Abstract
Purpose: :
Use of patient-report outcome (PRO) measures, such as the NEI VFQ-25, is increasing in research studies and clinical trials in ophthalmology. In some studies, the VFQ-25 results have been compared to visual acuity or, less commonly, contrast sensitivity, at one or more time-points, but comparisons between VFQ-25 results and functional vision measures are relatively uncommon in the literature. A recent study (Barnes et al., ECVP) showed that the scores for many of the ‘Activity’ questions on the VFQ-25 (questions 5 to 14) correlated significantly with the response times and accuracies on tests of face discrimination and visual search, for a group of patients with AMD. In the present study, the VFQ-25 scores of AMD patients were compared with their reading performance on the MNRead and Pepper reading tests.
Methods: :
23 individuals diagnosed with AMD (mean age 79 years) had vision testing performed with binocular viewing. The visual impairment tests were: visual acuity (ETDRS) and contrast sensitivity (Pelli-Robson or Rabin charts). Functional vision tests: Minnesota Low Vision Reading Test (MNRead test), and Pepper Visual Skills for Reading Test. The outcome measures for these were the critical print size (CPS) and maximum reading rate on MNRead (MN rate), and the accuracy (% correct- PC) and reading rate (P rate) on the Pepper test. Values for the CPS and MN rate were calculated as the averages of the by-eye estimates for three investigators. All participants were asked the VFQ-25 questions by one of the researchers, with the focus here on the Activity scores, particularly question 5 (Q5), which deals with difficulty in reading newsprint.
Results: :
Visual acuity contributed significantly to the variances in both MN rate and P rate, and to CPS (r2 values from 0.42 to 0.54; p≤0.001), but not to PC. The Q5 scores were significantly correlated with all four of the reading measures (r values from 0.61 to 0.72; p≤0.002). Unlike results with the face discrimination and visual search tests, the four reading measures showed few correlations with the scores on the other Activity questions (even Q6 regarding ‘seeing well up close’) or with the "near activities" subscale.
Conclusions: :
The correlation between the VFQ-25 Q5 scores and measured performance on these two reading tests shows that there is consistency between self-rated reading ability and the speed, print size and accuracy of reading. These results further demonstrate the relationship between PRO measures and controlled testing of functional vision.
Keywords: reading • quality of life