Dissociated optic nerve fiber layer appearance of the fundus after idiopathic epiretinal membrane removal

Purpose: To report the appearance of the fundus, that is seen frequently af ter removal of an idiopathic epiretinal membrane and which we refer to as t he dissociated optic nerve fiber layer appearance. Design: Interventional, noncomparative retrospective case series. Participants: One hundred consecutive patients with an epiretinal membrane who underwent pars plana vitrectomy and epiretinal membrane peeling in one eye. Methods: Only patients with an idiopathic epiretinal membrane or a membrane associated with a peripheral retinal tear, but without retinal detachment, were considered for this study. Sixty-one patients met these criteria for one eye. Preoperative and postoperative best-corrected visual acuity and pr eoperative and postoperative blue filter fundus photographs were reviewed. Histopathologic specimens of epiretinal membranes were available for 14 eye s. (C) 2001 by the American Academy of Ophthalmology. Main Outcome Measures: The postoperative incidence of the dissociated optic nerve fiber layer appearance on blue filter photographs, visual acuity cha nges, and the presence of internal limiting membrane in epiretinal membrane specimens. Results: The postoperative incidence of this feature on blue filter fundus photographs was 43%. No difference was found between eyes with or without t his feature concerning the average preoperative and postoperative best-corr ected visual acuity or the average change in visual acuity. Internal limiti ng membrane was present in all 14 epiretinal membrane specimens available. Five of these 14 patients concerned exhibited a dissociated optic nerve fib er layer appearance and 9 did not. Conclusions: The dissociated optic nerve fiber layer appearance occurred fr equently after removal of an epiretinal membrane. As far as we know, this f eature has not been previously reported. It consisted of numerous arcuate s triae within the posterior pole in the direction of the optic nerve fibers and slightly darker than the surrounding retina. This feature had no functi onal effect noticeable by the patient and did not preclude good visual reco very. The small number of histologic samples and the impossibility of quant ifying the area of internal limiting membrane peeled off did not allow us t o supply proof that this feature is due to the extensive peeling of the int ernal limiting membrane, although this is the most likely hypothesis.