Criteria for success of surgical treatment of glaucoma

Outcome measures for studies of the surgical treatment of glaucoma include intraocular pressure, functional status (usually with visual field measurements), and structural status of the optic nerve or nerve fiber layer. Older studies relied heavily and almost solely on intraocular pressure as a surrogate measure for expected glaucomatous damage, but the situation is improving. It is clear that functional outcomes must be used in the evaluation of surgical therapy (indeed, of all therapy) for glaucoma whenever feasible. Measurements of structural damage are also important in patients with early or suspected damage. Structural evaluations probably do not provide information beyond that derived from visual field measurements in patients with advanced glaucomatous damage. This paper surveys the criteria and methods used to determine success in recent studies of glaucoma surgery and makes recommendations about the most appropriate outcome measures for surgical studies of glaucoma treatment.