BackgroundRetinal arterial macroaneurysm (RAM) is a common clinical disease leading to vision loss in elderly individuals. The appropriate interpretation of swept-source optical coherence tomographic angiography (SS-OCTA), a noninvasive examination, is easy and convenient for detecting the status of RAMs and guiding treatment.MethodsThe objectives of this study were to describe the morphologic characteristics of RAMs using SS-OCTA and to observe whether there are differences in the morphologies of RAMs between SS-OCTA and fundus fluorescein angiography (FFA), before and after treatment. We retrospectively evaluated twenty-two eyes of 22 patients who were diagnosed with RAMs. All patients underwent a complete ophthalmologic examination, including a review of medical records, best-corrected visual acuity (BCVA), fundus photography, FFA and SS-OCTA. RAMs were recorded by SS-OCTA before any treatment or observation decisions were made. The morphologic findings of the RAMs on SS-OCTA were investigated.ResultsOn SS-OCTA, RAMs can show local dilatation or an irregular linear blood flow signal, and the dilated cystic lumen may show thrombosis with a low reflection signal. After treatment, the shape of the RAMs will show reactive changes. The findings on SS-OCTA are not very consistent with those on FFA.ConclusionsThe same RAM may have different manifestations on OCTA and FFA, and OCTA can more conveniently reflect the changes in blood flow signals and treatment response of RAMs.