The relationship between colour vision defects and visual field tests in glaucoma

Purpose The relationship between colour vision defects (CVD) and visual field test results in glaucoma can be counterintuitive. We sought to examine the relationship between three tests of colour vision and three types of perimetry in glaucoma. Materials and methods In this cross-sectional study, we included both eyes of 53 patients with glaucoma. We conducted white-on-white Standard Automated Perimetry (SAP), blue-on-yellow Short Wave Automatic Perimetry (SWAP) and sine-grating Frequency Doubling Technology (FDT) perimetry, as well as Ishihara, Hardy-Rand-Rittler (HRR) and desaturated Lanthony D-15 tests of central colour vision. Our primary analysis used Kendall’s tau to measure the probability that an increase in one variable, the average of SAP or SWAP of FDT central point sensitivities, is accompanied by concordant increase in colour vision. Results There are weak concordances between D15 and SAP (-0.01 ≤ τ ≤ 0.21), D15 and SWAP (-0.03 ≤ τ ≤ 0.22), and D15 and FPT (0.03 ≤ τ ≤ 0.30). There was insufficient evidence in the sample to conclude that these concordances differ (p = 0.08). There appear to be stronger concordances between HRR and the results of visual field tests (0.09 ≤ τ), the strongest being with FDT (0.13 ≤ τ). Conclusions The effect of glaucoma on colour vision appears to be diffuse, not closely concordant with overall or central visual field function.