Table 1.

Variation in Intraocular Pressure and the Risk of Developing Open-angle Glaucoma in Prospective Cohort Studies.

Study	Diagnostic Innovations in Glaucoma Study(DIGS)7	Malmo Ocular Hypertension Study8	European Glaucoma Prevention Study9	Ocular Hypertension Treatment Study (OHTS)10
Sample population	252 eyes of 126 untreated ocular hypertensive patients. 47 eyes of 31 subjects developed OAG during follow-up	90 patients with ocular hypertension: 44 were randomized to treatment with: placebo and 46 to timolol. 37 of them developed OAG.	1,077 patients with IOP ≥22 mmHg, who were randomized to treatment with dorzolamide or placebo. Among them, 12 developed OAG.	819 patients with ocular hypertension randomized either to topical ocular hypotensive medication or to close observation without treatment. Among them, 104 developed OAG.
Duration of follow-up	7.1 years on average	8.5 years on average	5 years on average	6.5 years (median)
Mean age	56.3 years	62 years	57.0 years36	56.1 years37
Race/ethnicity	94% NHW, 3% AA, 2% Hispanic, 2% Asian	100% NHW	99.8% NHW	70% NHW, 24.7% AA, 3.5% Hispanic37
Average IOP during follow-up	24.4 mmHg	22.7 mmHg	19.7 mmHg	21.4 mmHg
IOP variation measurement	SD of all available IOP measurements	Mean daily range of IOP	SD of follow-up IOPs	Patient-specific variance of IOP
Association with IOP variation	No significant association	No significant association	No significant association	Inverse association
Association with mean IOP	Significant association	Significant association	Significant association	-

Abbreviations: AA=African American, IOP=intraocular pressure, NHW=non-Hispanic white, OAG=open-angle glaucoma, SD=standard deviation.