In the article titled “Single vs Multiple Intraocular Pressure Measurements in Glaucoma Surgical Trials,” published online May 15, 2014, and also in the August print issue of JAMA Ophthalmology (2014;132[8]:956-962. doi:10.1001/jamaophthalmol.2014.867), an error occurred in Figure 3 on page 961. In the P Value column, the values should have been shifted down by one row, with no value in the top row (correlating to Time [reference, 12 pm]). This article was corrected online.