A vitrectomy procedure removes the vitreous humor or gel-like substance in the eye. This approach can address vision problems caused when foreign matter invades the vitreous cavity of the eye. One example of foreign matter is blood, from conditions such as diabetic vitreous hemorrhage. Light rays passing through the eye cause the foreign matter to cast shadows on the retina, resulting in distorted or significantly reduced vision. A pars plana Vitrectomy removes the clear, gel-like substance from your eye’s interior. Once the surgeon removes the vitreous humor and clears the area, he or she usually injects a saline, gas or special oily liquid to replace the vitreous humor that ordinarily fills up the inner chambers of the eye.