In this episode, we discuss the role of Intraocular Pressure (IOP) in Normal Tension Glaucoma & the natural history of the condition as determined in the Normal Tension Glaucoma Study. Stephen Drance, MD, FRCSC, is Professor Emeritus UBC Ophthalmology & Visual Sciences and an Officer of the Order of Canada. He was the co-lead investigator for the Normal Tension Glaucoma studies, popularized the importance of disc hemorrahges in glaucoma which bear his name, and has made many other contributions to much of our current understanding of glaucoma.