title: Patient-reported utilities in bilateral visual impairment from amblyopia and age-related macular degeneration.
abstract: BACKGROUND
  Utility of visual impairment caused by amblyopia is important for the cost-effectiveness of screening for amblyopia (lazy eye, prevalence 3-3.5 %). We previously measured decrease of utility in 35-year-old persons with unilateral persistent amblyopia. The current observational case-control study aimed to measure loss of utility in patients with amblyopia with recent decrease of vision in their better eye. As these patients are rare, the sample was supplemented by patients with bilateral age-related macular degeneration with similar decrease of vision.
  
  
  METHODS
  From our out-patient department, two groups of patients with recent deterioration to bilateral visual acuity less than Snellen 0.5 (bilateral visual impairment, BVI) were recruited, with either persistent amblyopia and age-related macular degeneration (AMB + AMD), or with bilateral age-related macular degeneration (BAMD). To measure utility, the time trade-off method and the standard gamble method were applied through interviews. Correlations were sought between utility values and visual acuity, age and Visual Function Questionnaire-25 scores.
  
  
  RESULTS
  Seventeen AMB + AMD patients (mean age 72.9 years), and 63 BAMD patients (mean age 79.6 years) were included in the study. Among AMB + AMD, 80 % were willing to trade lifetime in exchange for cure. The overall mean time trade-off utility was 0.925. Among BAMD, 75 % were willing to trade, utility was 0.917. Among AMB + AMD, 38 % accepted risk of death in exchange for cure, overall mean standard gamble utility was 0.999. Among BAMD, 49 % accepted risk of death, utility was 0.998. Utility was not related to visual acuity but it was to age (p = 0.02).
  
  
  CONCLUSIONS
  Elderly patients with BVI, caused by persistent amblyopia and age-related macular degeneration (AMD) or by bilateral AMD, had an approximately 8 % loss of TTO utility. Notably, the 8 % loss in elderly with BVI differs little from the 3.7 % loss we found previously in 35-year-old persons with unilateral amblyopia with good vision in the other eye. The moderate impact of BVI in senescence could be explained by adaptation, comorbidity, avoidance of risk and a changed percept of cure.
authors.affiliation: Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, NL-3000 CA, Rotterdam, The Netherlands.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: van de Graaf
authors.affiliation: Department of Ophthalmology, Admiraal de Ruyter Hospital, PO Box 3200, NL-4380 DD, Vlissingen, The Netherlands.
authors.forename: Dominiek D G
authors.initials: DDG
authors.lastname: Despriet
authors.affiliation: Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, NL-3000 CA, Rotterdam, The Netherlands.
authors.forename: Caroline C W
authors.initials: CCW
authors.lastname: Klaver
authors.affiliation: Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, NL-3000 CA, Rotterdam, The Netherlands. Simonsz@compuserve.com.
authors.forename: Huibert J
authors.initials: HJ
authors.lastname: Simonsz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000550:Amblyopia / Q000523:psychology*; D001294:Attitude to Health; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000209:etiology / Q000523:psychology*; D015354:Vision, Low / Q000523:psychology; D014792:Visual Acuity
keywords: Age-related macular degeneration; Amblyopia; Bilateral visual impairment; Elderly; Patient-reported utilities