The authors describe a comparison of spectral domain OCT with Humphrey visual fields (HVF) mean deviation (MD) and pattern standard deviation (PSD), examining the retinal thickness of the macula and circumpapillary retinal nerve fibre layer (RNFL) defects. Seventy-three subjects who met the study criteria were analysed retrospectively. Patients were either diagnosed with glaucoma or glaucoma suspects. Both eyes were included and were analysed separately. The total average macular thickness plus the average macular thickness in superior and inferior macular halves as well as differences in total and macular half-thickness between the right and left eyes were examined. The average thicknesses of the circumpapillary RNFL in the superotemporal and inferotemporal quadrants for each eye were also recorded. MD and PSD HVF parameters were included and asymmetry between the eyes. The cup-to-disc (CD) ratio was also recorded. Correlations were determined using linear regression analysis. The authors found that eyes with a total macular thickness of <270 microns were significantly more likely to be associated with visual field loss by both MD and PSD. Whereas eyes with a total thickness of >300 microns were less likely to be associated with visual field losses. Also, when comparing the two eyes to each other or the superior macular to the inferior macular the visual field loss was associated to the thinner retina or retinal half. The authors demonstrated a strong correlation between RNFL and macular thickness measurements in glaucoma and showed how measurement of both the RNFL and macular thickness could provide useful additional information in the diagnosis and management of glaucoma patients.