Is Diurnal IOP Fluctuation Associated with Glaucoma?
The major randomised clinical trials (RCTs) published on glaucoma over the past few years have provided strong and irrefutable evidence for treatment by reduction of IOP. These trials were reviewed in the OGS EJ volume 1 issue 2. Although each of these addresses a specific question, there is little doubt that their consensus indicates IOP lowering improves the glaucoma prognosis, in terms of both reducing the risk of initial development in ocular hypertension, (1) and of progression in those with an existing glaucoma diagnosis (2, 3, 4). RCTs provide highest quality methodology for investigating the effects of an exposure, such as IOP lowering, on an outcome, such as glaucoma progression. The reasons for this are (a) they estimate the group effect of the exposure on the outcome and (b) they minimize the potentially devastating effects of bias and confounding effects that may inadvertently produce spurious results in other study designs. However, interpretation and generalisation of RCT
