Morpho-functional correlation of fundus autofluorescence in Stargardt disease

To correlate patterns in short-wavelength (SW) and near-infrared (NIR) fundus autofluorescence (FAF) with morpho-functional outcomes in eyes affected by Stargardt disease.

Fifty-four eyes of 27 patients were prospectively enrolled. All patients underwent a complete ophthalmologic examination including SW-FAF, NIR-FAF, microperimetry and spectral-domain optical coherence tomography (SD-OCT). The main outcome measures were identification of a correlation between NIR-FAF and SW-FAF patterns within the foveal region and best corrected visual acuity (BCVA) values. Secondary outcome measures were correlation of FAF patterns with SD-OCT findings and retinal sensitivity on microperimetry.

Eyes showing a pattern of foveal hyper-FAF on NIR-FAF had a higher BCVA than eyes with a reduced FAF signal (0.44±0.23 LogMAR vs 1.08±0.19, p<0.001). Similarly, mean sensitivity within 2° of the foveal region was significantly better (6.45±2.39 dB) in eyes with hyper-FAF than in eyes with hypo-FAF (0.23±0.45 dB, p<0.001). Moreover, eyes with hyper-FAF on SW-FAF did not present a significant difference in BCVA (0.73±0.31 vs 0.83±0.43, p=0.335) and mean retinal sensitivity (4.34±3.91 dB vs 2.33±2.96, p=0.07) compared with the subgroup with foveal hypo-FAF. The integrity of both the photoreceptor inner/outer segment junction and the photoreceptor outer segment/retinal pigmented epithelium junction was significantly correlated with a preserved BCVA and a foveal hyper-FAF pattern on NIR-FAF.

Our data suggest that NIR-FAF patterns correlate with morpho-functional outcomes in eyes affected by Stargardt disease. Longitudinal investigations are warranted to assess more precisely the actual contribution of NIR-FAF in the clinical characterisation of Stargardt disease.