Pars plana vitrectomy. Removal of preretinal membranes.

Removal of preretinal membranes in pars plana vitrectomy is achieved with the two-instrument technique by using a hooked needle or vitreous scissors, in addition to the vitrectomy instrument. Preretinal membranes are found in proliferative diabetic retinopathy, perforating injuries, and in retinal detachments with massive periretinal proliferation. Technique and results have been described in the text.