Fluidics and cutter dynamics.

An understanding of the physics and engineering principles underlying vitrectomy fluidics and cutter function is essential as we seek to improve outcomes by reducing iatrogenic retinal breaks and facilitate removal of all traction. One of the many challenges facing the vitreoretinal community working in collaboration with engineers developing new systems is the difficulty in moving forward from obsolete, less effective, and potentially higher-risk techniques and parameters. The notion that 20-gauge vitrectomy is the 'gold standard' and should be used for difficult cases is simply wrong. Similarly, the idea that huge flow rates are 'efficient' and beneficial when in fact they cause excessive vitreoretinal traction is a significant issue. The obsolete notion of combining vitrectomy with scleral buckling must be eradicated; patients do not want pain, long procedures, refractive error, or strabismus; vit-buckle outcomes are not better than vitrectomy alone.