FLORA™: Phase I development of a functional vision assessment for prosthetic vision users

Abstract

Background Research groups and funding agencies need a functional assessment suitable for an ultra-low vision population in order to evaluate the impact of new vision restoration treatments. The purpose of this study was to develop a pilot assessment to capture the functional vision ability and well-being of subjects whose vision has been partially restored with the Argus II Retinal Prosthesis System. Methods The Functional Low-Vision Observer Rated Assessment (FLORA) pilot assessment involved a self-report section, a list of functional vision tasks for observation of performance, and a case narrative summary. Results were analyzed to determine whether the interview questions and functional vision tasks were appropriate for this ultra-low vision population and whether the ratings suffered from floor or ceiling effects. Thirty subjects with severe to profound retinitis pigmentosa (bare light perception or worse in both eyes) were enrolled in a clinical trial and implanted with the Argus II System. From this population, twenty-six subjects were assessed with the FLORA. Seven different evaluators administered the assessment. Results All 14 interview questions were asked. All 35 functional vision tasks were selected for evaluation at least once, with an average of 20 subjects being evaluated for each test item. All four rating options -- impossible (33%), difficult (23%), moderate (24%) and easy (19%) -- were used by the evaluators. Evaluators also judged the amount of vision they observed the subjects using to complete the various tasks, with vision only occurring 75% on average with the System ON, and 29% with the System OFF. Conclusion The first version of the FLORA was found to contain useful elements for evaluation and to avoid floor and ceiling effects. The next phase of development will be to refine the assessment and to establish reliability and validity to increase its value as a functional vision and well-being assessment tool.

Five-Year Safety and Performance Results from the Argus II Retinal Prosthesis System Clinical Trial

“…The FLORA and VisQoL were performed only through post-implant year 3 (as per the clinical trial protocol), and the FLORA has been described and reported elsewhere. 10,11 The Activity Inventory was not fully validated in this patient population (e.g., with very low vision patients) and as such the data are not included in this report.…”

An analysis of observer‐rated functional vision in patients implanted with the Argus II Retinal Prosthesis System at three years

“…Therefore, the Functional Low‐Vision Observer Rated Assessment (FLORA) instrument was developed specifically for use in patients implanted with retinal prostheses who suffer from profound loss of vision or blindness. The structure and development of FLORA has been previously published . The instrument combines a self‐report section (Part 1) with a list of functional visual tasks that are rated by a qualified evaluator (Part 2).…”

Progress in the clinical development and utilization of vision prostheses: an update

“…The Argus II clinical trials have also included a new functional low-vision observer-rated assessment, which combines visual tasks scoring (eg, mobility tasks and activities of daily living), self-reported user experience, and case-study assessment (a modified quality of life questionnaire)27 by a rehabilitation expert, which showed 80% of patients reported that the device had a positive impact on their daily life at the 1-year follow-up 3…”