SINCE 1996, the American Academy of Ophthalmology's Preferred Practice Pattern (PPP) for primary open-angle glaucoma1 has defined glaucoma as an acquired optic neuropathy with either visual field or optic nerve manifestations. Buttressed by mounting evidence that optic nerve damage generally precedes detectable visual field damage,1- 3 the PPP defines early glaucoma as having no visual field defect on routine threshold perimetry. The presence of any characteristic visual field loss defines the severity as at least moderate in nature. This, in turn, generates important clinical questions.
Lee PP. Early Detection of Moderate GlaucomaRedefining Clinical Care in 2001. Arch Ophthalmol. 2001;119(7):1069-1070. doi:10.1001/archopht.119.7.1069