Abstract
Purpose: :
Best corrected visual acuity (BCVA) is easy to perform and to measure. The study was performed to give an impression how valid BCVA is to reflect visual performance and vision-related quality of life in patients with age related macular degeneration (AMD).
Methods: :
A retrospective cross sectional study was performed comparing visual outcome (as measured by BCVA) after anti-VEGF therapy for AMD with self reported vision related quality of life (measured with the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) focussing on subscales "near vision" and "distance vision" -both consisting of 3 questions respectively). 200 customers of a german health insurance company were asked to take part in the study, the response rate was 38.5%.Visual outcome was categorized in 2 groups: Group BS (n=40) if BCVA was better or stabilized after injections, group W (n=36) if BCVA was worse after injections. Average (AV) and median for subscales "distance vision" and "near vision" were calculated. To compare the subscale results in both groups, average mean difference, standard deviation (SD), 95% confidence interval (CI) and p-value were calculated by t-test.
Results: :
Group BS reached better results (AV 54,88/ SD26,95) in subscale "near vision" than group W (AV 49,03/ SD 26,65):the difference was not statistically significant but right-leaning CI suggested a relevant difference between both groups.In subscale "distance vision", however, group W revealed higher scores (AV 59,72/ SD 24,94) than group BS (AV 56,98/ SD 25,34).
Conclusions: :
Participants with stabilized or ameliorated BCVA did not outperform in both subscales of patient reported outcomes (PRO) but showed higher scores only in subscale "near vision". Although handy and pragmatic, BCVA does not seem to adequately reflect vision related quality of life in patients after intravitreal injection therapy for age related macular degeneration. Confounders, effect modifiers, power, bias, internal and external validity and clinical implication are discussed.
Keywords: age-related macular degeneration • quality of life • clinical (human) or epidemiologic studies: outcomes/complications