Table 2.
Patient-reported outcome measures (PROs) that have previously been used in retinal prosthesis clinical trials.
| Patient-reported outcome (PRO) | Details |
|---|---|
| Ultra-low vision visual functioning questionnaire (ULV-VFQ) (Dagnelie et al. 2017b; Jeter et al.,2017) | This instrument was developed on the basis of extensive focus group interviews with patients whose bestcorrected vision did not allow them to see the largest letters on the chart at 0.5 m distance (VA < 20/1600), but who could at least tell the difference between day and night (Adeyemo et al., 2017). The instrument has demonstrated robust performance for both native ULV and prosthetic vision, and even for substitute vision in users of the Brainport tongue sensor (Dagnelie, unpublished observation). In addition to the original 150-item version of this questionnaire, shorter versions with 50 and 23 items are available |
| Forty-eight item Veterans Administration low vision visual functioning questionnaire (VALVVFQ-48) (Stelmack et al. 2004) | This instrument was developed for a population with moderate to profound vision loss, but with preserved form vision (20/70 – 20/800) and has been extensively used in low vision rehabilitation (Stelmack and Massof, 2007). While this instrument may be out of range for most visual prosthesis users, it is a good complement to the ULV-VFQ for those whose improvement puts them beyond the range of the ULV-VFQ |
| Impact of vision impairment questionnaire (IVI) (Lamoureux et al. 2006) | This instrument was designed to measure emotional and healthrelated effects of visual impairment as well as functional ability, and it has been used extensively in populations with mild to severe lo vision (20/70 – 20/400) |
| Impact of vision impairment – very low vision (IVI-VLV) (Finger et al. 2014b) | This adaptation of the IVI to populations with more profound visual impairment was developed specifically for use in a population that might participate in the Australian visual prosthesis trials. The range of this instrument may not be adequate for this purpose, since all but a few items rely on form vision, at levels that many current visual prosthesis users do not reach |