AIM:To describe an association between extrafoveal vitreoretinal traction and chronic macular edema,either diffuse (DiME) or cystoid (CME),by the use of optical coherence tomography (OCT).·METHODS:Charts and OCT findings of two patients with persistent DiME or persistent DiME accompanied by CME,both associated with extrafoveal vitreous traction membranes were analyzed. Excluded were eyes that either had another vitreoretinopathy that could affect the analysis,had undergone pars plana vitrectomy or that had been treated by intravitreal medications. An age-matched normal control group for OCT (n=12) allowed for the quantification of the normal macular thicknesses.·RESULTS:One patient (one eye) following perforating ocular injury and one patient (one eye) of idiopathic origin,both with chronic macular edema refractive to conventional treatment,were found to be associated with extrafoveal vitreoretinal traction in each eye. Retinal edema that was underlying the traction site in each eye was in continuum with the central macular edema,thus manifesting as diffuse macular edema. The automatic central 6-radial lines program in the OCT enabled the detection of the traction site in one eye,while in the other eye the diagnosis was achieved only with the additional use of the Line group program. ·CONCLUSION:Chronic diffuse macular edema might be related to extrafoveal vitreoretinal traction. Careful search with the diverse OCT programs should be made in order to detect extrafoveal traction sites. Further studies and a larger cohort are required to compare the efficacy of early vitrectomy or pharmacologic vitreolysis versus the current therapeutic approaches in these situations.