Induction of a posterior vitreous detachment (PVD) is a critical step in successful vitrectomy procedures. In some cases the PVD may already be present but in other cases, induction of the PVD is necessary to ensure adequate removal of vitreous and prevention of vitreous contraction that may cause a retinal detachment. In this video a vitreoretinal fellow demonstrates the key steps to PVD induction including: 1. Starting the PVD induction over or at the edge of the optic nerve, 2. Maximally aspirating the vitreous with the cutter off, 3. Moving the cutter away from the optic nerve and along the surface of the retina, and 4. Lifting up the vitreous away from the retinal surface. Two cases are presented. The first demonstrates the importance of moving the cutter in the same direction as the cutter mouth so as to maintain good purchase of the vitreous during PVD induction. The second case demonstrates PVD induction when the retina is detached. In this scenario the elevation of the PVD should first be done away from the detached retina. If vitreous is still adherent to areas of detached retina, the vitreous can be elevated in such a way that the cutter mouth is moving vertically or away from the detached retina to avoid retinal incarceration and potentially an iatrogenic retinal break.
