Individual diabetic retinal lesions were characterized by size, shape, and appearance from the averaged images, and perfusion status was assessed on AOSLO videos viewed in ImageJ (NIH, Bethesda, Maryland).
In the following sections, the main AOSLO characteristics are systematically described.
Small vascular lesions like MA, IRMA, and NV that were sometimes hard to detect or distinguish in IR images or fundus photos could be clearly identified in AOSLO images.
Although HEM could not be differentiated from MA in color fundus photos or IR images, they could be easily distinguished from perfused MAs on AOSLO due to the hemorrhage's lack of blood flow, hyperreflective foci, and/or adjacent feeder vessels.
In confocal AOSLO images, HE appeared as irregularly shaped, grainy-appearing hyperreflective patches with dark borders (Figure 2, Q) casting a shadow on the photoreceptor mosaic.
Cotton wool spots were visible in all imaging modalities applied whereas confocal AOSLO images revealed more details than MSL images.
Though intraretinal cysts could not be identified in confocal AOSLO images, the MSL imaging technique allowed clear delineation of cyst boundaries (Figure 2, N) and wall structures.
This study provides the first detailed, systematic description of multiple vascular and nonvascular retinal lesions of diabetic retinopathy as imaged using noninvasive confocal and multiply scattered light AOSLO technology.
Small lesions of clinical importance, including neovascularization and microaneurysms, were readily detectable on AOSLO even when they were not visualized using SDOCT or standard color fundus photographs.
A major advantage of AOSLO imaging is the ability to visualize intraluminal red blood cell flow in a detailed and dynamic fashion in combination with ultra-high resolution details of blood vessel walls.
The technique of multiply scattered light through decentration of the pinhole aperture, a recently introduced AOSLO imaging method, further enhances image quality of vessel walls and erythrocytes [36, 37].
Hyperreflectivity on AOSLO images was observed in diverse lesion types and may have multiple etiologies.