Researchers imaged a large series of consecutive normal and primary open-angle glaucoma subjects to evaluate the ability of HRT3 sectorial analysis to discriminate between healthy and glaucomatous eyes. While sectorial analysis overall has higher diagnostic accuracy than global analysis, neither HRT parameters nor classification algorithms seem to be good at the earlier stage of the disease. After stratifying subjects by disc size, they determined that small discs are classified more accurately by examining the inferonasal sector, whereas larger discs are classified more accurately by examining the inferotemporal sector. Ophthalmology, June 2009.