1. Disease-specific assessment of Vision Impairment in Low Luminance (VILL) in age-related macular degeneration – a MACUSTAR study report
- Author
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Terheyden, J.H., Pondorfer, S.G., Behning, C., Berger, M., Carlton, J., Rowen, D., Bouchet, C., Poor, S., Luhmann, U.F.O., Leal, S., Holz, F.G., Butt, T., Brazier, J., Finger, R.P., and the MACUSTAR consortium
- Abstract
Background/Aims: To further validate the Vision Impairment in Low Luminance (VILL) questionnaire, which captures visual functioning and vision-related quality of life under low luminance, low contrast conditions relevant to age-related macular degeneration (AMD).\ud \ud Methods: The VILL was translated from German into English (UK), Danish, Dutch, French, Italian and Portuguese. Rasch analysis was used to assess psychometric characteristics of 716 participants (65% female, mean age 72±7 years, 82% intermediate AMD) from the baseline visit of the MACUSTAR study. In a sub-set of participants (n=301), test-retest reliability (intra-class correlation coefficient, ICC; coefficient of repeatability, CoR) and construct validity were assessed.\ud \ud Results: Four items were removed from the VILL-37 due to misfit. The resulting VILL-33 has three subscales with no disordered thresholds and no misfitting items. No differential item functioning and no multidimensionality were observed. Person reliability and person separation index were 0.91 and 3.27 for the reading subscale (VILL-R), 0.87 and 2.58 for the mobility subscale (VILL-M) and 0.78 and 1.90 for the emotional subscale (VILL-E). ICC and CoR were 0.92 and 1.9 for VILL-R, 0.93 and 1.8 for VILL-M and 0.82 and 5.0 for VILL-E. Reported visionrelated quality of life decreased with advanced AMD stage (p
- Published
- 2022