The role of prognostic biomarkers in the treatment and assessment of the risk of complications of diabetic retinopathy

Relevance The number of people suffering from diabetes mellitus (DM) and diabetic retinopathy is increasing in Russia. Prognostic biomarkers are more often used in practice, but often do not allow making a complete prognosis. Objective To describe complex prognostic biomarkers of diabetic retinopathy in clinical cases with a prolonged (up to 3 years) observation period, to study their impact on treatment and assessment of the risk of complications of this disease. Material and methods The article presents clinical observations of five patients (7 eyes) with type 1 and 2 DM and proliferative diabetic retinopathy (PDR) who underwent vitreoretinal surgery for complications of PDR [1–4]. The patients were aged from 25 to 60 years inclusive, including 3 men and 4 women, the duration of diabetes was at least 10 years. The patients were examined before treatment and during periodic examinations at 1; 3; 6; 12; 24 and 36 months after treatment. The examination included a standard ophthalmological examination and OCT of the central sections. Complex biomarker (CB) is a combination of changes and symptoms obtained from the results of various methods of patient examination. The study presents two types of CB. The first is called PIRATES. Changes included in PIRATES reflect a completed episode of focal ischemia with an outcome in partial retinal atrophy, they minimize the likelihood of production of proangiogenic factors by the tissues of the specified zone. Thus, PIRATES can be associated with a more favorable prognosis for the risk of complications associated with proliferation and increased concentration of vascular endothelial growth factor - VEGF. The second CB is called "terminal syndrome". Changes reflect a pronounced proangiogenic potential with a high risk of retinal venous occlusion, the formation of ischemic zones and increased VEGF production. Thus, the presence of terminal syndrome may be prognostically unfavorable in terms of the risk of complications associated with proliferation and increased VEGF concentration. Results Patients 1–5 showed signs of PIRATES, while patients 6 and 7 showed terminal syndrome. At all observation periods, patients with PIRATES showed high stability of visual functions, no significant structural changes, and complications. Patient 6 showed signs of retinal venous occlusion in the area of ​​the distal branches of the temporal veins and rubeosis of the iris at a 3-month observation period and patient 7 showed signs of retinal venous occlusion in the area of ​​the distal branches of the temporal veins and rubeosis of the iris at a 6-month observation period, which confirms the hypothesis of the proangiogenic potential of changes in terminal syndrome. Conclusion CBs can be used to predict treatment outcomes and the risk of complications, but they require further study with a larger number of observations. Key words: diabetes mellitus; diabetic retinopathy; biomarker