[A further discussion of the classification and definition of primary angle closure glaucoma].

ISGEO classification was proposed as the diagnostic criterion of primary angle closure glaucoma in epidemiological prevalence survey, which is preferable to be used in epidemiology rather than employing as a clinical diagnostic criterion. A different classification means a different definition. To unify the different point-views on the ISGEO classification, a further understanding of glaucoma definition is discussed and reviewed.