title: Validation of an instrument to assess visual ability in children with visual impairment in China.
abstract: To validate a visual ability instrument for school-aged children with visual impairment in China by translating, culturally adopting and Rasch scaling the Cardiff Visual Ability Questionnaire for Children (CVAQC).
  
  
  
  The 25-item CVAQC was translated into Mandarin using a standard protocol. The translated version (CVAQC-CN) was subjected to cognitive testing to ensure a proper cultural adaptation of its content. Then, the CVAQC-CN was interviewer-administered to 114 school-aged children and young people with visual impairment. Rasch analysis was carried out to assess its psychometric properties. The correlation between the CVAQC-CN visual ability scores and clinical measure of vision (visual acuity; VA and contrast sensitivity, CS) were assessed using Spearman's r.
  
  
  
  Based on cultural adaptation exercise, cognitive testing, missing data and Rasch metrics-based iterative item removal, three items were removed from the original 25. The 22-item CVAQC-CN demonstrated excellent measurement precision (person separation index, 3.08), content validity (item separation, 10.09) and item reliability (0.99). Moreover, the CVAQC-CN was unidimensional and had no item bias. The person-item map indicated good targeting of item difficulty to person ability. The CVAQC-CN had moderate correlations between CS (-0.53, p<0.00001) and VA (0.726, p<0.00001), respectively, indicating its validity.
  
  
  
  The 22-item CVAQC-CN is a psychometrically robust and valid instrument to measure visual ability in children with visual impairment in China. The instrument can be used as a clinical and research outcome measure to assess the change in visual ability after low vision rehabilitation intervention.
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.|Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China.
authors.forename: Jinhai
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.|Discipline of Optometry, Flinders University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Jyoti
authors.initials: J
authors.lastname: Khadka
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Rongrong
authors.initials: R
authors.lastname: Gao
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Sifang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Wenpeng
authors.initials: W
authors.lastname: Dong
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Fangjun
authors.initials: F
authors.lastname: Bao
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Haisi
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.|Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China.
authors.forename: Qinmei
authors.initials: Q
authors.lastname: Wang
authors.affiliation: School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.|Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Discipline of Optometry, Flinders University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Konrad
authors.initials: K
authors.lastname: Pesudovs
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China; D004185:Disability Evaluation; D006801:Humans; D015995:Prevalence; D015203:Reproducibility of Results; D018434:Sickness Impact Profile; D015354:Vision, Low / Q000175:diagnosis*; D014792:Visual Acuity; D019987:Persons with Visual Disabilities
keywords: Child health (paediatrics); Low vision aid; Vision