Screening for diabetic retinopathy with fluorescein angiography in patients with type 1 diabetes from adolescence to adult life. A retrospective study of the past 30 years of clinical practice in a tertiary Belgian centre.

Background: The aim of the present study was to describe the prevalence and progression of DR diagnosed by fluorescein angiography (FA) in patients with type 1 diabetes (T1D) during a 30-year follow-up, and the relationship with glycated haemoglobin (HbA1c).

Materials And Methods: We included 4325 FA reports representing 851 patients with T1D with a mean age at diagnosis of 10.4 years (range: 0.0-49.9) and followed between 1986 and 2015. Clinical characteristics of the population were collected from patients' files. The HbA1c level was measured within a maximum period of ±1 year from the date of FA. Descriptive statistics were realized to study prevalence and progression of DR.

Results: At diagnosis of incipient abnormalities, mean age was 22.8 years (range 13.7-46.9) and mean diabetes duration was 13 years (range: 4.3-29.6). Lesions requiring treatment were observed in 5.9% of the patients at a mean age of 32.4 years (range: 30.4-34.3) and a mean diabetes duration of 23.8 years (range: 19.4-28.1). On average, it took 12.9 years (range: 12.2-13.5) to progress from an incipient abnormality to a lesion requiring treatment. Mean HbA1c ± SD was 7.8 ± 1.5% over a period of 30 years.

Conclusions: While it could have been expected to observe a higher prevalence of DR, our study described by far the lowest results of prevalence comparing to similar studies, probably due to a good average HbA1c over 30 years.