High-Resolution OCT of Presumed Basal Laminar Deposit and RPE Abnormalities in Extensive Macular Atrophy with Pseudodrusen-like Appearance.

PURPOSE: To characterize the morphologic spectrum and co-occurrence of basal laminar deposit (BLamD) and abnormal retinal pigment epithelium (RPE) in eyes with extensive macular atrophy with pseudodrusen (EMAP) using High-Resolution optical coherence tomography (OCT). DESIGN: Cross-sectional observational study. PARTICIPANTS: Forty-eight eyes from 25 patients (13 female, 12 male; mean age, 61.7 ± 3.9 years; range, 53-71 years) with EMAP. METHODS: All participants underwent multimodal imaging, including high-resolution spectral-domain OCT, fundus autofluorescence, and swept-source OCT angiography. Morphologic and histologically informed BLamD -like deposits, RPE abnormalities, subretinal drusenoid deposits (SDD) over BLamD, and intraretinal hyperreflective foci (IHRF) were assessed categorically as present or absent. Descriptive statistics were used to summarize overall prevalence and co-occurrence of the various features. MAIN OUTCOME MEASURES: Frequency and distribution of OCT-derived structural features associated with RPE-Bruch's membrane complex alterations and outer retinal atrophy. RESULTS: Persistent BLamD was identified in 39/48 eyes (81.3%), and scalloped BLamD in 31/48 eyes (64.6%). RPE abnormality was present in 21/48 eyes (43.8%), IHRF in 27 eyes (56.3%), and SDD overlying BLamD in 27/48 eyes (56.3%). Eyes with scalloped BLamD numerically more frequent showed RPE abnormalities (67.7% vs. 0%), IHRF (71.0% vs. 29.4%), and SDD over BLamD (74.2% vs. 23.5%) compared to eyes with Persistent BLamD. Eyes with RPE abnormality universally also demonstrated IHRF (100%) and Persistent BLamD (95.2%), suggesting that these features may also be markers of RPE distress. Foveal involvement of atrophy was observed in 48.9% of eyes, with irregular RPE observed in 20.8% of eyes, IHRF in 33.3%, BLamD in 91.7%, scalloped BLamD in 45.8%, and SDD overlying BLamD in 37.5%. CONCLUSIONS: High-Res OCT reveals that BLamD and abnormal/spikey RPE are highly prevalent in EMAP. Distinct BLamD phenotypes can be appreciated in EMAP and scalloped BLamD was frequently associated with RPE abnormality, IHRF, and SDD, suggesting it is associated with features typically interpreted as more advanced local degeneration. Recognition of these phenotypes may enhance structural staging in EMAP.