Cross-Validation of the Turkish Version of the 28-Item Impact of Vision Impairment Profile Test

Purpose: To translate the original 28-item Impact of Vision Impairment Profile into Turkish and to investigate its validity and reliability. Methods: Patients with no limitations to respond and affected by a chronic eye disease including retinitis pigmentosa (RP), age-related macular degeneration (ARMD) and diabetic macular edema which cause low vision were enrolled. The Turkish version of the IVI test was administered to all participants. The linguistic translation followed the international guidelines of forward and backward translation. 256 subjects who had a Snellen visual acuity of 6/12 or worse in the eye with best corrected visual acuity (BCVA) completed the Turkish version of the IVI-28 item. Psychometric evaluation of the Turkish IVI test involved the assessment of internal consistency, test-retest reliability, convergent and known-groups validity. Results: The mean (±SD) age of the participants was 53.67 ± 17.22 years. There were 256 patients with one of the following conditions: 105 RP (41%), 77 ARMD (30%), 74 DME (29%). Patients with lower visual acuity (VA) had lower index scores than those with higher VA (p = 0.001), which showed a sufficient responsiveness. Conclusion: Statistical analysis showed that Turkish version of the IVI-28 item is a valid and reliable instrument to measure vision-related quality of life (VRQoL) in patients with low vision.