Measurements were performed in one randomly chosen eye of 32 glaucoma patients (mean age, 61 ± 11 years; 15 men, 17 women) from the Erlangen Glaucoma Registry. This group of patients was divided into two subgroups, those with perimetric open-angle glaucoma (
n = 20; mean age, 63 ± 11 years; 10 men, 10 women) and those with preperimetric open-angle glaucoma (
n = 12; mean age, 59 ± 11 years; 5 men, 7 women) in accordance with the criteria previously established for conventional white-on-white automated perimetry, visual acuity, and IOP.
38 Briefly, the inclusion criteria were open chamber angle, increased IOP (measurements >21 mm Hg), and abnormal appearance of the optic nerve head. Additionally, all perimetric glaucoma patients displayed glaucomatous visual field defects. Mean deviations ranged from 1.2 to 23.8 (average, 9.6 ± 6.9) in the perimetric group and from −2.2 to 2.1 (average, 0.2 ± 1.4) in the preperimetric group. The control group consisted of 24 healthy volunteers (mean age, 43 ± 11 years; 14 men, 10 women).
All glaucoma patients (and the control subjects) were phakic and had clear lenses. Any eye disorder (such as cataract) other than glaucoma was an exclusion criterion. In addition, normal color vision was established. All participants underwent anomaloscope (HMC Anomaloskop; Oculus, Wetzlar, Germany) examination before the ERG measurements. The anomalous quotient (AQ) was within the normal range (0.7–1.4), according to the manufacturer's instruction manual. Perimetric patients had AQs from 0.9 to 1.4 (average, 1.19 ± 0.14), and preperimetric patients had AQs from 0.8 to 1.2 (average, 1.02 ± 0.17). Controls had AQs from 0.7 to 1.2 (average, 0.91 ± 0.03). The experiments adhered to the tenets of the Declaration of Helsinki and were approved by the institutional ethics committee. Signed informed consent was obtained from the subjects after explanation of the nature and possible consequences of the study.