To determine the existence of retinal ganglion cell dysfunction and associated risk factors in glaucoma suspects with increased optic disc cupping and normal visual field. Cross-sectional, observational study. Two hundred glaucoma suspec t (GS) patients were identified based on optic disc abnormalities (vertical cup -to-disc ratios [C/D] >0.5; vertical C/D asymmetry ≥0.2; disc hemorrhages; no tching) in association with known glaucoma risk factors (positive family history , African American descent, increased intraocular pressure [IOP]), but normal vi sual fields. Forty-two patients had early manifest glaucoma (EMG). Sixteen norm al black subjects were added to update previous pattern electroretinogram (PERG) normative data and to establish a normal control (NC) group with a racial break down comparable with that of the study groups. Pattern electroretinograms were r ecorded simultaneously from both eyes using skin electrodes and automated analys is; visual fields were monitored with standard white-on-white automated perime try (SAP) central 24-2 program; vertical C/D was evaluated by an independent re ader from stereo disc photographs; and univariate and multivariate statistical a nalysis between PERG and other outcome measures was evaluated. Pattern electrore tinogram amplitude (μV), phase (π.rad), and interocular asymmetry in amplitude and phase (%); and SAP mean deviation (MD; decibels), vertical C/D, age (years ), IOP (mmHg), and race (black vs. nonblack). The PERG results were abnormal in at least 1 of the outcome measures in 52%of GS patients and 69%of EMG patients . The PERG amplitude was correlated weakly with both MD (P < 0.01) and vertical C/D (P=0.05). The correlation between PERG amplitude and MD and C/D was stronger (P < 0.001) for interocular differences rather than absolute measures. Interocu lar PERG amplitude asymmetry increased with severity of disease (EMG > GS > NC; P < 0.01). The PERG amplitude decline with age was steeper in patients with a mo re negative MD (P < 0.01) and in patients with a more negative MD and a larger v ertical C/D (P=0.06). Black race (but not family history) was associated with lo wer PERG amplitude (P=0.005) in GS and EMG patients, but not in normal controls (P=0.44). The correlation between PERG abnormality and known risk factors for gl aucoma indicates that PERG has a predictive potential for the development or pro gression of the disease, or both. To determine the existence of retinal ganglion cell dysfunction and associated risk factors in glaucoma suspects with increased optic disc cupping and normal visual field. Cross-sectional, observational study. Two hundred glaucoma suspec t (GS) patients were identified based on optic disc abnormalities ( vertical cup-to-disc ratios [C / D]> 0.5; vertical C / D asymmetry ≥ 0.2; disc hemorrhages; no tching) in association with known glaucoma risk factors (positive family history, African American descent, increased intraocular pressure [IOP ]), but normal vi sual fields. Forty-two patients had early manifest glaucoma (EMG). Sixteen norm al black subjects were added to update previous pattern electroretinogram (PERG) normative data and establish a normal control (NC) group with a racial break down comparable with that of the study groups. Pattern electroretinograms were r ecorded simultaneously from both eyes using skin electrodes and automated analys is; visual fields were monitored with standard white-on-white automated perime try (SAP) central 24-2 program; vertical C / D was evaluated by an independent re ader from stereo disc photographs; and univariate and multivariate statistical a nalysis between PERG and other outcome measures was evaluated. Pattern electroretinogram amplitude in μV, phase in π.rad, and interocular asymmetry in amplitude and phase in%; and SAP mean deviation in MD; decibels, vertical C / D, age in years, IOP in mmHg, , and race (black vs. nonblack). The PERG results were abnormal in at least 1 of the outcome measures in 52% of GS patients and 69% of EMG patients. The PERG amplitude was correlated weakly with both MD (P <0.01) The correlation between PERG amplitude and MD and C / D was stronger (P <0.001) for interocular differences rather than absolute measures. Interocu lar PERG amplitude asymmetry increased with severity of disease (EMG> GS> NC; P <0.01). The PERG amplitude decline with age was steeper in patients with a moBlack race (but not family history) was associated with lo wer PERG amplitude (P = 0.005); negative ramifications (p <0.01) and in patients with a more negative MD and a larger v ertical C / D in GS and EMG patients, but not in normal controls (P = 0.44). The correlation between PERG abnormality and known risk factors for gl aucoma indicates that PERG has a predictive potential for the development or pro gression of the disease, or both.