FOVEAL DYSFUNCTION AND CENTRAL VISUAL-FIELD LOSS IN GLAUCOMA

Objective: To determine whether foveal function distal to the ganglion cell layer is an independent predictor of central visual field functi on in glaucoma. Setting: University affiliated hospital and private pr actice. Participants: Twenty-seven eyes (27 patients) with normal-pres sure glaucoma, 10 eyes (10 patients) with primary open-angle glaucoma, and 47 eyes of 47 matched normal volunteers. intervention and Main Ou tcome Measures: Foveal cone electroretinogram (ERG) amplitude, relativ e optic cup to disc area and their relations to Humphrey full-threshol d 30-2 visual field central 4-point mean total deviation (C4MTD) and p attern deviation (C4MPD). Results: Foveal cone ERG amplitude was subno rmal in 14 (37.8%) of the 37 glaucomatous eyes and lower in the glauco ma group compared with normal eyes (P<.01). The C4MTD and C4MPD were l ower in glaucomatous eyes with subnormal amplitudes compared with thos e with normal amplitudes (P<.01 and P<.05, respectively). Amplitude wa s directly correlated with C4MTD (P<.01) and C4MPD (P<.01). Relative o ptic cup to disc area was inversely correlated with C4MTD (P<.001) and C4MPD (P<.001). Partial correlation analysis revealed that amplitude and relative optic cup to disc area were independent predictors of C4M TD and C4MPD. Conclusion: Foveal function distal to the ganglion cell layer and optic disc cupping independently predict central visual fiel d function in glaucoma.