In this episode we will cover the basics of trocar placement for vitreoretinal surgery as well as a discussion of considerations for special surgical scenarios. Trocar placement is typically done in 4 steps: 1) Displace the conjunctiva (this will ensure that the sclerotomy is covered by conjunctiva thereby decreasing the risk of infection), 2) Mark the entry location from the limbus (this is done with the back end of the trocar/stiletto system, which has markers that indicate a distance 3mm and 4mm from the limbus), 3) Advance the trocar/stiletto system radial and parallel to the limbus in a beveled fashion approximately 30 degrees from the conjunctival surface, 4) Once a partial thickness, beveled sclerotomy has been created, the trocar is redirected to the mid-vitreous or posterior pole to enter the sclera at the pars plana.
In routine cases, a 3-port pars plana is performed with one trocar in the inferotemporal quadrant (used for the infusion line) and two additional trocars at approximately the 2 o’clock and 10 o’clock positions.
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