Management of macular edema in vitrectomized patients with diabetes

Introduction: Diabetic macular edema is the result of a complex interlay of ocular and systemic factors. In diabetic eyes undergoing pars plana vitrectomy surgery (PPV) indications are variable and add to the complexity of the management of persistent or recurring macular edema. Area of research covered: This review focuses on the management of macular edema in eyes of diabetic patients with previous PPV surgery. Additional data are presented for the development of macular edema in relation to non-diabetic etiologies and associated intraoperative factors. The risk/benefit profile of current treatment options was also evaluated. Expert commentary: Vitrectomy plays an important role in the management of vitreoretinal disorders in diabetic patients. Its role in the management of diabetic macular edema (DME) in the absence of vitreous traction remains controversial. There is a paucity of evidence relating to the treatment outcomes for DME in vitrectomized eyes. Pharmakokinetic studies in experimental models have indicated the reduced half-life of anti-VEGF or steroids in vitrectomised eyes though similar studies in humans are lacking. In clinical studies, DME treatment with ranibizumab or bevacizumab has been demonstrated to have favourable visual and anatomic outcomes in vitrectomized eyes in post hoc or retrospective studies. These results are still less favourable in comparison to non vitrectomized eyes. Intravitreal triamcinolone has demonstrated minimal improvement however dexamethasone and fluocinolone implants had encouraging outcomes. For both anti-VEGF agents or steroids well-conducted prospective, randomized controlled trials are needed to substantiate these outcomes.