Developing patient-relevant outcome measures for clinical trials of sight-restoring interventions in very low and ultra-low vision
Epidemiology and Medical Biometry/Statistics
Final Report Abstract
In vision restoration trials, evaluating the treatment success of new technologies like gene- and cell based therapies or prosthesis is challenging as conventional ophthalmological endpoints fall short of capturing small changes in patients with very low vision. Patient-reported outcome measures (PROMs) and performance-based tests (PBTs) are alternatives to conventional tests of function but need to be better assessed in terms of their test characteristics before use in vision restoration trials. The PROM Impact of Vision Impairment-Very Low Vision (IVI-VLV) and the PBT Instrumental Activities of Daily Living – Very Low Vision (IADL-VLV) were developed to specifically target a very-low vision population. In previous studies both showed to be valid and reliable instruments, but their test-retest reliability has not been investigated yet. So we repeatedly administered both instruments to patients with stable severe vision impairment and assessed test characteristics including test-retest reliability. The IVI-VLV consists of two subscales measuring two different aspects of Vision related Quality of Life (VrQoL), namely emotional well-being (EWB) and activities of daily living and mobility (ADLM). Comparing the results to benchmark literature, both subscales of the IVI-VLV and the IADL-VLV showed excellent test-retest reliability. Our analyses did not indicate any systematic biases. We could shorten the former 29-items version of the IADL-VLV to an 11-item version, reducing the average test time from 5 to 1.5 minutes. Our study contributes to both instruments being among the best validated available tools in their fields and the study results support further use of the IVI-VLV and the IADL-VLV in a very- and ultra-low vision population.
Publications
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Instrumental Activities of Daily Living Tools in Very-Low Vision: Ready for Use in Trials?. Pharmaceutics, 14(11), 2435.
Terheyden, Jan Henrik; Fink, David J.; Pondorfer, Susanne G.; Holz, Frank G. & Finger, Robert P.
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Test–Retest Reliability of the Impact of Vision Impairment–Very Low Vision Questionnaire. Translational Vision Science & Technology, 12(6), 6.
Fink, David J.; Terheyden, Jan H.; Pondorfer, Susanne G.; Holz, Frank G. & Finger, Robert P.
