Purpose: To determine how glaucoma patients with various degrees of vision loss rate their vision, and to determine if the Esterman binocular visual field test and other visual function tests correlate with those ratings.
Methods: Two hundred thirty-seven glaucoma patients evaluated their vision using 2 utility tests, the linear rating scale and the time trade-off test, and 2 quality-of-life instruments, the National Eye Institute Visual Function Questionnaire (VFQ) and the Short Form 36 (SF-36). Their results were compared to clinical tests of their vision and to persons with normal vision (n = 12) and blind persons (n = 12).
Results: On a scale of 0 (blind) to 100 (ideal), subjects with normal vision rated their vision higher (90 +/- 8.0) than did glaucoma subjects and suspects (75.7 +/- 17.6) and "blind" subjects (15.6 +/- 15.3), P = .001. Mean scores for the Esterman test were 89.7 +/- 13.4 for the glaucoma group. The Esterman test correlated moderately with the overall VFQ score (partial correlation coefficient [PCC] = 0.32, P = .001), but only weakly with the linear rating scale (PCC = 0.17, P = .02) and the time trade-off test (PCC = -0.16, P = .06). Correlation between the linear rating scale and the overall VFQ score was good (PCC = 0.56, P = .0001) and was moderate with several domains of the SF-36 (e.g., social function PCC = 0.32, P = .0001).
Conclusions: Utility values that glaucoma patients assign to their vision do not correlate well with Esterman test results. A challenge for the future will be designing clinical tests that better correlate with patient perceptions.