Testing of a Functional Outcome Measure for Those With Visual Field Defects

Overview

This study is designed in two Phases. In phase 1, the Functional Outcome Measure will be tested to determine its validity and reliability in three populations, subjects that have not had a stroke and have no visual field defect, subjects that have had a stroke but do not have a visual field defect, and lastly subjects that have had a stroke and have a visual field defect. The second phase will employ an amended version of the functional outcome measure to be administered to two groups of subjects. The first group of subjects will be those subjects diagnosed with a visual field defect from retrochiasmatic insults and they will perform vision restoration therapy. The second group with a similar diagnosis to the first but who do not undergo vision restoration therapy.

The study will be conducted over 18 months and will be conducted in two phases: Phase 1 In the first phase, we will determine the validity and reliability of Functional Outcome Measure by applying the Functional Outcome Measure to 20 subjects with homonymous visual field defects (VFD) due to a stoke, 20 stroke cases without visual field defects and 20 normal individuals. They will be asked to perform the Functional Outcome Measure a second time within the following 1-2 weeks in order to evaluate test-retest reliability. The expectation is that those without VFD (stroke and normal individuals) will have good or excellent results on the Functional Outcome Measure, while those with VFD will have abnormal results, thus reflecting the ability of this instrument to record the impairment present in those with VFD. In addition, it is anticipated that the results will be similar after retesting, ensuring test-retest reliability. An interim analysis will determine if the instrument is valid and if all its components correlate with the magnitude of visual field loss (as measured by High Resolution perimetry). Once the validation of the instrument has been accomplished, the functional outcome measure will be amended as suggested by this analysis to include only the items that correlate well with VFD. The functional outcome measure will be administered either at the NovaVision, Inc. office (normal individuals) or in cooperating medical centers (stroke patients with or without visual field defect). Phase 2 In the second phase, the amended version of the Functional Outcome Instrument will be administered to individuals with VFD. Two groups will be studied: 100 cases which will perform Vision Restoration Therapy (VRT), and 50 controls that will not. The latter group will include the 20 patients with VFD studied in Phase 1. Both groups will undergo visual field testing with high resolution perimetry, and will complete the Functional Outcome Measure on 4 occasions: twice within a 2 week interval at baseline, once after three months, and once after 6-7 months, with one of the groups having completed therapy during this time. Visual field testing (high resolution perimetry) will be administered at cooperating medical centers. While patients undergoing VRT will perform the functional outcome measure once at the center and once on their VRT device at home, controls will perform their functional outcome measure at the medical center only, as they don't have access to a VRT device at home.