The typical success rate for a vitrectomy is high, according to WebMD. Most patients see an improvement in their vision. This is especially true of patients who have blood in their vitreous humor that does not resolve on its own.
People who have suffered traction retinal detachment also see the restoration of some of their vision, says WebMD. The results are even more favorable if the detachment hasn't affected their central vision. Vitrectomies are also used to treat large tears in the retina, as well as very bad cases of proliferative retinopathy. This condition can leave scar tissue on the retina.