Project Summary This application is for secondary analyses to determine the long-term effect of treatment, clinical and demographic factors on vision-related quality of life (VRQOL) in the Ocular Hypertension Treatment Study (OHTS) cohort. This application is timely because the US Preventative Services Task Force recently concluded there was “Inadequate evidence that treatment of primary open-angle glaucoma improves health outcomes such as reduced visual impairment, vision-related function, and quality of life” (JAMA Ophthal, May 2022). OHTS is the only US study with 20-year clinical and VRQOL outcomes in a cohort of 1,636 participants with ocular hypertension. The 20 year follow-up is meaningful because it approaches the life expectation of participants whose median age was 55 at baseline. Aim 1 will report cross-sectional 20 year data from the National Eye Institute Visual Function Questionnaire (NEI VFQ) and 15 item Glaucoma Quality Life survey (GQL-15). Aim 2 will focus on longitudinal changes in clinical and VRQOL in the inception cohort of participants who developed POAG in OHTS 1 or 2. Pre-POAG VRQOL data collected in the inception cohort will allow statistical adjustment for individual differences on post-POAG VRQOL which will increase precision of post-POAG impact on VRQOL. Accurate dates of POAG diagnosis in the inception cohort will enable a rigorous test of the effect of duration and rate of change in clinical parameters on VRQOL. We will analyze treatment, clinical and demographic factors affecting VRQOL in the cross-sectional sample at 20 years of follow-up (Aim 1) and in the longitudinal cohort sample (Aim 2). Core tests and measures were completed per protocol at 6 month intervals for 13 years and at 1-3 visits after 20 years of follow-up. Tests and measures to be analyzed include indices from Humphrey 30-2 SITA standard visual fields, best corrected acuity, Pelli-Robson contrast sensitivity, and OCT (assessed at 20 years). VRQOL was assessed using the NEI-VFQ administered every 2 years for 13 years and the GQL-15 administered at 20 years.