LAUSR

PURPOSE To assess ellipsoid zone (EZ) alterations in Best vitelliform macular dystrophy (BVMD) using spectral-domain optical coherence tomography (SD-OCT). METHODS Prospective, observational case series. Forty-three patients (43 eyes) underwent complete ophthalmological examination at baseline and at 24 months: best-corrected visual acuity (BCVA), biomicroscopy, fundus photography, SD-OCT. Acquisition protocol included 19-line raster scan. EZ alterations were marked on SD-OCT and the area was manually calculated on a near-infrared reflectance image. Three patterns were identified: A (decrease >0.25 mm), B (±0.25 mm), C (increase >0.25 mm). Primary outcome was to describe different patterns of EZ alteration. Secondary outcomes included their correlation with BCVA and the description of a central optically-preserved islet (OPI). RESULTS At baseline, altered EZ was identified in 40 eyes. Worse BCVA significantly correlated with larger EZ alterations, but not with lesion extension on fundus photograph. Only 'pattern-C' eyes unveiled BCVA worsening at follow-up. OPI was detected in 16 eyes (37%), disclosing significantly better vision; its disappearance at follow-up (n=7; 44% of 16 eyes) correlated with a drop in BCVA. CONCLUSIONS The assessment of EZ status might represent a valuable functional marker in BVMD, as stable alterations and the maintenance of a central OPI are associated with better visual acuity.