Diabetic retinopathy (DR) is a leading complication in patients with diabetes mellitus (DM). Because of the increase in the clinical effectiveness of treatment for diabetes, the life expectancy of patients has increased, which accordingly increases the risk of severe forms of DR (proliferative DR), which is one of the main causes of blindness and low vision in the working-age population. In the literature, the overall prevalence of DR and proliferative DR is up to 34.6% and 12.0%, respectively, whereas 25% of cases of vision loss associated with DR are caused by complications of proliferative DR. Colour fundus photography and optical coherence tomography are the most informative clinical diagnostic methods for DR. In severe stages of proliferative DR, the information content of the presented indicators can be significantly reduced because of insufficient visualisation of the patient’s fundus. Thus, the literature proposes qualitative criteria (specific and single indicators) based on an expert assessment of the condition of the fundus by an ophthalmic surgeon. The described approach has a fairly high diagnostic efficiency. Along with this, it appears relevant to study the ‘quality of life’ of a patient with symptoms of proliferative DR caused by the occurrence of characteristic manifestations of psychological distress (psychological and anxiety disorders and depression). In surgical terms, functional results notably improved after vitrectomy for proliferative DR in 49–83% of cases. Moreover, the proposed methods for conducting vitrectomy for patients with advanced stages of proliferative DR do not fully consider ophthalmological and somatic features, which requires the consideration of the surgical treatment of this contingent as a separate area of vitrectomy for improving ophthalmological ‘techniques’, drug support and choice of anaesthesia.