JMIR Publications

ABSTRACT

Background:

Self-reported questions on blindness and vision problems are collected in many national surveys and may serve as important indicators for surveillance of visual health. However, the validity of these measures to predict prevalence and disparities in objectively measured visual function is unknown.

Objective:

To estimate the accuracy of self-reported vision loss measures fielded in national surveys compared to evaluated best-corrected visual acuity (BCVA) at both the individual and population level.

Methods:

We calculated measures of accuracy and correlation between self-reported visual function versus BCVA, on both an individual and population basis among University of Washington ophthalmology or optometry clinic patients with a prior eye examination, randomly selected with oversampling for visual acuity loss or diagnosed eye diseases. Self-reported visual function was collected via a telephone survey. BCVA was determined based on retrospective chart review. This study was approved by the Institutional Review Board at the University of Washington.

Results:

The survey question “Are you blind or do you have serious difficulty seeing, even when wearing glasses?” had the highest accuracy among patients with blindness (BCVA ≤20/200), while the highest accuracy for detecting any vision loss (BCVA <20/40) was achieved by responses of “fair”, “poor” or “very poor” to the question “At the present time, would you say your eyesight, with glasses or contact lenses if you wear them, is excellent, good, fair, poor, or very poor”. On a population level, prevalence rates based on these two questions were highly correlated to prevalence based on BCVA among all sociodemographic groups.

Conclusions:

While survey questions may not be sufficiently accurate to be used as a diagnostic test at the individual level, survey questions may accurately reflect demographic and socioeconomic variation in underlying BCVA and can be used to enhance population surveillance of vision loss.