Comparing Structure-Function Relationships Based on Drasdo's and Sjostrand's Retinal Ganglion Cell Displacement Models

PURPOSE. To compare structure-function relationships based on the Drasdo and Sjostrand retinal ganglion cell displacement models. METHODS. Single eyes from 305 patients with glaucoma and 55 heathy participants were included in this multicenter, cross-sectional study. The ganglion cell and inner plexiform layer (GCIPL) thickness was measured using spectral domain optical coherence tomography. Visual field measurements were performed using the Humphrey 10-2 test. All A-scan pixels (128 x 512 pixels) were allocated to the closest 10-2 location with both displacement models using degree and millimeter scales. Structure-function relationships were investigated between GCIPL thickness and corresponding visual sensitivity in nonlong (160 eyes) and long (200 eyes) axial length (AL) groups. RESULTS. In both the nonlong and long AL groups, compared with the no-displacement model, both the Drasdo and the Sjostrand models showed that the structure-function relationship around the fovea improved (P < 0.05). The magnitude of improvement in the area was either comparable between the model or was larger for the Drasdo model than the Sjostrand model (P < 0.05). Meanwhile, structure-function relationships outside the innermost retinal region that were based on the Drasdo and Sjostrand models were comparable to or were even worse than (in the case of the Drasdo model) those obtained using the no-displacement model. CONCLUSIONS. Structure-function relationships evaluated based on both the Drasdo and Sjostrand models significantly improved around the fovea, particularly when using the Drasdo model. This was not the case in other areas.