Frequency of Posterior Vitreous Detachment as Determined Intraoperatively in Patients with an Idiopathic Epiretinal Membrane

Introduction: The prevalence of a posterior vitreous detachment in patients with an idiopathic epiretinal membrane is often exaggerated in the literature. This may make the surgeon become overconfident during vitrectomy. Patients and Methods: 34 patients with an idiopathic epiretinal membrane (mean age 72.9 years) were vitrectomised. The membrane and with it the remaining vitreous were stained with Membrane Blue. Results: The preoperative visual acuity was -0.6 +/- 0.176 logMar units. Visual acuity increased postoperatively to -0.3 +/- 0.252 logMar units after 372.6 days. A posterior vitreous detachment was found in 17 patients (50%), whereas there was none in the remaining 50%. There was no correlation between age and prevalence of vitreous detachment. Discussion: The increase in visual acuity was very encouraging. In contrast to reports in the older literature one cannot expect to find a posterior vitreous detachment in patients with an idiopathic epiretinal membrane. This can be checked intraoperatively very easily with Membrane Blue. Such a check becomes more urgent as the posterior vitreous detachment cannot be achieved with 23-G victrectomy as easily as with 20-G vitrectomy.