Structure-function relationship in a series of glaucoma cases

Summary Purpose To map retinal sensitivity and peripapillary retinal nerve fiber layer (RNFL) thickness, as measured by standard automated perimetry (SAP) and optical coherence tomography (OCT) respectively, in patients with various stages of primary open-angle glaucoma (POAG). Methods Ninety patients with POAG were prospectively selected for SAP and for OCT RNFL thickness measurements. Factorial analysis performed independently for each hemifield was used to identify groups of related SAP visual field points. Pearson correlation coefficients were determined between visual field regions and peripapillary RNFL sectors and these data used to construct structure-function correlation maps for the various disease stages. Results Factorial analysis identified 4 factors or visual field regions for the inferior hemifield and 5 for the superior hemifield. For all patients and the subset of patients with advanced POAG, the strongest correlation was detected between the superior hemifield and the inferior RNFL sectors, while higher correlations for incipient and moderate disease stages were observed between the inferior hemifield and the superior RNFL sectors. Conclusions In these patients, functional and structural damage can be mapped such that each zone of related SAP points correlates with one or several peripapillary RNFL zones. Such maps could improve our understanding of structure-function relationships in glaucoma.