Fig. 6From: Vitreoretinal instruments: vitrectomy cutters, endoillumination and wide-angle viewing systemsDual pneumatic vitrectomy cutter. An air pulse pushes down the diaphragm located inside the vitrectomy probe, leading the port to a closed position (the guillotine movement); another air pulse, in a separate air line, pushes the diaphragm back to the port open position. Image courtesy of Alcon (Ultravit® probe—Alcon, USA)Back to article page