During vitrectomy through the pars plana, a second instrument, introduced through the opposite pars plana, is useful for specific surgical situations. Removal of pooled blood is facilitated by insertion of a 22-gauge needle connected to an additional infusion bottle. Large bleeding vessels are diathermized with a straight diathermy needle. Preretinal membranes are peeled off with a modified 22-gauge hypodermic needle. Solid vitreous strands are cut with a vitreous scissors, and foreign bodies are removed with a foreign-body forceps. Fiberoptics provide optimal illumination inside the eye for these manipulations.
Machemer R. A New Concept for Vitreous Surgery7. Two Instrument Techniques in Pars Plana Vitrectomy. Arch Ophthalmol. 1974;92(5):407-412. doi:10.1001/archopht.1974.01010010419009