Long-term results of changes in retinal thickness after surgical treatment of patients with resistant diabetic macular edema

Relevance In the modern world, diabetic retinopathy (DR), complicated by diabetic macular edema (DME), can contribute to irreversible vision loss in patients and requires timely treatment [1]. Angiogenesis inhibitors are currently the "gold standard" for DME therapy, including resistant DME [2]. In the absence of positive dynamics on anti-VEGF drugs, implants with glucocorticosteroids can be used [3]. A number of authors note in their works that vitrectomy with peeling of the internal limiting membrane (ILM) can be pathogenetically justified in the early stages of diabetic retinopathy [4]. Objective To analyze the dynamics of changes in retinal thickness after surgical treatment of patients with resistant diabetic macular edema. Material and methods We examined 24 patients (24 eyes) diagnosed with resistant diabetic macular edema, who had previously received injections of anti-VEGF drugs without positive dynamics. Vitreoretinal surgery had not been performed on the patients before. In the 1st group, 12 patients (12 eyes) continued therapy with antivasoproliferative drugs (Aflibercept, Brolucizumab). In the 2nd group (12 patients, 12 eyes), standard three-port 25G vitrectomy, membrane peeling with removal of the ILM and endotamponade with a C2F6 gas-air mixture were performed. All patients underwent optical coherence tomography (OCT) before surgery, after 1 week, 1, 6 and 12 months, which determined the central retinal thickness in the Full Retinal mode. Results Surgical interventions in both groups were performed without intra- and postoperative complications. After 1.6 months, patients in group 2 showed a statistically significant decrease in the retinal thickness in the fovea with similar parameters as in patients in group 1. At 1 year after surgery, a tendency toward an increase in the thickness of the retinal tissue in the fovea was noted; no statistically significant changes were found. The data are shown in the table. Conclusion According to literature data, when performing vitreoretinal surgery with membrane peeling, patients experience an improvement in morphofunctional parameters, and the risk of recurrent edema also decreases [5]. In the group using vitreoretinal surgery, it was found that the rate of edema resorption occurs faster at 1.6 months. Thus, vitrectomy with membrane peeling can be one of the treatment options for patients with resistant diabetic macular edema. To confirm the reliability of the results, a study on a larger sample of patients is necessary. Key words: diabetic retinopathy; diabetic macular edema; membrane peeling; optical coherence tomography