This study aimed to compare the safety and efficacy of vitrectomy probe with different shaft lengths in vitreoretinal surgery of highly myopic patients. In this randomized controlled study, highly myopic patients who had axial length more than 26 mm and needed vitreoretinal surgery will be enrolled. The enrolled patients will be randomized into "30 mm shaft length group"(trial group) and "27mm shaft length group"(controlled group). We will compare the rate of wound leakage, hypotony, subconjunctival hemorrhage, probe bending, trocar removal, and endophthalmitis between the two groups. We would like to evaluate the efficacy and safety of the 30 mm shaft length vitrectomy probe.

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