevalence of diabetic retinopathy increased significantly with age and longer duration of diabetes. The data showed that 6.2% of people had a duration of <5 years and 79.4% had a duration of >5 years.

Bivariate logistic regression was used to study the independent risk factors that influence the occurrence of diabetic retinopathy. The analysis showed younger age was a protective variable for diabetic retinopathy (adjusted odds ratio [aOR], 0.31; 95% CI, 0.13 - 0.72; P = .006). Meanwhile, the duration of diabetes (P = .02), neuropathy (P = .002), and nephropathy (P = .0001) were each found to be independent risk factors for diabetic retinopathy.

Although younger age was a protective factor against retinopathy, a higher mean HbA1c was associated with the presence of diabetic retinopathy among patients with T1D. These data were in agreement with reports from previous studies, according to Latrech and colleagues.

“Our results emphasize the need for diabetic retinopathy screening during the first year following the diagnosis of type 1 diabetes in patients with very poor metabolic control,” investigators wrote. “On the other hand, we noted that patients whose age is less than 18 years had a lower risk of having diabetic retinopathy, which is underlined in some studies that have labeled age as a risk factor.”

References

1. _{Berrabeh S, Elmehraoui O, Benouda S, Assarrar I, Rouf S, Latrech H. Prevalence and Risk Factors of Retinopathy in Type 1 Diabetes: A Cross-Sectional Study. Cureus. 2023;15(10):e47993. Published 2023 Oct 30. doi:10.7759/cureus.47993}
2. _{World Health Organization: Blindness and visual impairment. [Aug; 2023]. 2023. https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment}