Individual Differences in Foveal Shape: Feasibility of Individual Maps Between Structure and Function Within the Macular Region

PURPOSE. Recently in glaucoma, different mapping schemes to combine structural and functional information within the macula have been proposed. This paper aims to investigate whether the changes in foveal shape parameters are important in the mapping between structure and function within the macular region. METHODS. Twenty younger adults (aged 24- to 33-years old) and 10 older adults (aged 62- to 76-years old) participated. On each subject, four foveally-centered radial spectral-domain optical coherence tomography (SD-OCT) scans with 45 degrees of separation between each scan were acquired. After scan acquisition, foveal shape was extracted by fitting a previously proposed model that has been used to customize structure-function mapping in the macular region. Three parameters were obtained from the scans and then compared: the central thickness, the maximum thickness, and the radius. RESULTS. There were significant differences in the foveal shape parameters between subjects. There was no main effect of the scan axis for the central thickness; however, there was an interaction between the scan axis and maximum thickness and between the scan axis and radius. With respect to the effect of age, we did not find a main effect for the central thickness, the maximum thickness or the radius, although this parameter approached statistical significance. CONCLUSIONS. In our study, we demonstrated that the foveal shape is different for different subjects, but predictable superiorly and inferiorly within an individual. Our study highlights features important for the development of individually customized structure-function maps for the investigation of glaucomatous damage in the macular region.