Point-to-Point Macular Structure-Function Relationships in Healthy and Glaucomatous Eyes Using OCT and Microperimetry

Purpose: To explore anatomically adjusted point-to-point relationships between macular sensitivity and intraretinal layer thickness in healthy and glaucomatous eyes using combined optical coherence tomography (OCT) and microperimetry. Methods: Seventy-two eyes were included (27 healthy controls and 45 eyes with primary open-angle glaucoma). Retinal sensitivity was assessed using MP-1 microperimetry, and retinal structure was evaluated with Spectralis OCT. Automatic segmentations included macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), GCL + IPL, ganglion cell complex (mRNFL + GCL + IPL), and the outer retinal layer. Microperimetry maps were anatomically aligned with OCT grids using vascular landmarks, and ganglion cell displacement was considered when analyzing inner retinal layers. Thickness measurements were obtained at corresponding anatomical points, and structure-function associations were assessed using Spearman correlation analysis to generate spatial correlation maps. Results: Almost no significant pointwise correlations were detected in healthy eyes across any retinal segmentation. In glaucomatous eyes, significant positive correlations were observed for inner retinal layers, whereas no significant associations were found for the outer retinal layer. Distinct spatial patterns were identified, with peripheral correlations for mRNFL and paracentral temporal correlations for GCL, IPL, and GCL + IPL. The highest number of significant associations was observed for the ganglion cell complex. Conclusions: Anatomically adjusted pointwise analysis revealed localized and heterogeneous patterns of macular structure-function coupling predominantly involving ganglion cell-related layers in glaucoma. High-resolution mapping may uncover spatial relationships that are partially obscured by regional or spatially averaged approaches and should be interpreted as a complementary exploratory strategy rather than a replacement for established regional analyses.