Background The clinical phenotype of Stargardt disease (STGD) can be extremely heterogeneous, with variable macular and peripheral retinal involvement. The study aim was to correlate peripheral ultrawide field (UWF) involvement with macular alterations, as assessed by structural optical coherence tomography (OCT) and OCT angiography (OCTA), in order to identify potentially different phenotypes.

Methods The study involved patients with STGD and healthy controls. We performed a complete ophthalmologic assessment and multimodal imaging, including OCT, OCTA, fundus autofluorescence and UWF imaging. Patients with STGD were subdivided according to the peripheral involvement. OCT and OCTA quantitative parameters were analysed. The main outcome of the study was the classification of UWF subtypes and the correlation between UWF subtypes and macular involvement.

Results Seventy STGD eyes (19 male; mean age 41.3±13.2 years) and 70 healthy eyes (35 male; 50%; mean age 41.2±9.8 years) were included in the analyses. Mean best-corrected visual acuity was 0.60±0.45 LogMAR for the STGD group and 0.0±0.0 LogMAR for controls (p<0.01). All clinical and imaging findings proved to be statistically worse in patients with STGD than in the control subjects (p<0.01). UWF types were distributed as follows: type I (49%), type II (34%), type III (17%). Type III patients proved to be significantly worse in terms of visual function and OCT and OCTA imaging parameters.

Conclusions The UWF autofluorescence performed in the present study suggests that there exist three different STGD phenotypes. Each phenotype is associated with variable OCT and OCTA impairment. Further studies providing a better assessment of the peripheral retinal involvement in STGD are warranted.