[Retro mode imaging and early-stage AMD]

Age-related macular degeneration (AMD) is a chronic disease whose progression toward advanced stages is closely related to the phenotype observed at the early and intermediate stages. The detection and characterization of drusen and pigmentary abnormalities are central to the stratification of progression risk. Retro mode imaging, based on indirect infrared retro-illumination, enhances the visualization of retinal surface elevation, depth-related features, and variations in pigment density. This review examines the contribution of the various retro mode configurations (deviated left [DL]; deviated right [DR]; and ring aperture [RA]) in AMD, based on recent data in the literature as well as our clinical experience. When integrated into a multimodal imaging strategy, the combined use of DL and DR modes improves the detection and morphological assessment of drusen, while the ring aperture mode facilitates the identification of subtle pigment migration at the onset of the disease. A more precise characterization of these lesions allows refinement of AMD staging and provides clinically meaningful prognostic information.