To evaluate the relationship between retinal nerve fibre layer (RNFL) thickness measured by optical coherence tomography (OCT) and light threshold values. Methods: 16 glaucoma patients were included. Thickness of the RNFL around the optic disc was performed at the same visit. Average RNFL thickness and average threshold of retinal sensitivity are measured for each quadrant. Results: Correlation between average FNFL thickness and average threshold of retinal sensitively showed statistically significant correlation in lower temporal quadrant where more reduction of RNFL thickness. Conclusions: Structure- function associations may strong when loss of nerve fibres is severe. However, significant reduction in retinal sensilivity does not emerge until the atrophy of nerve fibres is severs.