Agreement among spectral-domain optical coherence tomography, standard automated perimetry, and stereophotography in the detection of glaucoma progression.

PURPOSE

The purpose of this study was to evaluate the agreement among spectral-domain optical coherence tomography, standard automated perimetry (SAP), and optic disc stereo photography in the detection of glaucomatous progression.

METHODS

This was an observational cohort study enrolling 246 eyes (148 patients) followed for an average of 31.8 ± 9 months. Images were obtained every 6 to 12 months with optical coherence tomography (OCT), visual field test, and optic disc stereo photography. Progression was determined with OCT using guided progression analysis (GPA) software, in perimetry with Humphrey field analyzer GPA, and by masked assessment of stereo photograph series. Agreement among methods was reported using the κ coefficient, prevalence-adjusted bias-adjusted κ (PABAK), Gwet's first-order agreement coefficient (AC1), overall percentage agreement (OPA), percentage of positive agreement (Ppos), and percentage of negative agreement (Pneg).

RESULTS

Progression by stereo photos, SAP, and OCT was found in 17 eyes (6.9%), 37 eyes (15%), and 63 eyes (25.6%), respectively. Most cases with detectable changes were only identified by one examination method, resulting in low Ppos (<33%). On the contrary, 147 eyes (59.7%) were identified as nonprogressing cases by all three methods, showing high OPA (72.8-89.8) and high Pneg (83.8-94.5). PABAK and AC1 between methods reached 0.67 to 0.88. Measurements of agreement showed a trend toward better agreement between photos and visual field (VF) than between photos and OCT. Spectral-domain OCT parameters reflected a tendency toward better agreement with stereo photos than with VF.

CONCLUSIONS

Methods obtained acceptable agreement outcomes in terms of PABAK, AC1, and OPA. However, most cases with detectable changes were identified only by one examination method, resulting in low Ppos.