Hyperreflective foci in Stargardt disease: 1-year follow-up

Purpose: To describe the hyperreflective foci (HF) characteristics in eyes affected by Stargardt disease (STGD), correlating HF with the atrophy progression at 1-year follow-up. Methods: Prospective observational case series with 1-year follow-up. Twenty-eight eyes (14 patients) affected by STGD and 28 eyes (14 age- and sex-matched healthy patients) used as control group were recruited. All patients underwent a complete ophthalmologic examination including fundus autofluorescence and spectral-domain optical coherence tomography. The primary outcome was the identification of HF specific location in STGD and their modification over a 1-year follow-up. Secondary outcome included the correlation between the number and the location of HF and atrophic changes. Results: HF turned out to be more frequent in STGD patients compared with healthy controls (p < 0.001). In particular, mean number of HF in the pathological edge was significantly higher than in the healthy edge of the atrophy (p < 0.001) and in the foveal area (p < 0.001). A negative correlation was found between the total HF number in the pathological edge and the atrophic area at baseline. HF number in the outer retina of the pathological edge significantly decreased between the baseline and the final follow-up examination (p = 0.011). The enlargement of the atrophic area in eyes with more than five outer retinal HF in the pathological edge at baseline was significantly less than that found in the eyes with fewer than five HF (p = 0.010). Conclusions: HF are most common at the pathological margin of the central atrophy, with outer retina foci being more frequently found in smaller atrophic lesions.