title: Primary open-angle glaucoma.
abstract: Glaucoma is an optic neuropathy that is characterized by the progressive degeneration of the optic nerve, leading to visual impairment. Glaucoma is the main cause of irreversible blindness worldwide, but typically remains asymptomatic until very severe. Open-angle glaucoma comprises the majority of cases in the United States and western Europe, of which, primary open-angle glaucoma (POAG) is the most common type. By contrast, in China and other Asian countries, angle-closure glaucoma is highly prevalent. These two types of glaucoma are characterized based on the anatomic configuration of the aqueous humour outflow pathway. The pathophysiology of POAG is not well understood, but it is an optic neuropathy that is thought to be associated with intraocular pressure (IOP)-related damage to the optic nerve head and resultant loss of retinal ganglion cells (RGCs). POAG is generally diagnosed during routine eye examination, which includes fundoscopic evaluation and visual field assessment (using perimetry). An increase in IOP, measured by tonometry, is not essential for diagnosis. Management of POAG includes topical drug therapies and surgery to reduce IOP, although new therapies targeting neuroprotection of RGCs and axonal regeneration are under development.
authors.affiliation: Shiley Eye Institute, Hamilton Glaucoma Center, Department of Ophthalmology, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Christopher K S
authors.initials: CK
authors.lastname: Leung
authors.affiliation: Department of Ophthalmology, Centre for Eye Research Australia, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Crowston
authors.affiliation: Shiley Eye Institute, Hamilton Glaucoma Center, Department of Ophthalmology, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Medeiros
authors.affiliation: Dana Center for Preventive Ophthalmology, Johns Hopkins Wilmer Eye Institute, Baltimore, Maryland, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.affiliation: Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Janey L
authors.initials: JL
authors.lastname: Wiggs
authors.affiliation: Department of Ophthalmology and Cambridge NIHR Biomedical Research Centre, University of Cambridge, Cambridge, UK.
authors.forename: Keith R
authors.initials: KR
authors.lastname: Martin