Table 11: Summary of Studies Using an 8-Hour (“Office-Hour”) Diurnal Curve for IOP Measurement.

Study, Year	Design	Population	Objective	IOP Parameters	Statistical Method	Timing of IOP Measurement	Results	Comment
Malmo OHTS, 2005 (22)	Retrospective analysis of RCT N=90 eyes	Ocular hypertension Participated in RCT for topical timolol vs. placebo	To study the effect of IOP fluctuations on the incidence of glaucomatous VF loss in patients with ocular hypertension.	Mean Range Peak	Cox multivariable analysis	Diurnal curve 8am, 11:30am and 3:30 pm obtained every 3 months.	Mean followup 8.5 years Cox Multivariable Analysis: Mean IOP of all measurements Risk 1.21 (1.09 to 1.38), P=0.005 Mean of daily range Risk 1.13 (0.80 to 1.60), P=0.49 Cox Univariate Analysis (Different parameters for IOP level) Mean of all IOP Risk 1.23 (1.08 to 1.39), P=0.0013 Mean of maximum IOP Risk 1.20 (1.07 to 1.36), P=0.0027 Mean of random IOP 1.22 (1.08 to 1.38), P=0.0017 Cox Univariate Analyses (Different parameters for IOP variability) Mean of daily range Risk (0.98 to 1.93), P=0.06 Maximum of all daily ranges Risk 1.04 (0.91 to 1.19), P=0.58 Range between minimum and maxi um IOP of all measurements Risk 1.02 (0.95 to 1.09), P=0.56	IOP measured during office hours. No published studies establish the optimum number of IOP measurements during office hours.
Bergea et al. 1999 (23)	Prospective? Secondary objective of a RCT. N=76 eyes 55 Exfoliative 21 Simple	Newly detected high pressure OAG. Participated in RCT comparing argon laser trabeculoplasty compared with pilocarpine.	To investigate the correlation of different parameters of IOP visual field decay in open angle glaucoma.	Mean Range Peak	Hierarchical linear regression analysis and principal component analysis	Daytime diurnal curve (8am, 12pm and 3pm) obtained every second month	Followup period=24 months. 2 models were used. Hierarchical Linear Regression Model (VF progression linear over time) IOP peak or range P>0.05 Hierarchical Regression with Partition into Quintiles (nonlinear VF progressions over time) Mean IOP P>0.003	55% of patients had exfoliative glaucoma. Prior to risk analysis, the authors carried out principal-component analysis to avoid multicollinearity (avoid highly intercorrelated explanatory variables in the same model). This produced a number of multivariate regression models including different IOP parameters. Two of them included IOP range similar to the Malmo OHTS study. In 1 of the 2 regression models IOP range was combined with untreated baseline IOP and in the other with IOP % change (i.e., treatment effect calculated as the difference between untreated baseline IOP and mean of treated followup IOP divided by IOP at start). Therefore, the effects of followup IOP level and followup IOP fluctuation were not simultaneously tested in the same model. No published studies establish the optimum number of IOP measurements

IOP refers to intraocular pressure; NTG, normal tension glaucoma; OAG, open angle glaucoma; RCT, randomized controlled trial; SD, standard deviation; VF, visual field