The role of photopic negative response(PhNR)and pattern electroretinogram(PERG)was assessed as diagnostic indicator of glaucoma. Ten control subjects and 15 patients with early glaucoma underwent complete ophthalmological examination including visual acuity measurement, intraocular pressure(IOP)measurement, fundus examination and visual field examination. Pattern ERG and photopic full-field ERG were performed. Mean deviation(MD)and pattern standard deviation(PSD)means were significantly reduced in glaucoma group(P<0.001 and P<0.01). The amplitudes of PERG N95, PhNR, b-wave and the PhNR/b-wave ratio were significantly reduced(P<0.001). The rise in IOP resulted in reduction of PERG and PhNR amplitude.