Background: Visual disturbances very often accompany of multiple sclerosis (MS) and affect patients' quality of life (QoL). There have been no tools for investigation of the effect of visual disturbances on QoL in MS patients available in Poland. The aim of this study was validation analysis of Polish adaptation of Visual Function Questionnaire VFQ-25.

Methods: VFQ-25 published by Mangione in 2001, consists of 25 questions concerning general well-being, assessment of vision, social functioning, mental health, and self-sufficiency. According to the applicable translation principles, the original English version was adapted into Polish, and validation analysis of the convergent validity as well internal reliability was carried out. 108 randomly selected patients, diagnosed with MS according to McDonald's criteria were included in this study: 63 women and 45 men aged on the average 37.8 +/- 9.2 years, with mean disease duration of 11.2 +/- 5.6 years. All patients underwent assessment of disability based on Expanded Disability Status Scale (EDSS). Besides the analyzed VFQ-25 questionnaire, the patients completed also the Functional Assessment of Multiple Sclerosis (FAMS) questionnaire and SF-36 Health Survey.

Results: The internal consistency of the questionnaire was satisfactory (Cronbach's alpha reached 0.95). The accuracy of the scale was confirmed by positive correlations of the results between VFQ-25 and EDSS, FAMS and SF-36.

Conclusions: Statistical analysis has demonstrated that the Polish version of VFQ-25 is a valuable tool for investigation of the effect of visual disturbances on QoL in MS patients.