Once a diagnosis of COAG has been made, the patient normally requires lifelong monitoring of their intraocular pressures, optic discs and visual fields. In most cases, COAG can be stabilised with medication in the form of eye drops, but a small proportion of patients may require surgery. The diagnosis is not always clear-cut, and patients may be kept under observation as glaucoma suspects for variable periods.

The aim of detecting, monitoring and treating glaucoma is to prevent further progression of t he damage that glaucoma causes to optic nerve fibres. Established visual field defects due to glaucoma cannot be reversed. The main risk factor for disabling visual loss from glaucoma is late detection. There is a gradual loss of optic nerve fibres which occurs naturally with age and although this is too slow to be important in healthy people, it may become significant in a person with advanced glaucoma, however well their glaucoma is controlled.

The goal of medical and surgical treatment of glaucoma is to reduce the intraocular pressure to a low enough level that any subsequent deterioration in optic nerve function is due to aging alone and it is possible to achieve something close to that ideal in a large proportion of patients. However, some patients do not take their treatment reliably and some forms of glaucoma (eg “normal tension” glaucoma and paediatric glaucoma) are inherently more difficult to treat. Stability in glaucoma cannot therefore be taken for granted and life-long monitoring is required, particularly as it is not possible for patients to detect slow changes in the pressure or visual fields themselves.