Correlation of visual function impairment and OCT findings in patients with Stargardt disease and fundus flavimaculatus

PURPOSE. To investigate the relationship between morphologic lesions of the retina and functional abnormalities in patients with Stargardt disease (STGD) and fundus flavimaculatus (FFM). DESIGN. Case-controlled, prospective, comparative observational study. METHODS. A complete ophthalmologic examination, including best-corrected visual acuity (BCVA) and optical coherence tomography (OCT), was performed in 61 eyes of 32 consecutive patients with STGD/FFM and in 60 eyes of 30 matched healthy control subjects. Furthermore, fundus-related perimetry was performed in 12 of the affected eyes. RESULTS. The age ranged from 21 to 71 years in STGD/FFM patients and from 21 to 72 years in controls. BCVA ranged from 20/20 to 20/400 and from 20/20 to 20/32, respectively, in STGD/FFM patients and in controls. A foveal thinning was found by OCT Stratus in almost all cases (average 160 mu m) compared with controls (average 210 mu m) (p< 0.001). BCVA impairment significantly correlated to the degree of foveal thinning (r2= 0.16; p= 0.0014). Moreover, in STGD/FFM patients the authors observed two types of hyperreflective deposits which were not correlated with BCVA impairment or foveal thinning. In addition, fundus-related perimetry revealed a stable fixation in 8/12 eyes, that was predominantly central in only 4 of these eyes. A smaller degree of foveal thinning correlated to a more stable fixation (p= 0.0108), even if not predominantly central (p= 0.0218). CONCLUSIONS. In this series, lower visual acuity and unstable fixation correlated with a greater transverse foveal thinning. OCT and fundus-related perimetry may be useful tools in STGD/FFM patients.