Correlation of serum endothelin-1 with relapses of surgical treatment of diabetic maculopathy in type 2 diabetes mellitus

Abstract

Introduction. In type 2 diabetes mellitus (T2DM), a cascade of pathological reactions unfolds in the vas­­cular endothelium, which, in turn, is included in the pathogenesis mechanisms and causes the develop­­ment of complications. The main marker of endothelial function is its hormone — endothelin-1 (ET1). The aim of the study was to establish the relation­ship between serum ET1 and relapses in the surgical treatment of diabetic maculopathy (DMP) using various options for vitreoretinal interventions in patients with TD2M. Material and methods. We observed 313 patients T2DM (313 eyes) with DMP and initial (group 1; n = 40), moderate or severe non-proliferative (NPDR; group 2; n = 92) and proliferative diabetic retinopathy (PDR; group 3; n = 181). The severity of retinopathy and DMP was determined in accordance with the recom­men­dations of the American Academy of Ophthalmology (2002). In this study, patients underwent four types of surgical interventions: 78 patients (78 eyes) underwent a three-port closed subtotal vitrectomy; 85 patients (85 eyes) — closed subtotal vitrectomy with peeling of the retina inner border membrane; 81 patients (81 eyes) — closed subtotal vitrectomy with peeling of the retina inner border membrane in combination with panretinal laser coagulation; 69 patients (69 eyes) — closed subtotal vitrectomy with peeling of the retina inner border membrane and panretinal laser coagu­lation in combination with cataract phacoemulsifica­­tion. In pa­­tients before surgery, serum ET1 levels were determined by enzyme-linked immunosorbent assay. The control group consisted of 95 people. For statistical processing of the obtained data, Statistica 10 software (StatSoft, Inc., USA) was used. Results and discussion. In patients with DMP serum ET1 level was many times higher: in group 1 it exceeded the control by 2.9 times, in group 2 — by 3.7 times and in group 3 — by 4.6 times (p < 0.001). The initial ET1 level did not differ with different methods of surgical intervention; there was also no statistical difference between the serum ET1 in each group with different treatment methods (p > 0.5). Serum ET1 level was higher in patients of group 1 with the presence of relapses, compared with patients of the same group who didn’t have relapses (by 1.4 times; p < 0.001). In patients of the remaining groups, there was no such difference (p > 0.2), thus, the level of ET1 was important for the formation of relapses only for patients with initial NPDD. Serum ET1 level was also higher in pa­­tients who had early persistent relapses (p < 0.001), which related to moderate and severe NDPR and PDR. Conclusion. The results showed a correlation bet­­ween the serum level of ET1 and the occurrence of early sustained relapses in the surgical treatment of DMP in patients with T2DM.