Normal visual field test results following glaucomatous visual field end points in the Ocular Hypertension Treatment Study

Objective: To compare the occurrence of normal visual field (VF) test results following 2 vs 3 consecutive, abnormal, reliable test results in the Ocular Hypertension Treatment Study. Methods: The Ocular Hypertension Treatment Study is a prospective, multicenter follow-up study as part of a longitudinal randomized clinical trial. Sixty-four (68 eyes) of 1636 participants developed a VF primary open-angle glaucoma (POAG) end point. We compared the proportion of normal VF test results after a VF POAG end point among eyes whose VF abnormality was confirmed by 2 (n=9 eyes) vs 3 (n=59 eyes) consecutive, abnormal, reliable VF test results. Results: The proportion of VF test results that were normal subsequent to a VF POAG end point in eyes whose abnormality was confirmed by 2 consecutive, abnormal, reliable test results was significantly higher (73 [66%] of 110) compared with eyes whose abnormality was confirmed by 3 consecutive, abnormal, reliable test results (46 [12%] of 381) (P=.01). Conclusions: A VF POAG end point confirmed by 3 consecutive, abnormal, reliable VF test results appears to have greater specificity and stability than either 1 or 2 consecutive, abnormal, reliable VF test results. However, some eyes whose VF POAG end point was confirmed by 3 consecutive, abnormal, reliable test results nonetheless had 1 or more normal test results on follow-up.