From the review of the surgical failures that occurred in the last 3 years, it is suggested that a blob of hyaluronic acid resulting from the residual vitreous gel pooled inside the hole is a possible additional reason for failures in the surgery of macular holes. Vitrectomy mainly provides the removal of visible cortical vitreous composed of fibrils of collagen, but a variable amount of viscous hyaluronic acid often collects at the posterior pole at the end of the surgery. In some cases, the fluid\air exchange will pool this viscous material inside the macular hole preventing the migration of glial cells between its borders that takes place in the very first days after surgery. The switch to a mini-invasive small-gauge surgery which through a reduced flow rate compared to the traditional 20 Gauge vitrectomy entails a reduced removal of the liquid component of the vitreous, could be an explanation for the persistence of several otherwise unexplained failures. The introduction of new systems with different duty cycles or an incomplete fluid\air exchange to avoid the intra-operative pooling of the gel inside the hole should be advocated.