Objective: To determine the ability of pattern-electroretinogram (PERG) to discriminate individual evolution of glaucomatous visual field losses in glaucoma suspects.

Methods: We studied 151 eyes of 78 GS, classified depending on their risk to develop glaucomatous damage. The initial visual field was normal. Those eyes showing at least 2 reduced amplitudes in the PERG components (P50, N95 and NP) were considered pathologic. The mean follow-up was 30 months (range: 13-50 months); the VF was evaluated at the end of the study.

Results: At the beginning of the study the PERG was pathologic in 65 eyes (43%); in 45 of these eyes (69%) the visual field was pathologic at the end of the study. The positive predictive value of the PERG of visual field glaucomatous changes was 69% and the negative predictive value was 80%. The N95 amplitude showed the best predictive value, with 100% and 77% in the high and medium risk groups, respectively.

Conclusions: The PERG study can discriminate the glaucoma suspects that will develop visual field glaucomatous losses.