In vitro culture Muller cell model to study the role of inverted internal limiting membrane flap technique in macular hole closure.

Inverted internal limiting membrane (ILM) flap may constitute a scaffold for Muller cells whose migration and proliferation on its surface begin the process of macular hole closure. The goal of the study was to establish an in vitro model of the interaction between ILM and the Muller cells. Vitrectomy with inverted ILM flap was performed in 23 patients due to a full-thickness macular hole (FTMH). After dissection of the inverted flap, the area of ILM peeling was extended and material was collected for cell culture experiments. Muller cells cultured on adherent cell plates showed significantly better growth than on suspension plates. Our results reveal that the presence of the ILM can overcome the growth inhibitory effect of the non-adhesive surface. Moreover, the ILM appears to be the optimal growth surface under normoxia conditions mimicking the microenvironment after vitrectomy and hypoxia which is natural state for Muller cells. The closure rate of FTMH was 100%. Our study revealed that in non-adhesive culture conditions patient derived ILM constitutes an optimal growth surface for Muller cells. We have demonstrated that the ILM effectively stimulates attachment, proliferation, and survival of Müller cells in conditions of normoxia which is the case after vitrectomy. The results strongly advocate for the use of inverted ILM flap method in macular hole closure surgeries.