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

Abstract

Purpose: To evaluate the surgical results of pars plana vitrectomy with peeling of the inner limiting membrane (ILM) in a preliminary series of 12 eyes with diffuse diabetic macular edema.

Patients and methods: Pars plana vitrectomy with peeling of the ILM was performed in 12 eyes with diffuse diabetic macular edema. In 10 eyes, the posterior hyaloid was attached and thickened. Six eyes had undergone macular photocoagulation previously, and two other eyes had been vitrectomized previously. Light and electron microscopy of the specimens obtained during vitrectomy 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 vitrectomized eyes showed a glistening reflex of the vitreoretinal interface but no premacular membrane. The posterior hyaloid and the ILM were removed from the macula. Postoperatively, retinal thickening resolved or decreased in all eyes. Visual acuity improved by at least two lines in 11 eyes. Best-corrected postoperative visual acuity developed within 4 to 12 weeks. No recurrence or deterioration of macular edema or epiretinal membrane formation were observed during the entire period of review (mean, 16 months; range, 8-31 months). Light and electron microscopy showed the presence of the ILM associated with sparse and mostly single-layered fibrous astrocytes.

Conclusion: Vitrectomy including removal of the ILM leads to expedited resolution of diffuse diabetic macular edema and improvement of visual acuity without subsequent epiretinal membrane formation. Complete release of tractional forces and inhibition of reproliferation of fibrous astrocytes seem to be prudent in the eyes of patients with diabetes and advanced vitreoretinal interface disease of the macula.