Spatial and temporal summations in the photopic and mesopic state of adaptation were studied in areas of relative visual field disturbance in patients with chronic simple glaucoma. Neither of these modalities of psychovisual testing was more disturbed than the differential threshold. Neither modality therefore offers promise of detecting earlier glaucomatous disturbances than profile perimetry.
Dannheim F, Drance SM. Psychovisual Disturbances in GlaucomaA Study of Temporal and Spatial Summation. Arch Ophthalmol. 1974;91(6):463-468. doi:10.1001/archopht.1974.03900060477010