The Fast Component of Visual Field Decay Rate Correlates With Disc Rim Area Change Throughout the Entire Range of Glaucomatous Damage

PURPOSE We investigated the longitudinal relationships between the changes in neuroretinal rim area (RA) and the slow (SC) and fast (FC) components of visual field (VF) decay at various stages of glaucoma. METHODS We divided 465 eyes of 338 patients into glaucoma suspect, and preperimetric, early, and moderate/advanced glaucoma. All patients had a minimum of 3 confocal scanning laser ophthalmoscopic examinations and 4 VF tests with follow-up of 4 or more years. A pointwise exponential regression was used to perform trend analyses on thresholds at each VF test location, which was partitioned into SC and FC. A mixed effects linear model was used to explore the associations of RA change with mean deviation (MD), visual field index (VFI), SC, and FC. RESULTS Decreased RA was associated with lower mean threshold sensitivities of FC regardless of baseline severity of glaucoma (P ≤ 0.03). The mean threshold sensitivities in SC were not correlated with RA change at any stage. Decreased RA was correlated with worse MD in preperimetric, early, and moderate/advanced glaucoma (P < 0.05). Decreased RA was correlated with worse VFI in preperimetric and early glaucoma only (P ≤ 0.04). CONCLUSIONS A decrease in rim area was significantly correlated with the fast VF component regardless of the baseline severity of glaucoma. Mean deviation and VFI correlated with change of rim area only in certain stages of glaucoma. The identification of the fast component seems a more robust and useful measure of glaucomatous change than MD or VFI.