Why are Reticular pseudodrusen (RPD) well visualized on FAF, IR, and OCT?

Reticular pseudodrusen (RPD) are best visualized on fundus autofluorescence (FAF), infrared (IR) imaging, and optical coherence tomography (OCT) primarily because they are situated above the retinal pigment epithelium (RPE). This specific location allows for enhanced visualization on these imaging modalities.

On FAF, the accumulation of cellular material and fluid above the RPE appears as hyperautofluorescent areas, making RPD distinctly visible. In IR imaging, which captures the reflectance from the retina, RPD can also be recognized due to their distinctive pattern and placement. Furthermore, OCT provides cross-sectional imaging of the retina, revealing the structural relationship of RPD with the surrounding retinal layers, as they present as a pattern above the RPE, demonstrating the characteristic reticular pattern that helps in differentiation from other forms of drusen.

Understanding the spatial relationship of RPD relative to the layers of the retina is crucial in interpreting these imaging results effectively. This highlights the importance of their location in diagnostic imaging and the ability to identify and differentiate various retinal pathologies.