Three-Year Longitudinal Follow-Up of an RPE Tear Using PS-OCT Polarimetric Entropy: A Case Report

Purpose: To report a 3-year ROI-based longitudinal follow-up of an nAMD-associated retinal pigment epithelium (RPE) tear using polarization-sensitive optical coherence tomography (PS-OCT)–derived polarimetric entropy (PE), with concurrent MP-3 microperimetry. Methods: A 75-year-old woman with an nAMD-related RPE tear was followed for 3 years. At baseline and follow-up visits, decimal best-corrected visual acuity (BCVA), structural OCT findings, en-face PE at the RPE level, and MP-3 retinal sensitivity were recorded. Two fixed regions of interest (ROIs; RPE tear ROI and RPE tear flap ROI) were defined at baseline and propagated across visits using image registration. Mean PE and mean MP-3 sensitivity (dB) were calculated within each ROI. Results: BCVA improved from 0.3 at baseline to 0.9 at 6 months and 1.0 at 1 year, then declined to 0.7 at 2 years and 0.6 at 3 years, when subretinal fluid (SRF) was present (anti-VEGF administered as needed). From baseline to 6 months, PE increased in both ROIs (RPE tear ROI: 0.085→0.193; RPE tear flap ROI: 0.413→0.543), and MP-3 sensitivity also increased (RPE tear ROI: 10.1→22.0 dB; RPE tear flap ROI: 14.0→19.7 dB). At 1 year, PE was 0.180/0.347 and MP-3 sensitivity was 22.2/17.2 dB in the RPE tear/RPE tear flap ROIs, respectively (BCVA 1.0). At the later SRF-positive visits, PE values were 0.182/0.350 at 2 years and 0.249/0.362 at 3 years, whereas MP-3 sensitivity decreased to 18.8/13.9 dB and 11.9/9.2 dB, respectively. Conclusion: PE increased during early follow-up and subsequently showed region-specific longitudinal changes within the RPE tear and RPE tear flap ROIs, while MP-3 sensitivity decreased at later visits associated with recurrent exudation. These findings suggest that PE may provide longitudinal structural information regarding RPE remodeling, with microperimetry providing complementary functional context.