Provided herein are vitrectomy instruments and related systems and methods in which the vitrectomy instruments may include a forward needle stop and a cutter stop to reduce dimensional variation of a cutter of the vitrectomy instruments, allowing for a location of the port formed in a needle of the cutter to be positioned closer to a distal tip of the cutter. With the port located closer to a distal end of the cutter, the port is able to be positioned closer to the retina of an eye.