Katz Joanne M.S.; Gilbert, Donna; Quigley, Harry A. M.D.; Sommer, Alfred M.D., M.H.S.Journal of Glaucoma: July 1992 Original Article: PDF Only Buy Abstract Summary The effect of test duration on fixation losses, and false-positive and false-negative catch trial responses was examined in 361 eyes of 203 ocular hypertensive patients. These were recorded at 5-min intervals during automated perimetric testing with the Humphrey field analyzer's C-30–2 program. There was no statistically significant change in the distribution of false-positive and -negative response rates as the test progressed, hut the proportion of tests with at least one false-negative response per 5-min interval did increase toward the end of the test. Fixation losses were common and showed no consistent pattern over the course of testing, but were related to technician test administration technique. Test duration did not appear to affect catch trial responses over the course of testing. © Williams & Wilkins 1992. All Rights Reserved.