RESUMO
PURPOSE: To investigate whether there is a difference in ON- and OFF-responses of the photopic electroretinogram (ERG) in glaucomatous eyes. METHODS: Photopic ERG and optical coherence tomography were performed in 15 normal, 13 glaucoma suspect, and 22 glaucoma subjects. Amplitudes and implicit times for a, b, d, i, photopic negative response (PhNR), and retinal nerve fiber layer thickness were compared among the three groups. RESULTS: The PhNROFF amplitude (microV) was 19.05 +/- 11.41 in the glaucoma group, 14.24 +/- 10.37 in the glaucoma suspect group, and 2.69 +/- 12.16 in the normal group, demonstrating a significant difference among the three groups (p < 0.01). The PhNRON amplitude (microV) was 20.15 +/- 13.99 in the glaucoma group, 31.49 +/- 17.09 in the glaucoma suspect group, and 37.59 +/- 9.53 in the normal group, a significant difference (p < 0.01). However, there was no significant difference between the three groups. The ON-OFF response PhNR amplitude was correlated with retinal nerve fiber thickness (r = 0.481, r = -0.480, respectively), and areas under the receiver operating characteristic curve were 0.782, and 0.718, respectively. CONCLUSIONS: There is a potential role for the ON-OFF response PhNR in early detection of glaucomatous damage.