Inclusion Criteria:  Highly myopic patients (axial length > 26mm) with vitreoretinal diseases or maculopathy requiring pars plana vitrectomy  Exclusion Criteria:  Previous history of pars plana vitrectomy Surgical plan combining encircling buckle Silicone oil or perfluorocarbon liquid use intraoperatively Previous history of pterygium surgery, trabeculectomy, glaucoma surgery Previous history of corneal, conjunctival, or scleral laceration History of connective tissue disease