Abstract
Purpose: :
Studies of low vision device use have been conducted primarily in veteran populations or outside the U.S. The purpose of this study was to assess device usage rates and factors related to abandonment in a U.S. outpatient low vision population.
Methods: :
A telephone survey instrument was developed to measure usage rates of low vision devices for near tasks prescribed in U.S. outpatient clinics. The instrument assesses timing and frequency of device use, nature of the near task for which the device is used, payment type, and reasons for abandonment. In a multi-center pilot study the survey was administered to 88 patients who had been prescribed a total of 114 magnification devices at four separate clinical sites. The survey was administered again to a subset of patients to assess repeatability. Device abandonment was defined as no use in the past three months. Wilcoxon rank sum and Fisher’s exact tests were performed to investigate differences between those who had abandoned a device and those who had not.
Results: :
Mean (±SD) visual acuity at examination was 0.61±0.29 logMAR and mean age was 77±17 years. Mean time between device prescription and survey was 11±3 months. Of 114 prescribed devices, 81% had been used within the previous three months (71% within previous week). Device abandonment was not associated with age (p=0.863), time since prescription (p=0.125), visual acuity (p=0.804), or category of magnification device (spectacle, handheld, stand, or video) (p=0.412). There was a significant association between documented non-central visual field loss and abandonment of magnification device (7/19 in non-users and 10/69 in users; p=0.046).Repeat administration of the survey resulted in the same abandonment classification in 15 of 15 patients (100%).
Conclusions: :
Visual field loss was associated with device abandonment. The survey instrument appears repeatable for documenting abandonment. Usage rates were comparable to those that have been found previously in other populations.
Keywords: low vision • clinical (human) or epidemiologic studies: outcomes/complications • visual fields