Structure-function relationship in glaucoma using spectral-domain optical coherence tomography

Abstract

Objectives: To determine the structure-function relationship in glaucoma using spectral-domain optical coherence tomography (SDOCT)-derived structural measurements and to evaluate this relationship using a linear model.

Methods: In a cross-sectional study, structure-function relationships were determined for all the participants in the DIGS (Diagnostic Innovations in Glaucoma Study) and the ADAGES (African Descent and Glaucoma Evaluation Study) who had undergone standard automated perimetry (SAP) and SDOCT within 6 months of each other. Strength of relationship was reported as coefficient of determination (R(2)). The relationship was also evaluated using a previously described linear model.

Results: The results of 579 SAP and SDOCT examinations from 80 eyes of 47 control subjects, 199 eyes of 130 patients with suspected glaucoma, and 213 eyes of 146 patients with glaucoma were analyzed. The R(2) for the association between SAP total deviation and SDOCT variables ranged from 0.01 (P = .02) for the nasal rim area to 0.30 (P < .001) for inferior inner retinal thickness at the macula. The linear model fitted the data well.

Conclusions: The strongest structure-function associations using SDOCT were found for retinal nerve fiber layer measurements at arcuate areas and inner retinal thickness at the macula measurements. The linear model is useful in studying the structure-function relationship in glaucoma.

Figure 1

The relationship between visual field sectors and optic disc regions/retinal nerve fiber layer quadrants based on the map by Garway-Heath et al. The square centered on the fovea shows the area used to assess the relationship between central visual field sectors and macular regions.

Figure 2

Linear model showing the relationship between inferotemporal retinal nerve fiber layer (RNFL) thickness and superonasal sector visual sensitivity loss. Solid black line represents the lowess curve fitting our data. Dashed line and the two short dashed lines above and below the dashed line represent the 50^th, 95^th and 5^th percentile of the model.

Figure 3

Linear model showing the relationship between superotemporal retinal nerve fiber layer (RNFL) thickness and inferonasal sector visual sensitivity loss. Solid black line represents the lowess curve fitting our data. Dashed line and the two short dashed lines above and below the dashed line represent the 50^th, 95^th and 5^th percentile of the model.

Figure 4

Linear model showing the relationship between inferotemporal retinal nerve fiber layer (RNFL) thickness and superonasal sector visual sensitivity loss. Solid black line represents the lowess curve fitting our data. Dashed line and the two short dashed lines above and below the dashed line represent the 50^th, 95^th and 5^th percentile of the model.

Figure 5

Linear model showing the relationship between superotemporal retinal nerve fiber layer (RNFL) thickness and inferonasal sector visual sensitivity loss. Solid black line represents the lowess curve fitting our data. Dashed line and the two short dashed lines above and below the dashed line represent the 50^th, 95^th and 5^th percentile of the model.