Combining vascular and nerve fiber layer thickness measurements to model glaucomatous focal visual field loss

We compare the focal structure–function correlation of structural measurements of peripapillary retinal nerve fiber layer thickness (RNFL‐T) using optical coherence tomography (OCT), capillary density (CD) measurements using OCT‐angiography (OCT‐A), or a combination of both, with visual field deviation (VFD) in early to advanced glaucoma. Primary open angle glaucoma patients (n = 46, mean ± SD age: 67 ± 10 years; VF mean deviation: −10.41 ± 6.76 dB) were included in this cross‐sectional study. We performed 30–2 standard automated perimetry OCT (3.5‐mm diameter ring scan) and 15°×15° OCT‐A (superficial vascular complex slab). Based on a nerve fiber trajectory model, each VF test spot was assigned to an OCT‐A wedge and an OCT ring‐sector. Two univariate linear models (M(v) and M(t) ) using either CD‐based vascular (M(v) ) or RNFL‐T–based thickness information (M(t) ) and one multivariate model using both (M(v:t) ) were compared in their associations with measured focal VFD, which were higher for the multivariate model M(v:t) (mean ± SD correlation coefficient: 0.710 ± 0.086) than for either nested model (0.627 ± 0.078 for M(v) and 0.578 ± 0.095 for M(t) ). Using a focal visual field approach, the combination of RNFL‐T and CD showed better structure–function correlations than thickness or vascular information only.