deep vitrectomy for diabetic macular edema associated with taut and thickened posterior hyaloid

purpose: to evaluate the effectiveness of pars plana vitrectomy and posterior hyaloid stripping in decreasing macular thickness and improving vision in diabetic macular edema.          methods: this prospective interventional case series includes 30 eyes of 25 diabetic patients with diabetic macular edema with macular thickness exceeding 170 microns and thickened posterior hyaloid. bcva and macular thickness measured by oct were evaluated preoperatively and 4-6 months postoperatively. macular perfusion was evaluated by means of fluorescein angiography preoperatively. treatment consisted of pars plana vitrectomy and stripping of posterior hyaloid. results: mean preoperative macular thickness was 531.97±126.52 mm which decreased to 365.2103.2, postoperatively (p< 0.001). mean preoperative bcva (log mar) was 0.820.39 which improved to 0.650.34 postoperatively (p=0.006). according to pearson correlation coefficient, macular perfusion and presurgical bcva < 20/200 had statistically significant correlation with post surgical bcva. conclusion: pars plana vitrectomy and posterior hyaloid stripping lead to decrease in macular thickness and improvement of vision in patients with diabetic macular edema. all patients are legible to be exposed to the risks of surgery and it is mandatory to select patients for this modality according to macular perfusion state and after documenting the role of vitreous in the pathogenesis of the edema with oct.