PT  - JOURNAL ARTICLE
AU  - Huang, Haishun
AU  - Lin, Junxiong
AU  - Luo, Man
AU  - Li, Zhidong
AU  - Zhu, Yingting
AU  - Han, Jiaxu
AU  - Jin, Ling
AU  - Li, Yiqing
AU  - Zhuo, Yehong
TI  - Development and validation of the 40-item Glaucoma Visual Functioning Questionnaire
AID  - 10.1136/bjophthalmol-2021-320985
DP  - 2023 Aug 01
TA  - British Journal of Ophthalmology
PG  - 1086--1091
VI  - 107
IP  - 8
4099  - http://bjo.bmj.com/content/107/8/1086.short
4100  - http://bjo.bmj.com/content/107/8/1086.full
SO  - Br J Ophthalmol2023 Aug 01; 107
AB  - Aims To evaluate the psychometric properties of a newly designed questionnaire, the 40-item Glaucoma Visual Functioning Questionnaire (GVFQ-40), in a Chinese sample to capture the visual ability of patients with glaucomatous vision impairment in five domains.Methods Eighty-four glaucoma suspects (controls) and 270 glaucoma patients were recruited from the Glaucoma Clinic at Zhongshan Ophthalmic Centre in this cross-sectional, observational study. All subjects completed two questionnaires during routine clinical visits: the GVFQ-40 and the validated National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25). The discriminant, criterion-related and construct validity of the GVFQ-40 were assessed. A subset of subjects completed the GVFQ-40 twice, with an interval of 7–21 days, to determine test–retest reliability.Results Domain-specific and total GVFQ-40 scores were significantly higher (worse visual ability) in glaucoma patients than in controls (all p<0.001). All pairwise subgroup comparisons were statistically significant except for the ‘mobility’ domain comparison between the mild visual field loss and control groups (p=0.189). Significant differences between these two groups were observed in only 2 of the 12 dimensions on the NEI VFQ-25. The GVFQ-40 results demonstrated strong correlations with better-eye mean deviation and Visual Field Index (glaucoma severity measures). Exploratory factor analysis tended to confirm a three-domain structure. Test–retest intraclass correlation coefficients were higher than 0.927 for domain-specific and total GVFQ-40 scores.Conclusions The GVFQ-40 possesses good validity and reliability. It can be used to evaluate the impact of glaucomatous damage on visual ability and has potential in the evaluation of intervention efficacy.Trial registration number NCT04722861.Data are available on reasonable request. The data that support the results of this study are available from the corresponding author on reasonable request.