Evaluation of Reticular Pseudodrusen by Polarization-Sensitive Optical Coherence Tomography: case report

Introduction: Reticular pseudodrusen (RPD) are an important clinical biomarker associated with progression to late age-related macular degeneration (AMD). We report polarization-sensitive optical coherence tomography (PS-OCT) findings in a case of RPD and evaluate the entropy characteristics of these lesions. Case Presentation: A 73-year-old man presented for evaluation of retinal angiomatous proliferation in his right eye. The left eye demonstrated multiple round, white–yellowish macular lesions consistent with RPD. Optical coherence tomography (OCT) angiography showed no macular neovascularization in the left eye. Swept-source (SS-)OCT revealed hyperreflective, spike-like deposits between the photoreceptor outer segments (PROS) and the retinal pigment epithelium. Corresponding PS-OCT B-scans demonstrated moderately elevated polarimetric entropy values at the same locations. En face images reconstructed from the PROS layer showed circular RPD-like lesions on SS-OCT, which precisely matched high-entropy areas on PS-OCT. Merged en face maps confirmed one-to-one correspondence between RPD and regions of increased entropy. Conclusion: PS-OCT successfully visualized RPD as moderately high-entropy lesions in the PROS layer, suggesting that these deposits are composed of non-RPE material such as lipids or inflammatory cells. These findings indicate that PS-OCT may serve as a useful complementary modality for detecting RPD and may enhance current imaging strategies for assessing RPD and monitoring AMD progression.