The Italian version of the 25-item National Eye Institute Visual Function Questionnaire: Translation, validity, and reliability

Objective: To test the Italian adaptation of the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25) and to investigate its validity and reliability. Methods: This prospective observational study enrolled nonhospitalized patients with 1 of 5 chronic eye diseases, and a reference sample of subjects without eye diseases. Eligible participants had to be cognitively able to respond to a health status interview and be affected by 1 of the following eye conditions: senile cataract, age-related macular degeneration, glaucoma, diabetic retinopathy, and cytomegalovirus retinitis or low vision. A control group was composed of subjects with no evidence of underlying eye diseases. The Italian self-administered versions of Medical Outcomes Study Short Form and of the NEI-VFQ 25 were administered to all participants. Reliability and validity of the Italian translation of the NEI-VFQ 25 were tested using statistical methods. Results: Statistical analysis points out that the Italian version of the NEI-VFQ 25 has good validity, discriminatory power, internal consistency, and reliability. Conclusions: This Italian version of the NEI-VFQ 25 shows psychometric properties comparable to those of the American version, and thus can be used in clinical research as a specific measure of quality of life in patients with chronic eye diseases.