Point-wise relationships between visual field sensitivity and macular thickness determined by spectral-domain optical coherence tomography

Purpose: To evaluate the point-wise relationships between visual field sensitivity (VFS), as measured by standard automated perimetry (SAP), and macular thickness, as determined by spectral-domain optical coherence tomography (SD-OCT), in patients with glaucoma. Materials and methods: One hundred and six glaucoma subjects (one eye per subject) recruited from an academic institution underwent SAP tests (Humphrey field analyzer, central 24-2 of Swedish Interactive Thresholding Algorithm standard) and SD-OCT volume scans (SPECTRALIS, posterior pole asymmetry analysis). The retinal sensitivities of 16 central test points from the SAP results were recorded. Macular thickness values from 4 square cells in an 8×8 posterior pole retinal thickness map were averaged for a mean retinal thickness (MRT) value, which corresponded to the 16 central test points in the SAP. In each 16-point area, linear regression analyses of the VFS and the MRT value were performed. Results: The VFS of each 16 central test point showed a significant relationship with the corresponding MRT values (R²=0.133-0.383, all p<0.001). Central and nasal test points corresponding to an arcuate region revealed a relatively strong correlation in both the superior and inferior hemispheres (R²=0.311- 0.383 and 0.288-0.345, respectively), but the superior and inferior-temporal points revealed a relatively weaker correlation (R²=0.149 and 0.133, respectively). Conclusions: The VFS showed a significant reciprocal relationship with corresponding macular thickness at each test point. However, the level of the relationship varied among different macular sectors, showing the strongest relationship in the arcuate region.