The effect of innternal limiting membrane adhesion rate on the results of tractional diabetic macular edema surgery

Internal limiting membrane (ILM) peeling is a technically complex manipulation that is performed during macular surgery. Experts'opinions vary on its necessity. Visual inspection during surgery does not always make it possible to assess the degree of ILM adhesion to the retina. The aimof the study was to evaluate the morphofunctional parameters of the macular zone after ILM peeling with different degree of adhesion in the long-term postoperative period. Material and methods. A study was conducted that included 119 patients with type 1 (65 (55%) and type 2 (54 (45%) diabetes mellitus with proliferative stage of diabetic retinopathy (PDR) and tractional diabetic macular edema (tDME). All patients underwent a standard three-port 25G vitrectomy with the use of an additional endo-luminaire «chandelier» and bimanual membrane peeling technique. During ILM peeling, all patients underwent intraoperative optical coherence tomography (I-OCT) in order to assess the degree of ILM adhesion to the retina. Before, 1 and 12 months after the operation, the determination of the maximum corrected visual acuity (MCVA), OCT of the macular zone with the measurement of the central retinal thickness (CRT) was performed. Results and discussion. 3 degrees of adhesion of ILM to the retina were identified with I-OCT during ILM peeling. The degree of ILM adhesion in fovea significantly correlated with the development of a retinal defect in its central area. The development of retinal central zone atrophy showed a significant correlation with a decrease in MCVA 12 months after surgery and with the degree of ILM adhesion to the retina in patients with both types of DM. Conclusions. According to the results of this study, a significant correlation was shown between the degree of ILM adhesion to the retina determined by I-OCT and the risk of macular atrophy, which in turn is associated with low visual functions of patients after tDME surgery with ILM peeling. The resulting principle can be used in surgery of other vitreomacular interface pathologies. Keywords: vitreomacular interface, epiretinal membrane, diabetic macular edema, tractional diabetic macular edema, intraoperative optical coherence tomography, vitreoretinal surgery, proliferative diabetic retinopathy