High-Resolution Fourier-Domain Optical Coherence Tomography Imaging of Idiopathic Epiretinal Membrane: Correlation Between Visual Function and Morphologic Changes

Abstract

Purpose:: To evaluate the morphologic changes in the macula associated with idiopathic macular epiretinal membrane using high-resolution Fourier-domain optical coherence tomography (Fd-OCT) and correlate these changes with visual function.

Methods:: Ten eyes diagnosed with idiopathic epiretinal membrane were imaged with Stratus OCT and Fd-OCT. Macular function was assessed by ETDRS best corrected visual acuity and microperimetry (Nidek, MP-1). Three-dimensional volumetric images of retinal structures with Fd-OCT allowed registration and correlation of the OCT data with visual functional measurement as determined by microperimetry.

Results:: Best corrected ETDRS visual acuity ranged from 20/20 to 20/50. Fd-OCT images revealed focal irregularities in the photoreceptor outer segment layer and distortions of the inner retinal layers that were not discernible with Stratus OCT. Macular edema was noted in 80% of eyes by Stratus OCT and Fd-OCT, but increased central foveal thickness measurement with both instruments did not always correlate with worse visual acuity. Among eyes with poorer vision, focal irregularities in the photoreceptor layer under the fovea were noted in some eyes, which may contribute to vision loss. Regional loss of sensitivity detected on microperimetry tended to correlate with areas of macular thickening noted on Stratus OCT.

Conclusions:: Fd-OCT allowed detailed visualization of morphologic changes associated with idiopathic epiretinal membrane. Although increased central foveal thickness did not always correlate with poorer visual acuity, regional loss of sensitivity in the macula tended to correlate with areas of macular thickening. Subtle abnormalities in the photoreceptor layer under the fovea were noted in some eyes with Fd-OCT, which may contribute to vision loss.

Keywords: macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • perimetry