Hong SW, et al. - Researchers evaluated the variability of 5 glaucoma specialists’ optic disc margin (DM), rim margin (RM) and rim width (RW) estimates. They viewed stereo-photos from subjects with glaucoma or ocular hypertension and digitally marked the DM and RM. The centroid of each clinician’s DM for each photo was calculated, and an averaged DMcentroid was determined. The median COV by sector ranged from 3-5% for DMradius, 20-25% for RMradius, and 26-30% for RW among all eyes. For CDR, Sectoral ICCs ranged from 0.566 to 0.668. Frequent and substantial glaucoma specialist RM, DM and RW discordance was seen in sectors that were suspicious for rim thinning.