Validation of Malay-vision disability assessment (VDA) questionnaire and its application to assess the functional disability among cataract patients of a tertiary medical centre in Malaysia

This study aims to translate, culturally adapt, and validate the Malay-Visual Disability Assessment (VDA) questionnaire and to assess its applicability in evaluating functional disability among cataract patients of a tertiary medical centre in Malaysia. This cross-sectional, questionnaire-based study was divided into two phases. In Phase I, the pre-final version of Malay-VDA was validated by a panel of six experts, followed by cognitive debriefing with 10 respondents. Test–retest reliability was assessed using 35 participants. The reliability and validity of the Malay-VDA was tested using intraclass correlation coefficient (ICC) and content validity index (CVI). Phase II evaluated the visual function among 200 cataract patients using the validated Malay-VDA. Additionally, self-administered questionnaire was used to collect sociodemographic data of the respondents. In Phase I, all items in Malay-VDA achieved an item-level CVI of > 0.8 for relevance and > 0.7 for clarity, with an overall CVI > 0.9. The test–retest reliability analysis demonstrated excellent reliability, with a single measures ICC of 0.998 (95% CI: 0.995–0.999, p < 0.001) and an average measures ICC of 0.999 (95% CI: 0.998–0.999, p < 0.001). In Phase II, out of the 200 respondents, they were more Chinese, females, had completed primary education and aged between 70 to 79 years. The respondents had higher VDA scores in distance domain with the mean (SD) scores of 16.57 (5.11), showing worst functional disability in distant activities, followed by difficulties in the mobility domain (mean (SD) scores of 10.15 (3.72)) and near domain (mean (SD) scores of 9.98 (2.76)). The mean score was found to be significantly higher in the poor vision group for all three domains. A positive correlation with moderate strength was found between total VDA score and best-corrected visual acuity (BCVA) with age adjusted (r = 0.575, p < 0.001). The Malay-VDA demonstrated good reliability and validity, making it a suitable tool for local adaptation. This study highlighted that visual function was not solely determined by visual acuity, underscoring the importance of comprehensive functional assessment in cataract patients. Therefore, integrating visual function assessment into preoperative evaluations could enhance surgical decision-making.