Author Affiliations: Department of Ophthalmology, Stanford University, Palo Alto, California (Dr Singh); and Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota (Dr Sit).
One of the most contentious topics in ophthalmology during the past decade has been the importance of intraocular pressure (IOP) fluctuation and variability as independent risk factors for glaucoma progression, where fluctuation is defined as the change within 24 hours and variability is defined as the change during periods longer than 24 hours. Several studies have suggested that IOP variability between visits is a more important predictor of glaucoma progression than the mean IOP. Two post hoc analyses from the Advanced Glaucoma Intervention Study (AGIS), for example, showed that intervisit IOP variability strongly predicts glaucoma progression, particularly in patients with low IOP.1,2
Singh K, Sit AJ. Intraocular Pressure Variability and Glaucoma RiskComplex and Controversial. Arch Ophthalmol. 2011;129(8):1080-1081. doi:10.1001/archophthalmol.2011.66