Epiretinal membranes may result from anomalous PVD during vitrectomy, study suggests

The posterior vitreous cortex can split into lamellae during vitrectomy procedures, according to a study by researchers in Japan.

"The finding ... supports the hypothesis that epiretinal membranes are the result of anomalous PVD (posterior vitreous detachment) with vitreoschisis, leaving the outermost layer of posterior vitreous cortex attached to the macula," the authors said in the study.

Akinori Uemura, MD, and colleagues performed vitrectomy on 15 eyes of 15 patients with idiopathic epiretinal membranes. No cases had prior evidence of PVD on slit lamp biomicroscopy and B-scan ultrasonography.

Surgeons injected intravitreal triamcinolone acetonide to create a PVD and observed the relationship between the posterior vitreous cortex and the epiretinal membrane, according to the study.

Investigators found that seven eyes (47%) had a round defect in the posterior vitreous cortex that left an epiretinal membrane on the macula. Complete vitreous cortex and epiretinal membrane detachments were seen in three eyes (20%), the authors reported.

Posterior vitreous cortex detachments without round defects had left an epiretinal membrane on the macula in five eyes (33%). Of these eyes, four had a discrete linear signal over the macular area on optical coherence tomography at baseline, according to the study, published in the March issue of Graefe's Archive for Clinical and Experimental Ophthalmology.