En face spectral-domain optical coherence tomography for the monitoring of lesion area progression in stargardt disease

PURPOSE. We investigated the progression of Stargardt disease (STGD1) over a multiyear follow-up by evaluating the macular lesion area as computed by an automatic algorithm from spectral-domain optical coherence tomography (SD-OCT). METHODS. We reviewed medical records of STGD1 patients, with a clinical and molecular diagnosis of STGD1 at a single institution, who underwent best-corrected visual acuity (BCVA), fundus photography, SD-OCT, full-field electroretinography, and, when available, fundus autofluorescence (FAF). Regression models were fitted on the selected clinical parameters; in particular, on the macular lesion area computed by SD-OCT, to evaluate the disease progression over a multiyear follow-up. RESULTS. The comparison between SD-OCT and FAF, available for 22 patients, showed that macular lesion area, assessed by SD-OCT, significantly correlated with the area of absent FAF (P < 0.001). Moreover, the longitudinal analysis, performed in 98 patients, showed a significant enlargement of macular lesion area at an estimated exponential rate of 4.6% per year (P = 0.046), together with a significant worsening of BCVA (0.06 logMAR per year; P < 0.001) and a significant decrease of macular thickness (1.6% per year; P = 0.005) over the follow-up. CONCLUSIONS. The current study describes, for the first time in literature, a longitudinal analysis of the macular lesion area assessed by SD-OCT in STGD1 disease, showing a significant progression over the follow-up. Our findings suggest that the evaluation of macular lesion area by en face SD-OCT, together with FAF, could drive the choice of the most amenable candidates and the most suitable area to be treated in gene therapy clinical trials.