Today diabetes mellitus (DM) is one of the leading medical and social problems. Its complications lead to formidable comorbidities that significantly affect the lives of patients. At the beginning of 2021, there were more than 537 million ¹ people with DM in the world and this number is increasing every year. Diabetic retinopathy (DR) is one of the most severe complications of diabetes affecting the organ of vision. The formation of moorings on the retina, the formation of traction syndrome, hemorrhagic complications, retinal detachment and hemophthalmia, as well as neovascular glaucoma (NG) is a manifestation of the terminal stage of proliferative DR. NG is considered one of the most severe terminal forms of refractory glaucoma, which is steadily progressing, leading to disability and impaired social adaptation [1]. The main method of treating diabetic complications in the posterior segment of the eye is vitrectomy, and in the event of NG, implantation of the Ahmed valve due to the ineffectiveness of conservative therapy. At the same time, one should not forget about multiple complications both during the operation, and in the early and late postoperative periods. To date the pathogenesis of DR development remains unexplored. Apparently, it is based on hyperglycemia, chronic diffuse chorioretinal hypoxia and ischemia of the corresponding structures and tissues. These unfavorable factors trigger a pathogenetic cascade of reactions that cause the release of various angiogenic factors and cytokines. Many researchers have shown the role of the immune response in the development of proliferative DR. This was the reason for the study of the local production of various cytokines and growth factors in patients with DM, proliferative DR and NG. Keywords: diabetes mellitus, diabetic retinopathy, neovascular glaucoma, biomarker, cytokines