Ellipsoid Zone Thickness in Sporadic Adult-Onset Foveomacular Vitelliform Dystrophy

Abstract Purpose: To evaluate the thickness of the ellipsoid zone (EZ) layer and its correlation with visual acuity and the disease stage in eyes with Adult-onset foveomacular vitelliform dystrophy (AFVD).Materials and Methods: Ninety-two eyes of 57 patients with AFVD were evaluated. Four consecutive spectral-domain optical coherence tomography (SD-OCT) scans from each study eye were analyzed. Retinal layers were segmented, and the EZ layer thickness was measure in two areas of the macula: at the center of fovea (CF) and at the foveal avascular zone edge (FE).Results: The mean±SD EZ thickness for was 16.5±9.6 microns at the center of fovea (CF) and 17± 9.8 microns at the edge of foveal avascular zone (FE; p=0.006, t-test). Compared to 30 healthy eyes, the EZ was thicker at the vitelliform stage in both CF and FE (p<0.001 in both points, t-test), and during the pseudohypopyon or vitelliruptive stages in CF (p=0.007, t test), but not in edge of the fovea (p=0.15, t test). Visual acuity was better in eyes with intact EZ compared to absent EZ (p=0.001 for both CF and FE, ANOVA test). There was a trend for an association between EZ thickness and the stage of AFVD (p=0.06, ANOVA test). Conclusion: The foveal EZ thickness in AFVD, is thicker comparing with controls. This might suggest that impaired retinal pigment epithelium phagocytosis or excess photoreceptor EZ production play important role in the pathogenesis of AFVD.