Utility values for glaucoma in Brazil and their correlation with visual function

Abstract

Ricardo Augusto Paletta Guedes,1–3 Vanessa Maria Paletta Guedes,1–3 Sirley Maria Freitas,2 Alfredo Chaoubah1 1Federal University of Juiz de Fora, 2Paletta Guedes Ophthalmological Center, 3Santa Casa de Misericórdia Hospital, Juiz de Fora, Brazil Purpose: We sought to identify the utility values in a group of Brazilian patients with primary open-angle glaucoma (POAG), and to assess its impact on visual acuity (VA) and mean deviation index values. Materials and methods: This was a cross-sectional study of consecutive patients with POAG, who were interviewed using three methods for obtaining utility values: time trade-off (TTO), standard gamble anchored at risk of death (SG1), and standard gamble anchored at risk of blindness (SG2). Visual function variables (VA and mean deviation index in the better eye) and sociodemographic characteristics (age, sex, race, and educational level) were also obtained for statistical analysis. Results: The mean age (± standard deviation) of the study population (n=227) was 65.7 (±15.1) years. Mean utility values for the entire population were 0.82 from TTO, 0.90 from SG1, and 0.93 from SG2 (P<0.0001). Age, race, and sex had no influence on the utility values. Higher education tended to predict higher values by TTO, but not by SG1 or SG2. Visual function variables had an influence on utility values. The more advanced the visual loss, whether measured by VA or perimetry, in the better eye, the lower the utility values by all three methods. Conclusion: We obtained utility values for Brazilian patients with POAG, as well as specific values for different levels of vision loss. Keywords: primary open-angle glaucoma, visual acuity, quality of life, utility, disease severity