Discussion
vitreoretinal interface disorders, inflammation, MHs, PVD
INFLAMMATION, OPTIC NERVE, PROLIFERATIVE VITREORETINOPATHY, RETINAL DETACHMENTS, PVD
The creation of a PVD is critical in PPV for most macular vitreoretinal interface disorders and retinal detachments. However, PVD induction can be a challenging surgical step in young patients and in older patients with a particularly adherent posterior hyaloid or abnormal vitreoretinal interface. Failure to successfully induce PVD can result in poor surgical outcomes, such as persistent MHs and proliferative vitreoretinopathy.As highlighted by Takeuchi et al. [Otani et al. [Although different methods have been described, most surgeons tend to use active suction of the vitreous to cause the PVD, making different attempts around the optic nerve and switching to other methods when this method is insufficient. The PVD induction depends on the capability to engage the vitrectome probe with the posterior hyaloid and is directly proportional to the flow rate of the vitrectomy machine. The evolution of probe design continues to expand the variety of surgical parameters governing the flow rate. Design improvements such as reduced outer probe diameter have led to 23- and 25-gauge transconjunctival sutureless vitrectomy instruments that reduce sclerotomy inflammation [Poiseuille's law can be used to describe the flow rate through a vitrectomy probe, and the variable R represents the thinner lumen radius. However, Poiseuille's equation is valid for laminar flow of an incompressible fluid, and the heterogeneous composition of vitreous complicates the fluid dynamics during vitrectomy. Nevertheless, we can hypothesize that engaging the posterior hyaloid with the vitreous probe is strongly related to the vitrectome diameter, which influences the flow rate. This is why increasing the coupling between the hyaloid and vitrectome with a movement of the probe could result in safer and faster PVD.