Johnson TV, et al. - In this secondary analysis of prerandomization data from two prospective, multicenter, randomized clinical trials, researchers evaluated the effectiveness of topical ocular hypotensive medications in individuals with open-angle glaucoma and identified factors correlated with postwashout intraocular pressure (IOP) elevation. For this analysis, 1400 patients (1400 eyes), mean (SD) age was 70.7 (8.0) years and 55.6% were female, with primary open-angle glaucoma who were using 0 to 4 classes of topical IOP-lowering medication had Goldmann applanation tonometry before and after a protocol-defined washout period. There has been no difference in postwashout IOP change among individual prostaglandin analogues in patients on monotherapy. A generalized linear model reported the following factors to be related to higher increase in IOP following medication washout: greater number of glaucoma medications, higher unmedicated IOP, thinner CCT, lack of prior selective laser trabeculoplasty, and male sex. Cessation of glaucoma medication leads to a rise in dose-dependent IOP in patients treated with open-angle glaucoma. Two independent clinical trial cohorts display comparable levels of IOP elevation upon washout, utilizing standardized methodology  to measure the efficacy of real-world medication.