This study examined over 4000 retinal nerve fibre layer (RNFL) OCT scans over a five year period of follow up in patients with glaucoma. Their findings confirm that progressive RNFL thinning (i.e. a change in optic nerve structure detected by OCT scans) can predict functional deterioration (i.e. progressive visual field loss) in glaucoma. This underscores the importance and relevance of regular RNFL OCT scans, where clinically appropriate, in patients with glaucoma at risk of progression.