Getting Familiar With EVA

USEFUL FEATURES Twin Duty Cycle EVA’s twin duty cycle (TDC) technology (Figure) provides a high cut rate of 16 000 cpm with a constant open duty cycle of 92%. It significantly reduces the time to complete a core vitrectomy when compared with the Associate (DORC) and other non-TDC machines. A complete core vitrectomy with the 23-gauge system and TDC technology takes an average of 3 to 4 minutes. Given this improvement in efficiency, we have been doing significantly more 27-gauge surgeries with this system. The time to complete a core vitrectomy with the 27-gauge TDC platform comes close to that of a standard 23-gauge procedure with a non-TDC vitrectome. We have found that using 27-gauge instruments requires much less adjustment than initially predicted. As is common with small-gauge surgery, we had an issue with some of the 27-gauge instruments bending, but we resolved the problem with minor adjustments, such as small changes in hand position and the use of a finger on the shaft of the instrument to stabilize it. The limiting factor in converting more cases to 27-gauge is the finite number of options for forceps, scissors, and other instruments for the 27-gauge ports. Although 27-gauge forceps are evolving, they are not quite as good as our current 23and 25-gauge forceps. This is more evident when teaching fellows to peel the ILM and ERM, as they have a harder time learning a new skill with more flexible instrumentation. Our solution has been the use of a hybrid system with two 27-gauge ports for the infusion and the light pipe and one 23-gauge port for the dominant hand (Video 1; eyetube.net/v.asp?f=elude). With the 23-gauge port we are able to use the 27-gauge cutter that comes in the pack to perform the vitrectomy, but we can also peel using our standard 23-gauge instruments. The company has stated that it plans to create hybrid packs to fit this model in the future. This will allow us to open a single pack of trocars, so as not to make the hybrid system cost-prohibitive.