Maberley D A L, Hollands H, Chuo J, Tam G, Konkal J, Roesch M, Veselinovic A, Witzigmann M, Bassett K
Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Eye (Lond). 2006 Mar;20(3):341-6. doi: 10.1038/sj.eye.6701879.
The purpose of this study was to ascertain the prevalence and primary causes of visual impairment in a representative Canadian population.
We reviewed a representative sample of patients who attended ophthalmologists' offices in a medium-sized Canadian city between 1996 and 2001 in order to estimate the prevalence of visual impairment. Demographic data, visual diagnoses, best-corrected visual acuities (BCVA), and visual field information were recorded. Visual status was categorized based on accepted World Health Organization (WHO) and North American criteria. Population data were obtained from the Canadian census.
The prevalence of low vision and blindness in our population was 35.6 and 3.8 per 10 000 individuals, according to the WHO classification, and 71.2 and 23.6 per 10 000 individuals, using the North American definition. Among individuals with some vision loss (vision worse than 20/40), cataract and visual pathway disease were the most common causes, together accounting for 40% of visual impairment. Age-related macular degeneration and other retinal diseases were the next most common causes of vision loss. Diabetic retinopathy and glaucoma were less frequently encountered as causes of visual impairment.
The overall prevalence of low vision and blindness in Canada are in keeping with data from large population-based studies from other developed nations. Cataract, visual pathway disease, and macular degeneration are the leading causes of visual impairment. These results are important for enhancing our understanding of the scope of vision health in Canada and may direct future health planning and cost-utilization research.
本研究旨在确定加拿大代表性人群中视力损害的患病率及主要病因。
我们回顾了1996年至2001年间在加拿大一个中等规模城市的眼科医生诊所就诊的患者的代表性样本，以估计视力损害的患病率。记录了人口统计学数据、视力诊断、最佳矫正视力（BCVA）和视野信息。根据世界卫生组织（WHO）和北美的公认标准对视力状况进行分类。人口数据来自加拿大人口普查。
根据WHO分类，我们人群中低视力和失明的患病率分别为每10000人35.6例和3.8例，按照北美定义则为每10000人71.2例和23.6例。在有一定视力丧失（视力低于20/40）的个体中，白内障和视觉通路疾病是最常见的病因，共占视力损害的40%。年龄相关性黄斑变性和其他视网膜疾病是其次最常见的视力丧失病因。糖尿病视网膜病变和青光眼作为视力损害病因较少见。
加拿大低视力和失明的总体患病率与其他发达国家基于大规模人群研究的数据一致。白内障、视觉通路疾病和黄斑变性是视力损害的主要原因。这些结果对于增强我们对加拿大视力健康范围的理解很重要，可能会指导未来的健康规划和成本利用研究。
