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

Purpose

To report the appearance of the fundus, that is seen frequently after removal of an idiopathic epiretinal membrane and which we refer to as the 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 preoperative and postoperative blue filter fundus photographs were reviewed. Histopathologic specimens of epiretinal membranes were available for 14 eyes.

Main outcome measures

The postoperative incidence of the dissociated optic nerve fiber layer appearance on blue filter photographs, visual acuity changes, 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 this feature concerning the average preoperative and postoperative best-corrected visual acuity or the average change in visual acuity. Internal limiting membrane was present in all 14 epiretinal membrane specimens available. Five of these 14 patients concerned exhibited a dissociated optic nerve fiber layer appearance and 9 did not.

Conclusions

The dissociated optic nerve fiber layer appearance occurred frequently after removal of an epiretinal membrane. As far as we know, this feature has not been previously reported. It consisted of numerous arcuate striae within the posterior pole in the direction of the optic nerve fibers and slightly darker than the surrounding retina. This feature had no functional effect noticeable by the patient and did not preclude good visual recovery. The small number of histologic samples and the impossibility of quantifying the area of internal limiting membrane peeled off did not allow us to supply proof that this feature is due to the extensive peeling of the internal limiting membrane, although this is the most likely hypothesis.