Enhanced Visualization of Choroidal Defects in Focal Choroidal Excavation With Near-Infrared Autofluorescence: Multimodal Imaging Study

Purpose: To compare the spatial concordance of autofluorescence abnormalities on near-infrared fundus autofluorescence (NIRAF) and short-wavelength fundus autofluorescence (SWAF) with the area of focal choroidal excavation (FCE) defined on en face optical coherence tomography (OCT). Methods: In this retrospective cross-sectional observational study, a 6 × 6-mm en face swept-source OCT image centered on the fovea was used to define the structural FCE area on a choroidal slab. After image registration, areas of abnormal autofluorescence, including hypoautofluorescence and hyperautofluorescence, were delineated on SWAF and NIRAF. Spatial concordance between the en face OCT-defined FCE area and the abnormal autofluorescence areas was evaluated using the Dice similarity coefficient (DSC). Results: Twenty eyes of 20 patients with conforming-type FCE were included. The mean FCE area was 0.708 ± 0.571 mm2 on en face OCT, 1.174 ± 1.196 mm2 on NIRAF (P = 0.534 vs. en face OCT), and 0.152 ± 0.203 mm2 on SWAF (P < 0.001 vs. en face OCT). Spatial concordance with en face OCT was significantly greater for NIRAF (DSC, 0.654 ± 0.187) than for SWAF (DSC, 0.160 ± 0.214; P < 0.001). NIRAF detected abnormal autofluorescence corresponding to the FCE area in all eyes, whereas SWAF failed to detect any abnormality in six eyes (30%). Conclusions: FCE-associated abnormalities on NIRAF showed greater spatial concordance with the FCE area defined on en face OCT than those on SWAF. Translational Relevance: NIRAF offers a reproducible, noninvasive means of spatially mapping melanin-associated autofluorescence abnormalities, supporting more precise multimodal characterization of FCE.