Diabetic retinopathy (DR) is a well-known and the most common microvascular complication of diabetes. It's characterised by neurovascular changes in the retina due to retinal hyperglycaemia and following hypoxia.1 The progression of DR eventually causes neovascularization and alterations in vascular permeability in the retina, leading to evolution of proliferative diabetic retinopathy (PDR) and diabetic macular oedema (DME), respectively. Severe visual loss and visual impairment may occur if DR is not treated in a timely manner.2 The asymptomatic nature of DR in its every stage emphasises the need for timely diagnosis and treatment. From these bases rises the need for well-organised DR screening and a follow-up system to prevent new-onset blindness.3., 4. The common risk factors for DR include hyperglycemia, dyslipidemia, hypertension, and long duration of diabetes.5., 6. The patients suffering from type 1 diabetes since early childhood are particularly at risk for developing DR due to onset of puberty after diagnosis and long disease duration already at young adult age.7., 8. Our recent study has revealed that 35 % of all patients diagnosed with type 1 diabetes at childhood had developed PDR after 23 years of disease duration.9

Panretinal photocoagulation (PRP) has been considered as the gold standard in PDR treatment for decades since it was proven effective in the 1970's.10 However, despite the improvements in the laser devices and technology, visual field loss and decreases in colour vision and contrast sensitivity have been reported after PRP, given the invasive nature of the treatment.11 Several recent studies have suggested that intravitreal anti-VEGF agents might provide an effective alternative approach in PDR due to better visual outcomes and less defects in visual field.12., 13., 14., 15., 16. Most patients with type 1 diabetes and DR have useful vision, although variable functional impairments may occur.17 Long duration of type 1 diabetes in association with non-optimal glycaemic control may threaten visual function already at young adulthood leading to a possible negative impact on the quality of life. The present study aims to evaluate the effect of PDR and long-term duration of diabetes for 35 years on comprehensive visual function in patients with type 1 diabetes since childhood. In addition, the stability of DR, balance of diabetes, and measurements of Health-Related Quality of Life (HRQoL) are compared to the results of prior follow-up examination of the same cohort in 2007.18