Abstract
Purpose: :
Standard utility instruments capturing vision specific utilities such as time trade-off or standard gamble have a number of short comings. As there are currently no other instruments available in German, we evaluated the German version of the VisQol ,a six item vision-specific utility questionnaire.
Methods: :
The German VisQol was self-administered in 290 patients and 252 controls. All subjects underwent a full ophthalmological examination including best-corrected visual acuity (VA). At this stage, a descriptive analysis was performed, examining distribution and correlations of raw VisQol scores using SPSS 19 software (SPSS Inc, Chicago, Ill, USA) .
Results: :
Most patients suffered from retinal diseases (diabetic retinopathy (n=105, 36.2%), age-related macular degeneration (n=94, 32.4%), retinal vessel occlusion (n=15, 5.2%)), followed by cataract (n=16, 5.5%) and glaucoma (n=17, 5.9) and other diseases (n=43, 14.8%). Mean VisQol and logMAR VA score in the patients' group was 0.81 +/- 0.18 (SD) and 0.36 +/- 0.35, respectively, and 0.98 +/- 0.04 and 0.07 +/- 0.01 in the control group. For patients, there was a highly significant correlation between the VisQol score and mean logMAR VA (Spearman rho = -0.365, p<0.001). For the control group, the VisQol score and mean logMAR VA were not correlated (Spearman rho = 0.02, p=0.80). Highest VisQol values were found in the glaucoma (0.93 +/- 0.11) and cataract (0.89 +/- 0.12) subgroup, lowest VisQol values were found in the vessel occlusion (0.76 +/- 0.17) and AMD (0.79 +/- 0.18) subgroup.
Conclusions: :
The German VisQoL captures differences between patients and controls, as well as between different conditions. In patients, utility values are lower in macular diseases when central VA is affected compared to peripheral or diffuse visual defects. Applying VisQol derived utilities to economical evaluations might help to generate more reliable results than standard utility testing in ophthalmology. A more comprehensive psychometric evaluation including other utility measures is currently under way.
Keywords: quality of life • visual acuity