Abstract
Abstract: :
Purpose: To determine if the quality–of–life of AMD patients with monocular visual dysfunction differs from that of those with bilateral visual dysfunction. Methods: We performed a cross–sectional study (n=168) to determine if there was a statistically significant difference in the patient–reported health related quality–of–life (HRQoL) of AMD patients who had monocular visual dysfunction as compared to those who had bilateral dysfunction. All subjects underwent a series of interviewer–administered techniques to ascertain their HRQoL, including administration of the Visual Function Index (VF–14) and patient preferences elicited through both the time tradeoff (TTO) and standard reference gamble (SRG). Patient preference methodology included the use of standardized boards and "ping–pong" techniques to obtain precise preference estimates. Visual acuity obtained from a subject’s better and worse–seeing eye was categorized into one of 4 groups; 20/20 to 20/40, 20/50 to 20/70, 20/80–20/200, and worse than 20/200. Based on the various combinations of these 4 visual acuity groupings in the better–seeing (BSE) and worse–seeing eyes (WSE), subjects were classified into one of 10 subgroups. We employed multivariate linear regression to determine if an association existed between various clinical variables including visual acuity grouping based on acuity in the BSE and WSE, and HRQoL score, as measured through TTO, VF–14 and SRG scores. Results: Our sample had a mean age of 72 years and 63% were females. The mean VF–14 score was 66.1, the mean TTO score was 0.86, and the mean SRG score was 0.89. Subjects with binocular visual dysfunction reported a significantly lower HRQoL as compared to those with monocular dysfunction (p<0.001); the mean differences in the TTO, SRG, and VF–14 were 0.19 (SE=0.04), 0.14 (SE=0.04), and 59.2 (SE=3.9), respectively. Our multivariate models demonstrated that only visual acuity sub–grouping, a function of the acuity in both the BSE and WSE, was significantly associated with HRQoL score (overall eta2 =34.8%, p<0.01, and partial eta2 equal to 22% (TTO), 20% (SRG) and 60% (VF–14)). Models including both BSE and WSE visual acuity explained an additional 10% in HRQoL variability as compared to those models with only BSE visual acuity. Conclusions: Subjects with binocular visual dysfunction reported a significantly lower HRQoL as compared to those with monocular dysfunction. These results suggest that binocular vision is a better predictor of HRQoL in AMD than only visual acuity in the better–seeing eye.
Keywords: quality of life • age–related macular degeneration • clinical (human) or epidemiologic studies: health care delivery/economics/manpower