Resolution of diabetic macular edema after surgical removal of the posterior hyaloid and the inner limiting membrane

Purpose: To evaluate the surgical results of pars plana vitrectomy with pee ling of the inner limiting membrane (ILM) in a preliminary series of 12 eye s with diffuse diabetic macular edema. Patients and Methods: Pars plana vitrectomy with peeling of the ILM was per formed in 12 eyes with diffuse diabetic macular edema. In 10 eyes, the post erior hyaloid was attached and thickened. Six eyes had undergone macular ph otocoagulation previously, and two other eyes had been vitrectomized previo usly. Light and electron microscopy of the specimens obtained during vitrec tomy was performed. Visual acuity and retinal thickening were monitored, Results: Intraoperatively, the posterior hyaloid was found to be thickened and completely attached to the macula in 10 eyes, Two previously vitrectomi zed eyes showed a glistening reflex of the vitreoretinal interface but no p remacular membrane, The posterior hyaloid and the ILM were removed from the macula, Postoperatively, retinal thickening resolved or decreased in all e yes. Visual acuity improved by at least two lines in 11 eyes, Best-correcte d postoperative visual acuity developed within 4 to 12 weeks. No recurrence or deterioration of macular edema or epiretinal membrane formation were ob served during the entire period of review (mean, 16 months; range, 8-31 mon ths), Light and electron microscopy showed the presence of the ILM associat ed with sparse and mostly single-layered fibrous astrocytes. Conclusion: Vitrectomy including removal of the ILM leads to expedited reso lution of diffuse diabetic macular edema and improvement of visual acuity w ithout subsequent epiretinal membrane formation, Complete release of tracti onal forces and inhibition of reproliferation of fibrous astrocytes seem to be prudent in the eyes of patients with diabetes and advanced vitreoretina l interface disease of the macula.