Clinical Research Directory

Inclusion Criteria: * Voluntary adults * Aged between 18 and 80 years * Understanding of the study explanations and instructions * Prediabetes (defined by elevated fasting glucose 100-125 mg/dL and/or 2-hour glucose in the oral glucose tolerance test of 140-199 mg/dL and/or HbA1c of 5.7-6.4%) * manifest diabetes (all types of diabetes according to Ahlqvist) Exclusion Criteria: * participants unable to give consent * Those who do not agree to be informed about incidentally detected pathological findings * Uncontrolled arterial hypertension (Stage III) despite multiple antihypertensive medications * Eye diseases that impair the interpretability of the fundus examination