Dynamic Changes of Retinal Microaneurysms in Diabetes Imaged With In Vivo Adaptive Optics Optical Coherence Tomography

PURPOSE. To prospectively monitor microaneurysms (MAs) in three dimensions using adaptive optics optical coherence tomography (AOOCT). METHODS. Patients with diabetes mellitus and parafoveal MAs were included in this longitudinal study. At baseline, MAs were identified in standard fluorescein angiography (FA) and subsequently imaged with an AOOCT prototype, incorporated into an AO fundus camera (RTX1, Imagine Eyes) device. Imaging was repeated every 3 months in each patient to explore the potential structural change of MAs over time including size, shape, intraretinal position, (intra-) luminal reflectivity, and other qualitative morphologic characteristics. RESULTS. We imaged 18 MAs in seven eyes (two left eyes) of five patients (mean age: 69 +/- 7 years) over 18 months. All MAs appeared as saccular in the en face imaging plane at baseline, and no change in shape was observed in any of the MAs during follow-up. Evaluation of the AOOCT volumes revealed dynamic changes of MAs during follow-up including intermittent growth (n = 2), progressive involution (n = 3), total disappearance (n = 2), and MA division (n = 1). Intraluminal hyperreflective material was visualized in 11 out of 18 MAs, which remained stable (n = 3), increased (n = 2), regressed (n = 1), or fluctuated (n = 5). Three MAs without intraluminal spots at baseline progressively developed distinct hyperreflectivities. CONCLUSIONS. AOOCT illustrates the structurally dynamic evolution of MAs in vivo in three dimensions. Despite a consistent saccular shape in the en face view, AOOCT volumes revealed a heterogeneous behavior in regard to size and reflective status of MAs over time.